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	All 57 posts		Subject: Benzaldehyde + MEK acid catalyzed aldol		Please login to post		Down

		bio (Stranger) 08-03-03 05:28 No 451381				Benzaldehyde + MEK acid catalyzed aldol
						I am prepared to do the subject reaction with Bayer Villager oxidation to P2P. Where I am now I have no access to a library only the internet for references. Does anyone have anymore details on this procedure? I feel the sketchy details in Post 245942 (twodogs: "New method for P2P", Novel Discourse) are fraught with pitfalls and I sure don't want to waste my analytical grade $80 a liter PhCHO. Also I have been searching the internet for other catalysts other than Hydrogen Chloride which would be suitable for this type reaction to no avail. Any references or pointers would be highly appreciated. The Organic Reactions volumes referenced don't seem to be available on-line and the Patents referenced aren't very helpful. Anyway I will try it on a small scale soon and will let you all know how it turns out.
		twodogs (Newbee) 08-03-03 20:49 No 451488				Benzaldehyde + MEK
						Sketchy details?? Jesus Christ ...how much detail do you want? If you follow the procedure exactly as I have mentioned you will get a result.
		bio (Stranger) 08-05-03 01:07 No 451702				Benzaldehyde + MEK
						OK, Two Dogs thanks for the encouragment. Perhaps sketchy was a poor choice of words. So I assume you have had success with this reaction. It does seem fairly simple to do. Apparently a little H2O is not detrimental to the condensation product yield as they performed it in an open beaker at freezing temperature. This puzzled me somewhat as water is eliminated and usually I used a Dean Stark tube or at least a drying tube in a sealed system for similar PhCHO condensations. Also I wonder if the relatively low yields are partly due to doing atmospheric distillation. At those high temps it seems a lot of decomposition could occur. I will try a test batch tomorrow and see if it will crystallize after removing the excess MEK. If you have done this reaction could you share some more thoughts? I want to scale it up and think the oxidation step could get by with way less MeCOOH.
		twodogs (Newbee) 08-05-03 02:19 No 451718				Benzaldehyde + MEK acid catalyzed aldol (Rated as: good read)
						Bio...yes I have had sucess with this reaction but I felt that 35% was too low for me. The aldol condensation part is very easy and as I mentioned can be done with refluxing conc. HCl or with H2SO4 but you get the best result with dry HCl. With the oxidation part, I would use peracetic acid or performic acid if I were you as the perborate makes for a messy workup. If you use less Acetic with the perborate you will end up with such a solid mass that you won't be able to stir it. I don't do this shit any more but have a look at this site from time to time but I know two another ways to the ketone from the unsaturated ketone that is formed from the aldol condensation. The unsaturated ketone can be oxidised with NaOCl to give the alpha- methyl cinnamic acid. This can be decarboxylated to give phenyl propene that can be worked up with performic etc or the methyl cinnamic can be oxidised with oxone and the resulting epoxy acid decarboxylated to give the ketone. I was looking at these reactions when I figured out that the Baeyer-villager worked as well and that seemed easier. It is a pity you don't have a library handy as I think that the Baeyer-Villager would work much better with a catalyst.
		viki (Stranger) 08-05-03 03:49 No 451737				peracetic oxidation
						question for two dogs.what strength peracetic would you recommend for the oxidation?would 30-35 %work? viki
		twodogs (Newbee) 08-05-03 04:17 No 451739				Benzaldehyde + MEK acid catalyzed aldol
						Viki,yes that would work. Have a look at all the patents under Baeyer-Villager and you will see all the different oxidisers used. Boesken used peracetic.
		bio (Stranger) 08-06-03 03:32 No 451987				Benzaldehyde + MEK acid catalyzed aldol
						Yea, twodogs the peracetic makes sense. I bought some 30% H2O2 intending to try it or even regenerate the Na Perborate. Can the peracetic or performic be made insitu? and would the same molar ratios be used. Also I have the perborate tetrahydrate a monohydrate is also available, the 4 hydrate which is NaBO3.H2O2.3H20 is ca. 10% O2. What is the actual mole ratio needed of O2 for the Baeyer Villiger? Again thanks for your assistance as the library here is in the wrong language and only goes to the 10th grade (sic).
		twodogs (Newbee) 08-06-03 05:11 No 452010				Baeyer-Villager
						Bio I am sorry but this was a while ago and I don't have any notes. I would have thought that you would need at least 50% H2O2 to make a strong enough peracetic. Performic pretty much has to be made on the spot as it deteriorates quite quickly. Peracetic needs a catalyst like H2SO4 to form and that may need to be neutralised before use. I had alot of difficulty in figuring out the percentage of peracetic formed by combining H2O2 and acetic acid. A lot of posts on the topic here at the Hive I think are wrong in that they assume too high a percentage of peracetic in the final product. It is one of those reactions where 1+1 doesn't equal 2. I couldn't buy peracetic and this is the main reason why I went with the perborate as the quantities needed are easier to work out. Have a look at US Patent 4988825 where I got the idea of using perborate.
		Rhodium (Chief Bee) 08-06-03 09:16 No 452068				Peracid concentrations (Rated as: good read)
						See J. Am. Chem. Soc. 907 (1946) (https://www.rhodium.ws/pdf/peracid.pdf)
		twodogs (Newbee) 08-06-03 09:39 No 452069				Peracid concentrations
						Thanks Rhodium. That is what I had read.. if you use 90% H2O2 with acetic acid you can get the high concentrations of peracetic but 30% H2O2 only gives about 8%. I don't believe that you can buy 90% H2O2 any more. 35% peracetic seems to be the reaction grade.
		bio (Stranger) 08-07-03 04:33 No 452240				Peracid concentrations
						OK, twodogs and Rhodium, thanks for the references. Doing my research now. By the way Rhodium can P2P be distilled at atmospheric without decomposition (or only minimal)? I always used about 10 torr and it stayed water white for days.
		Rhodium (Chief Bee) 08-07-03 06:21 No 452251				P2P distillation
						Yes, P2P can be distilled without vacuum, but you might get 10% better yield by using vacuum. 10 mmHg is excellent in this case.
		bio (Stranger) 08-09-03 04:16 No 452559				Benzaldehyde + MEK acid catalyzed aldol
						Hi twodogs and Rhodium. The condensation went quite smoothly I added about half the HCL gas before the color change started and it was just as you said the next morning. I will try to crystallize my little test batch tonight without distilling. Did you ever have any luck with this? When I crystallized phenyl nitropropene w/o distillation it worked but only by seeding with a grain or two of fine sand and this without removing the solvent or chilling. I presume not as you mention the freezer trip. Anyway I will try it as it would save a lot of work especially when scaled to the proportions planned. PhCHO is sold as bacteriacide around here so it's about as common as formaldehyde.
		bio (Stranger) 08-09-03 20:57 No 452657				Benzaldehyde + MEK acid catalyzed aldol
						OK, It crystallized after freezing with scratching and seeding. Now trying to determine a suitable recrys solvent. Any ideas. Will try abs IPA and Hexane or Benzene first.
		Herr_Ovalmeister (Stranger) 08-15-03 00:28 No 453611				Post 208702 Post 451381 I've seen MEK (methyl...
						Post 208702 (Antoncho: "The easiest synth of benzaldehyde from toluene", Chemistry Discourse) I've seen MEK (methyl ethyl ketone) sold at one hardware store OTC.
		bio (Stranger) 09-09-03 01:36 No 457817				CeMolybdate
						The CeMolybdate vapor phase method is INMHO the best. See my other posts.
		chilly_willy (Hive Bee) 09-25-03 01:40 No 460868				tried this...
						Someone I know tried this reaction a while back.  Seemed too good to be true!  Was it?  During the condensation he found it impossible to weigh the gassed liquid to determine any amount of absorbed HCl.  Digi(good one) weighed NO appreciable weight change. <--missing something here??.. He just kept gassing and gassing until everything got blood red brown.  It was left overnight..washed, extracted, and distilled...a yellow oil was left over that still smelled like cherries.  What the hell??  Instinct told him something went wrong.  Anyway..for shits and giggles he left everything in some ice..and to his surprise the whole lot of yellow oil solidified the next day..still smelled like cherries..but crystals..yea!  The cherry-smelling sulfur crystals were added to the perborate w/ gaa..and heating started...a little too fast.  Whoops..a little boil-over.  Shit! vinegar smell all over..oh well..fan took care of that.  Heating was properly maintained..crap...the crystasls werent dissoving.  Kept heating.  Left for a couple hours...seemed as though perborate and cherry xtals didnt dissove at all.  That cant be right since the p2p comes from the cherry xtals...?  Dumped the whole mess.  What the hell happened?  Bio please post as to what happened during your oxidation step.  Ne1 else please enlighten as to what happened/went wrong.... <========>
		placebo (arrogant bee of the day) 09-25-03 10:26 No 460953				Or you could steam distill the p2p.
						Or you could steam distill the p2p. I'm not fat, I'm just too short for my weight. http://www.whatreallyhappened.com
		bio (Stranger) 10-08-03 02:54 No 463310				sodium perborate tetrahydrate
						two dogs.......Please could you clarify for me if the ca. 8% peracetic from 30% H2O2 will oxidize the ester we discussed, given the perborates ca. 10% H2O2? I did get the unsat ketone to crys w/o distill.
		bio (Stranger) 10-21-03 05:08 No 465882				it worked
						just like you said twodogs, thankyou very much. Only thing is I got a slightly better yield
		viki (Stranger) 11-06-03 04:23 No 469038				gassing MEK
						If one were scaling this reaction up would it work if  one were to gas say 3 litres of MEK first  a la Argox,  then add the MEK to the benzaldehyde say at a litre a time?Cheers Viki
		bio (Newbee) 11-06-03 18:23 No 469174				gassing MEK
						Seems like it should work but I don't see the point here(storage maybe?) The gassing took me over 3 hours for a 360g MePhBuO in a 2 liter RB using an ice salt bath to keep the temp about 5 deg +/-. Then it would probably heat up again when you add to the PhCHO. Maybe a colder bath would speed it up if it wouldn't get too cold. The left over MEK goes into the water wash. I was surprised to learn that MEK holds 24% water.......... To recycle do you know if distilling this MEK/HCL solution would damage the ketone?............. Or you could mix with the NaOH wash to neutralize as some is in there too. I only use AR chems and hate throwing it out but have been to busy to experiment with this idea. Also do a 1/2 vol sat salt wash to clear up the organic layer. This helps a lot. Once you have some seeds the MePhBuO crystallizes nicely at room temp if properly distilled. It's instantaneous.
		bio (Newbee) 11-08-03 02:07 No 469564				The left over MEK goes into the water wash
						Should have said a lot of it. You will get a small 74-84 deg fraction when distilling the MePhBuO (196ml of 750ml) in the last run. It is full of HCl even after washing with a 20% excess of lye.
		chilly_willy (Hive Bee) 11-15-03 03:06 No 470971				baeyer-villiger catalyst
						I just finished searching at the library for possible baeyer-villiger catalysts and have come up with one that might seem promising.  Ferric chloride.  Would using this alone with H2O2 stirring like mad do the job any better? Yield-wise I mean.  What about adding it in with the perborate in twodogs original procedure.  I am still tryiing to understand the dynamics of the lewis-acid here so please correct me or point out why either suggestion will or wont work.  Thx... <========>
		Rhodium (Chief Bee) 11-15-03 03:59 No 470981				I haven't memorized the entire literature
						Post the procedures/references you have found, so that we have something to work with. It is a little hard to give critique on something we haven't read...
		bio (Newbee) 11-15-03 04:25 No 470993				baeyer-villiger catalysts
						Would using this alone with H2O2 stirring like mad do the job any better? The oxidation is done by the per acid; acetic in this case.   What about adding it in with the perborate in twodogs original procedure. This sounds feasible, would probably want the anhydrous ferric chloride as water is a product of the condensation. What molar proportions were used in the examples you found? I would think very little as FeCl3 is a good Friedel Crafts reactant, not quite as strong as Aluminum chloride which might also work.
		bio (Newbee) 11-17-03 22:55 No 471446				Perborate oxidations of ketones
						SPC/SPB Post 446838 (GC_MS: "SPC/SPB", Novel Discourse) ............Read this Chilly Willy and if you or anyone else has acess to  Tetrahedron 1987,43,1753-1758 It is from the above article and is on room temp perborate oxidation of ketones to ketones in acetic acid at room temperature in good to excellent yields. I'm still searching for a an oxidation catalyst to try and have seen MnSO4 a couple times in .01-.1 molar ratio but it's not clear if this won't also oxidise the ketone itself.
		bio (Newbee) 11-24-03 22:24 No 472943				Benzaldehyde + MEK acid catalyzed aldol (Rated as: excellent)
						I don't have a lot of time to spend on this so if anyone sees any obvious boo boos please let me know. Just trying to repay my debt to the Hive. And clear my bad karma, how the hell did that happen? Results of latest twodogs reaction. 1) Methyl Phenyl Butanone (MePhBuO)...... 400g PhCHO and 600g MEK (both RA grade) were mixed in a 2L flask placed in an ice salt bath and cooled to -5 degrees. 80 grams of DRY HCL gas was passed over about 3 hours keeping the temp below 5-7 degrees. Stirring with the thermometer. (This is about a 1 to 2.2 mole ratio as given by twodogs. Rhodium has posted an apparent improvement of yield to 94% with 1 to 1 mole which has not been tried yet.) A saturated solution is what is strived for here. Previous results indicated about 85% of the calculated HCl was absorbed. An additional 15% was partly added to compensate and the solution was saturated before it was all added. Flask stoppered and left in bath to warm up overnight ca. 10 hours. The Vogel  method of dripping 37% HCl into 98% H2SO4 was used with a H2SO4 dryer. Trap also used but not needed this time. Vogel says 31-33g HCl per 100ml. 2) The resulting deep reddish brown reaction mix was washed with an equal volume of water separated then washed with a 20% excess of 10% NaOH separated then washed with 1/2 volume of brine separated and filtered to give 845ml Ph 7-8 solution. This was distilled at atmospheric collecting most of the first fraction 74-84 degrees PH1 and the second fraction at aspirator pressure most was collected 119-140 degrees. MePhBuO clear yellow fruity smelling oil 506.7 gram includes the forerun and after run. This was allowed to cool to ambient, then seeded causing immediate crystalization. Let set up in frig with stirring for a couple hours. Filter on buchner wash with 95% EtOH dried for 430 grams total very clean and dry light yellow (almost white) pleasant smelling crystals. These initially set up as long  transparent light yellow needles. Happy now as had expected only 360 grams. Even returned to the vac dessicator to insure they were dry. Recrys of a little test resulted in very little improvement. This stuff is easy to crys in a relatively pure form. No GC/MS sorry. 3) Baeyer-Villiger Oxidation....... To a 6 liter FB flask on the mag stirrer hotplate in a water bath was added 2.3L Glacial Acetic Acid (RA) 615g NaPerborate 4H2O and 430g MePhBuO with stirring. This starts endothermic and mag stirring is inadequate until heat is added and the stuff dissolves. Added the crystals over ca. 1/2 hour while heating to about 45 deg. After the induction period added ice and or heating periodically to keep the solution temp 55-65 deg.  Can get into this more later if anyone actually is ready to do it. Stir vigorously keeping the temp as above for 6 hours. If it gets hotter as long as controllable it's OK. Be very carefull here I already had a near runaway........ Proceed slowly and carefully........ Cool to ambient then either dilute with water or recover the NaBO2 and acid first. Now extract with toluene or DCM. I used DCM this time and wish I didn't. Anyway extracted with 1.2L DCM washed with water and brine then removed solvent to leave the enol ester. 4) Hydrolysis and P2P...... enol ester added to 2.25L 10% NaOH in 50/50 w/w EtOH/H2O and stirred 2 hours. Extracted with DCM 300/200/200ml (again wish I had used PhMe) washed with water and brine removed solvent and collected 162g P2P at aspirator pressure (almost all between 119-140 deg).     OVER
		bio (Newbee) 11-25-03 00:02 No 472961				collected 162g P2P
						correction......collected 169.5g...... did not drain completely...takes time you know
		twodogs (Newbee) 11-25-03 10:20 No 473050				Benzaldehyde + MEK acid catalyzed aldol
						Nicely done Bio. One thing that should be mentioned is that in the condensation step, over gassing leads to some sort of polymerisation...evidently. There is a paper mentioning this somewhere. This is why I stated the weight of dry HCl in my original post of the set of reactions instead of just saying gas the shit out of it.
		bio (Newbee) 11-25-03 18:36 No 473129				polymerization
						Well there is certainly a lot of the tarry polymer created using the 1 to ca.2 mole ratio. Perhaps going slower this time and watching temp more carefully and not taking out of the ice right away helped the yield. Also there could be a clue hidden in the reference to the gassing procedure (not given) which is the key to the 94% yield with only a trace of tar.  The statement regarding saturation was gleaned from the JACS 65,1824(1943) article Rhodium posted. I did notice that following your weights of HCL that saturation (or somewhere close) was reached very near the end. What was not stated in the synthesis part was the procedure or temp used when HCL gasing. There is a footnote to this article saying they followed this procedure.,,,,,,,,,,,(5) Muller and Harries, Ber., 36, 9BG (1902).,,,,,,,,,,,,if anyone could find this it would be very helpfull. Surely somebee has access to Ber. (berliner I think) and could dig it up to assist.
		psychokitty («») 10-11-04 06:41 No 535306				Making this reaction more OTC . . . (Rated as: good read)
						I think the value of the following patent speaks for itself. If it's already been posted before, please accept my apologies in advance.  I tried to use TFSE. ( 1 of 1 ) United States Patent 4,673,766 Buck ,   et al. June 16, 1987 Method of producing benzaldehyde Abstract A method is disclosed for producing benzaldehyde by fractionally steam distilling benzaldehyde from cinnamaldehyde in the presence of hydroxide catalyst and at a pH on the order of about 11 to about 13. Conversions of cinnamaldehyde to benzaldehyde can be achieved on the order of about 75% or more. Inventors: Buck; Keith T. (Cincinnati, OH); Boeing; Anthony J. (Cincinnati, OH); Dolfini; Joseph E. (Cincinnati, OH) Assignee: Mallinckrodt, Inc. (St. Louis, MO) Appl. No.: 856595 Filed: April 25, 1986 Current U.S. Class: 568/433; 568/458 Intern'l Class: C07C 045/51 Field of Search: 568/433,458 References Cited [Referenced By] Other References Guthrie et al., Can. Jour. Chem., vol. 62 (1984), 1441-1445. Primary Examiner: Helfin; Bernard Attorney, Agent or Firm: Wood, Herron & Evans Claims What is claimed is: 1. A method of making benzaldehyde com- prising dispersing cinnamaldehyde in water, converting the cinnamaldehyde to benzaldehyde under the action of heat in the presence of a catalytic amount of hydroxide ion and at a pH of about 11 to about 13, fractionally steam distilling benzaldehyde and acetaldehyde from the cinnamaldehyde, and recovering benzaldehyde from the distillate. 2. The method of claim 1 which is conducted at a pH in the range of about 12 to about 12.5. 3. The method of claim 1 wherein the benzaldehyde distillate resulting from the steam distillation is fractionally distilled for separation of the benzaldehyde in substantially pure form. 4. The method of claim 1 wherein the acetaldehyde is vaporized during the course of the conversion while the benzaldehyde is condensed. 5. The method of claim 1 conducted in the presence of an anionic surfactant. 6. The method of claim 1 conducted under shearing agitation to facilitate the dispersion of the cinnamaldehyde in the water. 7. A method of making benzaldehyde com- prising dispersing cinnamaldehyde in water in the presence of an anionic surfactant, agitating the dispersion under the action of heat in the presence of a catalytic amount of hydroxide ion and at a pH of about 12 to about 12.5 for the conversion of cinnamaldehyde to benzaldehyde, fractionally steam distilling benzaldehyde and acetaldehyde from the cinnamaldehyde in a still having a pot temperature of about 105.degree. C. and a column temperature of about 99.degree. C., and fractionally distilling the benzaldehyde from the distillate for the separation of substantially pure benzaldehyde to obtain a yield of at least about 75% based upon the cinnamaldehyde. 8. The method of claim 7 wherein cassia oil is employed as a natural source for the cinnamaldehyde employed in the conversion. Description BACKGROUND OF THE INVENTION The retroaldol reaction of cinnamaldehyde is well known. In this reaction, cinnamaldehyde is converted to benzaldehyde and acetaldehyde with various potential side reactions. Recently, for example, an investigation of the kinetics of the retroaldol reaction of cinnamaldehyde has been reported by J. Peter Guthrie, et al, Can. J. Chem., Vol. 62, pp. 1441-1445 (1984). While the conversion of the cinnamaldehyde to benzaldehyde has been long known and well studied, it has not been heretofore known to produce benzaldehyde from cinnamaldehyde in substantial yields and favorable reaction conditions for production of such yields have not been reported. SUMMARY OF THE INVENTION This invention is directed to a method of making benzaldehyde by conversion of cinnamaldehyde in the presence of water with surprisingly high yields heretofore unachieved. The invention involves the dispersion of cinnamaldehyde in water and, in the presence of an effective catalytic amount of hydroxide ion, fractionally steam distilling benzaldehyde from the cinnamaldehyde. The reaction is conducted at a pH on the order of about 11 to about 13 and, unexpectedly, within this pH range it has been discovered that a substantial conversion of cinnamaldehyde to benzaldehyde can be achieved on the order of about 75% or more. It has also been found that the conversion may be achieved at such a high pH without adverse side reactions. In a preferred mode of conducting the method, the cinnamaldehyde is dispersed in the water in the presence of shearing agitation and a surfactant. In another aspect of this invention, it is preferred to employ an anionic surfactant such as sodium lauryl sulfate. Preferably, the hydroxide ion is furnished by means of sodium hydroxide which also achieves the pH in the range of about 11 to about 13. It has critically been determined that the fractional steam distillation of benzaldehyde from the cinnamaldehyde must be conducted at a pH within the range of about 11 to about 13, preferably about 12 to about 12.5. Below and above this pH range, very poor conversions are obtained of 50% or far less and competing reactions interfere with the production of benzaldehyde. Outside of this critical pH range, side reactions, polymerization and other adverse reactions prohibit any significant yield of benzaldehyde. Yet, within the pH range of about 11 to about 13, especially about 12 to about 12.5, significant yields on the order of 75% or greater are achieved and benzaldehyde is recoverable in substantially pure form free of side reaction products. These results are considered to be unexpected especially at the high pHs of the reaction where it may have been expected that side reactions would have significantly lessened or prevented the yield for the desired product. During the course of the fractional steam distillation of benzaldehyde from the cinnamaldehyde, acetaldehyde is also vaporized and removed. The removal of acetaldehyde thus prevents the forward polymerization reaction which otherwise competes in the presence of the catalyst. The benzaldehyde which has been steam distilled is then subsequently fractionally distilled for separation of the benzaldehyde from other components in the distillate such as minor amounts of acetaldehyde, terpenes and orthomethoxybenzaldehyde. It has also been found that a natural source for the cinnamaldehyde such as cassia oil may be employed containing a substantial amount of the natural cinnamaldehyde. Thus, a natural product such as cassia oil may be employed in the fractional steam distillation method of this invention and still the significant yields on the order of about 75% or more are achieved. DETAILED DESCRIPTION The following detailed operating example illustrates the practice of the invention in its most preferred form, thereby enabling a person of ordinary skill in the art to practice the invention. The principles of this invention, its operating parameters and other obvious modifications thereof will be understood in view of the following detailed procedure. OPERATING EXAMPLE A solution was made up from 38.6 lbs. sodium hydroxide, 4 lbs. sodium lauryl sulfate and 10 liters antifoam agent in 760 gallons of water. The solution was stirred until a homogeneous solution was obtained. Then, 1320 lbs. of cassia oil were placed in a 1150 gallon still. The oil contained approximately 72% by weight of cinnamaldehyde. The still had a pot volume of about 1150 gallons onto which was mounted a 4 foot fractionating column containing 1".times.1" ceramic tubes and a water cooled condenser was thereafter connected in series for condensing the benzaldehyde-water azeotrope. The above prepared sodium hydroxide solution was then added to the cassia oil and introduced into the pot of the still. The pot was equipped with a stirrer. Using pressurized steam and vigorous stirring, the pot was heated to reflux with a pot temperature of 105.degree. C. Reflux was established with a column head temperature of about 99.degree. C. Once reflux was established, it was continued for about 1 hour. During the course of the conversion of the cinnamaldehyde in the cassia oil to benzaldehyde, pH was monitored and was maintained at about 12 to about 12.5. In the event the pH fell below about 12, sodium hydroxide was added to bring the pH back up to the range of about 12-12.5. After refluxing for about 1 hour, take-off of the water-benzaldehyde azeotrope was initiated. The water cooled condenser was operated at 100.degree. F. thereby enabling the water-benzaldehyde azeotrope to be condensed and collected in a chilled receiver. The acetaldehyde by-product was principally vaporized at the temperature of the condenser and was taken off as vapor. The distillate principally containing benzaldehyde in an amount of about 75% or more with minor amounts of cinnamaldehyde, terpenes, orthomethoxybenzaldehyde and acetaldehyde was obtained. The crude benzaldehyde was thus collected in a chilled receiver and, in a continuous feed operation the condensed water was continuously fed back to the still to replace what had been taken off and the distillation of the azeotrope continued. The fractional steam distillation of the crude benzaldehyde continued until about 670 lbs. of crude benzaldehyde were obtained. The crude distillate containing benzaldehyde was then dried under vacuum and fractionally distilled under vacuum of about 29" thereby providing a boiling point for the benzaldehyde at about 70.degree. C. in order to obtain a substantially pure benzaldehyde free from residual terpenes and other impurities. Thus, by means of practicing the above process, the objectives of this invention are achieved in that cinnamaldehyde is converted into benzaldehyde in substantially pure form even from the natural source of cassia oil. Surprisingly, it has been found that substantial yields in excess of 75% or more of substantially pure benzaldehyde are achieved by this method. Moreover, it has been found that there is a surprising window of high pH at which the conversion may take place in a fractional steam distillation column in order to separate the benzaldehyde and acetaldehyde from the reaction mixture and still avoid the adverse side reactions from occurring. Having described this invention and its operating parameters, variations may be achieved without departing from the spirit and scope hereof.
		psychokitty («») 10-11-04 06:45 No 535307				The surprises never end, do they? . . . (Rated as: good read)
						And here's yet another good and useful patent:  ( 1 of 1 ) United States Patent 4,766,249 Buck ,   et al. * August 23, 1988 Method of catalytically hydrolyzing alpha, beta-unsaturated carbonyl compounds Abstract Alpha, beta-unsaturated carbonyl compounds are hydrolyzed under alkaline conditions in the presence of water to produce additional carbonyl-containing compounds. High yields are obtained when the alkaline catalyst contains hydroxide ion and the pH is maintained in the range of about 11 to about 13. Inventors: Buck; Keith T. (Cincinnati, OH); Boeing; Anthony J. (Cincinnati, OH); Dolfini; Joseph E. (Cincinnati, OH); Glinka; Jerome (Cincinnati, OH) Assignee: Mallinckrodt, Inc. (St. Louis, MO) Notice: The portion of the term of this patent subsequent to June 16, 2004 has been disclaimed. Appl. No.: 942491 Filed: December 24, 1986 Current U.S. Class: 568/433; 568/458 Intern'l Class: C07C 045/42 Field of Search: 568/426,433,435,437,440,458 References Cited [Referenced By] Other References Guthrie et al., "Can. J. Chem.", vol. 62, pp. 1441-1445, (1984). Primary Examiner: Lone; Werren B. Attorney, Agent or Firm: Wood, Herron & Evans Parent Case Text RELATED APPLICATION This is a continuation-in-part of application Ser. No. 856,595, filed Apr. 25, 1986, invented by Keith T. Buck, Anthony J. Boeing and Joseph E. Dolfini, and assigned to the assignee of this application, now U.S. Pat. No. 4,673,766. Claims What is claimed is: 1. A method of producing a carbonyl-containing compound which comprises hydrolyzing by dispersing in water an alpha, beta-unsaturated carbonyl compound of the formula ##STR3## to produce a carbonyl-containing compound and by-product according to the following formulas ##STR4## wherein R' and R" are hydrogen, aliphatic or aromatic hydrocarbon groups or substituted derivatives thereof, and R"' is an aliphatic or aromatic aldehyde- or ketone-containing group having the carbon to oxygen double bond of said aldehyde or ketone conjugated with the alpha, beta double bond between C and R"' of alpha, beta-unsaturated alpha,beta-unsaturated carbonyl compound, and conducting said hydrolysis of the alpha, beta-unsaturated carbonyl compound under the action of heat in the presence of a catalytic amount of hydroxide ion and at a pH of about 11 to about 13. 2. The method of claim 1 which is conducted at a pH in the range of about 12 to about 12.5. 3. The method of claim 1 wherein the individual carbonyl-containing compounds obtained from said hydrolysis reaction are fractionally distilled for separation in substantially pure form. 4. The method of claim 1 conducted in the presence of an anionic or non-ionic surfactant. 5. The method of claim 1 conducted under shearing agitation to facilitate the dispersion of the alpha, beta-unsaturated carbonyl compound in the water. 6. The method of claim 1 wherein said alpha, beta-unsaturated carbonyl compound is citral and the carbonyl-containing compounds produced are 6-methyl-5-hepten-2-one and acetaldehyde. 7. The method of claim 1 wherein said alpha, beta-unsaturated carbonyl compound is pulegone and the carbonyl-containing compounds produced are acetone and 3-methylcyclohexanone. 8. A method of producing a carbonyl-containing compound which comprises hydrolyzing by dispersing in water under shearing agitation in the presence of an anionic surfactant an alpha, beta-unsaturated carbonyl compound of the formula ##STR5## to produce a carbonyl-containing compound and by-product according to the following formulas ##STR6## wherein R' and R" are hydrogen, aliphatic or aromatic hydrocarbon groups or substituted derivatives thereof, and R"' is an aliphatic or aromatic aldehyde- or ketone-containing group having the carbon to oxygen double bond of said aldehyde or ketone conjugated with the alpha, beta double bond between C and R"' of said alpha, beta-unsaturated carbonyl compound, and conducting said hydrolysis of the alpha, beta-unsaturated carbonyl compound under the action of heat in the presence of a catalytic amount of hydroxide ion and at a pH of about 12 to about 12.5. Description BACKGROUND OF THE INVENTION The retroaldol reaction of cinnamaldehyde is well known. In this reaction, cinnamaldehyde is converted to benzaldehyde and acetaldehyde with various potential side reactions. Recently, for example, an investigation of the kinetics of the retroaldol reaction of cinnamaldehyde has been reported by J. Peter Guthrie, et al, Can. J. Chem., Vol. 62, pp. 1441-1445 (1984). The conversion of the cinnamaldehyde to benzaldehyde has been long known and well studied. However, it has not been heretofore known to produce benzaldehyde from cinnamaldehyde in substantial yields, and favorable reaction conditions for production of such yields have not been reported. Similarly, citral has been hydrolyzed via the retroaldol reaction to produce 6-methyl-5-hepten-2-one and acetaldehyde. Again, however, product yield is low. Up to now, it has not been known how to obtain carbonyl-containing reaction products in substantial yields through the retroaldol hydrolysis of any of the alpha,beta-unsaturated carbonyl compounds, of which cinnamaldehyde and citral are examples. SUMMARY OF THE INVENTION The invention disclosed in the above application Ser. No. 856,595 is directed to a method of making benzaldehyde by conversion of cinnamaldehyde in the presence of water with surprisingly high yields heretofore unachieved. The invention involved the dispersion of cinnamaldehyde in water and, in the presence of an effective catalytic amount of hydroxide ion, fractionally steam distilling benzaldehyde from the cinnamaldehyde. The reaction was conducted at a pH on the order of about 11 to about B 13 and, unexpectedly, within this pH range it has been discovered that a substantial conversion of cinnamaldehyde to benzaldehyde could be achieved on the order of about 75% or more. It has also been found that the conversion may be achieved at such a high pH without adverse side reaction. It has also been found that members of the class of compounds known as alpha,beta-unsaturated carbonyl compounds, of which cinnamaldehyde is an example, can be hydrolyzed via the retroaldol reaction to produce carbonyl-containing compounds in substantial yields. In a preferred mode of conducting the method, the alpha,beta-unsaturated carbonyl compound is dispersed in water in the presence of shearing agitation. It will be understood that other water soluble or dispersible cosolvents such as alcohols, ethers or the like may be used in the aqueous reaction medium. An anionic surfactant such as sodium lauryl sulfate or a non-ionic surfactant such as polyethylene glycol having a molecular weight in the range of 400 to 600 may be used. Preferably, the hydroxide ion is furnished by means of sodium hydroxide which also achieves a pH in the range of about 11 to about 13. After the starting materials have been charged to the flask, reaction is initiated with the addition of heat. Once reaction has begun, separation of the products is achieved through the production of water-product azeotropes which are isolated by fractional distillation. It has been critically determined that the fractional distillation must be conducted at a pH within the range of about 11 to about 13, preferably about 12 to about 12.5. Reactions conducted outside this pH range exhibit very poor conversion to desired product because side reactions, polymerization and other adverse reactions occur. Reactions conducted within the pH range of about 11 to about 13, and especially between about 12 and about 12.5, produce significant yields on the order of 75% or greater and are substantially free of side reaction products. These results are considered to be unexpected especially at the high pH levels of the reaction where it may have been expected that side reactions would have significantly lessened or prevented the yield for the desired product. The reaction products isolated by fractional distillation may be further purified by means of additional separation techniques. The separation technique employed may vary with the degree of purity sought. Pure alpha,beta-unsaturated carbonyl compounds may be used as starting materials for the reaction. However, product yield percentage is not adversely affected when natural products containing the desired starting materials are used in the reaction. Thus, a natural product such as cassia oil containing substantial amounts of cinnamaldehyde may be used successfully in this invention. Similarly, lemon grass oil containing citral may be used successfully. Also, pennyroyal oil may be utilized under the teachings of this invention as a source of pulegone, an alpha,beta-unsaturated carbonyl compound. DETAILED DESCRIPTION The method in its broader aspects is practiced by hydrolyzing after dispersing in water an alpha,beta-unsaturated carbonyl compound having the formula ##STR1## to produce a carbonyl-containing compound and a by-product having the general formulas ##STR2## The substituents R' and R" are hydrogen, aliphatic or aromatic hydrocarbon groups or substituted derivatives thereof, and R"' is an aliphatic or aromatic aldehyde- or ketone-containing group having the carbon to oxygen double bond of the aldehyde or ketone conjugated with the alpha,beta double bond between C and R"' of the alpha,beta-unsaturated carbonyl compound. The hydrolysis reaction proceeds under the action of heat and is catalyzed by hydroxide ion having a concentration level sufficient to maintain the solution pH between about 11 and about 13. A large number of alpha,beta-unsaturated carbonyl compounds may be hydrolyzed according to the teachings of this invention. The compounds in the following non-comprehensive list are included under the description of hydrolyzable alpha,beta-unsaturated carbonyl compounds: cinnamaldehyde to produce benzaldehyde and acetaldehyde; citral to produce 6-methyl-5-hepten-2-one and acetaldehyde; pulegone to produce 3-methylcyclohexanone and acetone; 3-decen-2-one to produce heptanal and acetone; 2-dodecenal to produce decanal and acetaldehyde; 2-heptenal to produce pentanal and acetaldehyde; 2-hexenal to produce butanal and acetaldehyde; ionone to produce cyclocitral and acetone; irone to produce 2,5,6,6-tetramethyl-cyclohex-1-ene-1-carboxaldehyde and acetone; 1-(4-methoxyphenyl)-1-penten-3-one to produce paramethoxybenzaldehyde and methyl ethyl ketone; 5-methyl-3-hexen-2-one to produce isobutyraldehyde and acetone; alpha-methyl-iso-ionone to produce citral and methyl ethyl ketone; 5-methyl-2-phenyl-2-hexenal to produce phenyl acetaldehyde and 3-methylbutanal; 4-phenyl-3-buten-2-one to produce benzaldehyde and acetone; and ortho-methoxy cinnamaldehyde to produce ortho-methoxy benzaldehyde and acetaldehyde. (to be continued . . .)
		psychokitty («») 10-11-04 06:47 No 535308				Continued from above . . .
						OPERATING EXAMPLE I A solution was made up from 38.6 lbs. sodium hydroxide, 4 lbs. sodium lauryl sulfate and 10 liters antifoam agent in 760 gallons of water. The solution was stirred until a homogeneous solution was obtained. Then, 1320 lbs. of cassia oil were placed in a 1150 gallon still. The oil contained approximately 72% by weight of cinnamaldehyde. The still had a pot volume of about 1150 gallons onto which was mounted a 4 foot fractionating column containing 1".times.1" ceramic tubes and a water-cooled condenser was thereafter connected in series for condensing the benzaldehyde-water azeotrope. The above prepared sodium hydroxide solution was then added to the cassia oil and introduced into the pot of the still. The pot was equipped with a stirrer. Using pressurized steam and vigorous stirring, the pot was heated to reflux with a pot temperature of 105.degree. C. Reflux was established with a column head temperature of about 99.degree. C. Once reflux was established, it was continued for about 1 hour. During the course of the conversion of the cinnamaldehyde in the cassia oil to benzaldehyde, pH was monitored and was maintained at about 12 to about 12.5. In the event the pH fell below about 12, sodium hydroxide was added to bring the pH back up to the range of about 12-12.5. After refluxing for about 1 hour, take-off of the water-benzaldehyde azeotrope was initiated. The water-cooled condenser was operated at 100.degree. F. thereby enabling the water-benzaldehyde azeotrope to be condensed and collected in a chilled receiver. The acetaldehyde by-product was principally vaporized at the temperature of the condenser and was taken off as vapor. The distillate consisted principally of benzaldehyde in an amount of about 75% or more with minor amounts of cinnamaldehyde, terpenes, orthomethoxybenzaldehyde and acetaldehyde. The crude benzaldehyde was thus collected in a chilled receiver and, in a continuous feed operation the condensed water was continuously fed back to the still to replace what had been taken off and the distillation of the azeotrope continued. The fractional steam distillation of the crude benzaldehyde continued until about 670 lbs. of crude benzaldehyde was obtained. The crude distillate containing benzaldehyde was then dried under vacuum and fractionally distilled under vacuum of about 29" thereby providing a boiling point for the benzaldehyde at about 70.degree. C. in order to obtain a substantially pure benzaldehyde free from residual terpenes and other impurities. OPERATING EXAMPLE II Into a 5-liter, 3-neck flask was charged 1012.5 g of pennyroyal oil, containing a substantial portion of pulegone, 3.5 liters water and 30 g sodium hydroxide having a minimum 90% purity. The initial charge of hydroxide produced a pH of about 12. The pH was monitored during the subsequent reaction, and additional sodium hydroxide was added as needed to maintain a pH of about 12. The flask was equipped with a mechanical stirrer/drive motor apparatus and a fractionating column. After agitation was initiated, heat was applied to the mixture in the flask by means of a heating mantle. As the agitated mixture of pennyroyal oil, sodium hydroxide and water was heated, the pressure in the flask was maintained at atmospheric by permitting the fractionating column to remain uncapped. At a pot temperature of approximately 100.degree. C. and a head temperature of approximately 56.degree. C., distillation occurs and an azeotropic mixture of 96% acetone and 4% water is collected off the top of the fractionating column. The azeotrope was collected by means of the fractionating column. The co-distillation of acetone occurred over a period of about six days. Agitation and heating were discontinued when no additional distillate was generated. The oil layer remaining in the flask was separated from the sodium hydroxide solution and then water-washed to remove traces of sodium hydroxide. The washed oil contained the hydrolysis product 3-methylcyclohexanone (b.p. 168.degree.-9.degree. C.), minor amounts of unhydrolyzed pulegone (b.p. 224.degree. C.), and other trace components attributable to the starting pennyroyal oil. The acetone was subsequently assayed for purity, including a determination of water content. The yield of acetone was approximately 73%. OPERATING EXAMPLE III Approximately 500 ml water, 5 g (90% active) sodium hydroxide, and 88 g terpeneless lemon grass oil containing approximately 95% citral were charged into a one-liter round bottom flask. The round bottom flask was equipped additionally with a trap having means of permitting removal of the lower density liquid while recirculating the higher density liquid, a fractionating column, and a means for stirring. The stirred contents of the flask were heated to reflux by means of a heating mantle. The pH of the contents was set at 12 and maintained at that level during the remainder of the run by addition of sodium hydroxide when necessary. The contents were refluxed for one hour, after which time the steam distillate was slowly collected. The distillate take-off was regulated so that little or no citral distilled over. The distillation was continued until no additional oil was collected. The oil phase distillate was separated from the steam condensate. The separated oil was then short-path vacuum distilled. The main cut yielded 72 g of the citral hydrolysis product, 6-methyl-5-hepten-2-one. The other reaction product, acetaldehyde, was vented from the flask through the fractionating column during the reaction. The yield of 6-methyl-5-hepten-2-one was approximately 90% under the above conditions. Thus, by means of practicing the preferred processes listed above, the objectives of this invention are achieved in that desirable products can be obtained in good yield from alpha,beta-unsaturated carbonyl compounds. Pure starting materials may be used, but good results are obtainable even from natural sources of the alpha,beta-unsaturated carbonyl compounds. It is critical to the teachings of this invention that reaction take place in an alkaline hydroxide environment wherein the pH is maintained within a window of about 11 to about 13. Unexpectedly, not only are products obtained in yields exceeding 70 to 75%, but the reaction proceeds with a low level of competitive side reactions, polymerization or other adverse reactions. Having described this invention and its operating parameters, variations may be achieved without departing from the spirit and scope hereof.
		psychokitty («») 10-11-04 23:05 No 535419				Another retroaldol cleavage of cinnamaldehyde? (Rated as: good read)
						Here's another way to get benzaldehyde using a variation of the retroaldol reaction.  4-Phenyl-3-buten-2-one is oxidized to the epoxide via basic H2O2 and then cleaved by the NaOH to benzaldehyde and acetone.  The yields are supposedly higher that the then-utilized base-catalyzed "retrograde aldol reaction" (retroaldol reaction) and the products of the reaction appear to be cleaner.  All in all, the method seems pretty simple and just as OTC as the aforementioned retroaldol reaction using cinnamaldehyde as a precursor to benzaldehyde. The Epoxidation and Cleavage of a,B-Unsaturated Ketones with Alkaline Hydrogen Peroxide ROBERT D. TEMPLE The Journal of Organic Chemistry Vol. 35, No. 6, May 1970 Abstract: The kinetics of the reaction between 4-phenyl-3-buten-2-one and aqueous alkaline hydrogen peroxide were studied. Four reactions occur in this system : epoxidation by hydroperoxide ion to form 4-phenyl-3,4-epoxy-2-butanone, oxidative cleavage of the epoxide by hydroperoxide to give benzaldehyde, retrograde aldol reaction,and cleavage of the epoxide by hydroxide. The rates of these reactions in water at 25” are 0.22,0.05,0.00016,and 0.0032 1. mol-’ sec-l, respectively. The influence of substituents in the phenyl ring on reaction rates and the relative reactivities of hydroperoxide and hydroxide ions are discussed in terms of the reaction mechanisms. The oxidative cleavage of a,p-epoxy ketones is mechanistically similar to several recently reported fragmentation reactions. The cleavage reaction was shown to have general synthetic utility in preparing diacids, keto acids, and ketones from +-unsaturated ketones, alp-unsaturated aldehydes, and p diketones. Preparative Oxidation Procedure: To a solution of 0.01 mol of the a,B-unsaturated carbonyl compound in 50 ml of methanol,12 ml of 30% aqueous hydrogen peroxide and then 30 ml of 1 N aqueous sodium hydroxide solution were added with cooling. The mixture was then stirred overnight at 40-50" (1 hr at 40" for the reaction with citral). The resulting solution was evaporated to about half the original volume on a rotary evaporator and then washed with ether. The aqueous solution was made acidic with sulfuric acid, saturated with sodium sulfate, and extracted thoroughly with ether. The extract was treated with FeSO4 or Na2SO3 to destroy peroxides, dried (MgSO4), and evaporated. The residue, which was essentially pure product, was recrystallized, distilled, or converted into a suitable derivative as outlined below. Note:  4-Phenyl-3-buten-2-one is not listed in the experimetal section of the article.
		psychokitty («») 10-12-04 00:11 No 535428				Baeyer-Villiger reaction using Oxone as oxidant (Rated as: excellent)
						Maybe this might work to effect a more OTC Baeyer-Villiger transformation. Facile Oxidation of Aldehydes to Acids and Esters with Oxone Benjamin R. Travis, Meenakshi Sivakumar, G. Olatunji Hollist, and Babak Borhan* ORGANIC LETTERS 2003 Vol. 5, No. 7 1031-1034 Abstract: A highly efficient, mild, and simple protocol is presented for the oxidation of aldehydes to carboxylic acids utilizing Oxone as the sole oxidant. Direct conversion of aldehydes in alcoholic solvents to their corresponding ester products is also reported. These reactions may prove to be valuable alternatives to traditional metal-mediated oxidations. Description of the art: As a fortuitous extension of the solvent study, the  oxidation of aldehydes with Oxone in alcoholic solvents cleanly provided high conversion to esters. Thus, the oxidation of benzaldehyde in methanol did not yield the expected carboxylic acid, but instead the methyl ester was obtained. The present strategy complements other known methods that directly convert aldehydes to esters such as oxidation in the presence of alcohol with Br2 or I2, NBS/AIBN, PDC, HCN/MnO2, or performed  electrochemically.21-25 Additionally, we found that other alcohols such as ethanol, n-propanol, and 2-propanol also provide their corresponding esters in excellent yields, although oxidation in tert-butyl alcohol furnished the carboxylic acid as the sole product (Table 3, entries 1-9). It is important to note that the esters are not obtained as the result of the oxidation of aldehydes to carboxylic acids followed by Fischer-type esterification of the acids in alcoholic solvents. Incubation of benzoic acid in methanol with Oxone for a prolonged period did not result in the isolation of methyl benzoate, but in fact the starting acid was re-isolated quantitatively. The direct oxidation of a variety of aryl and alkyl aldehydes to their corresponding methyl esters is also illustrated in Table 3 (entries 10-19). Oxidation of aryl aldehydes with electron-withdrawing substituents showed slow conversion to the esters (Table 3, entries 10 and 11) initially providing dimethyl acetals in addition to the ester products. This was overcome by heating the reactions to reflux overnight, which provided clean conversion to the  desired methyl esters 1b and 2b. Oxidation of 6 and 9 (electroneutral aromatics aldehydes) and 19-23 (aliphatic aldehydes) proceeded smoothly at rt to furnish the desired methyl esters in excellent yields. In the case of electronrich aromatic substrates, as with the oxidations to carboxylic acids in DMF, the Dakin products were observed. thus, 4-hydroxybenzaldehyde, 12, and p-anisaldehyde, 13, provided primarily phenols 16 and 17 in 77% yield for both (Scheme 3), along with small amounts of the corresponding  sters (Table 3, entries 14 and 15). Additionally, oxidation of 27 provided 75% yield of the з-ketomethyl ester product 30 (methyl ester of 29). Noteworthy, is the fact that isopropyl esters are made with ease in high yields. However, as mentioned above, tert-butyl esters cannot be accessed, most probably due to the sterics of the bulky alcohol. Although at this time conversion of aldehydes to esters proceed best if the reaction is  performed in the alcoholic solvent (in order to circumvent the formation of carboxylic acids), studies are underway  with mixed solvents and show promising indications that the oxidation to carboxylic acids could be retarded in favor of esterification. Thus, it could be possible to lessen the  amounts of alcohol used in the oxidation.   Although any mechanistic discussion is speculative at this point, we believe that the oxidation proceeds via a Baeyer-Villiger process. As depicted in Scheme 4, the proposed intermediates in the oxidation of aldehydes to carboxylic acids and esters are mixed peroxyacetals A and B. Rearrangement of intermediates A and B would yield the  products by expelling bisulfate. Corroboration for the proposed mechanism is based on the well-understood oxidation of aldehydes to carboxylic acids with peroxyacids.26 Also, recently it has been demonstrated that acetals are oxidized to their corresponding esters with Oxone,10 and thus, intermediate B could be derived from either the hemiacetal or acetal (Scheme 4). It should be pointed out that Oxone is slightly acidic and, therefore, could catalyze the formation of the presumed peroxyacetals. Presently, mechanistic studies including use of 18O-labeled aldehydes and NMR experiments to observe transient intermediates are underway. In conclusion, we have demonstrated a simple and effective one-pot protocol to oxidize aldehydes directly to acids or esters. These reactions are facile, high-yielding, and easy to work up (most do not require chromatography) and should provide a mild oxidative alternative for organic chemists. The mechanism of these transformations is being investigated and will be reported in due course. Experimental:  (A bit too simple.) Aldehyde (1 equiv), Oxone (1 equiv), ROH (0.2 M), 18 h, rt.
		bio (Hive Bee) 10-12-04 06:37 No 535485				Baeyer-Villiger reaction recycling
						Some nice articles you found psychokitty. Assuming you have a basic understanding of the procedure of this thread (Rhodium posted some dwgs somewhere) I wanted to ask you if you have any input on the following: In the patent twodogs cited where he got the idea of using perborate it states ......(paraphrased)near quantitative yields of the B/V product can be achieved in the oxidation by appropriate recycling.......... That's it no experimental, examples, discussion, nothing. Will be making a few more runs with the MePhBuO soon and will try  some recycling ideas at small test scale. Ah.... so many reactions so little time... Now I suppose that the simplest and easiest way to do this would be to simply filter, add more perborate and run it again. Maybe removing some water (dessicant) would be helpful. Hopefully the selectivity is such that the ketone enol ester would not be damaged. Another place would be after the isolation before the hydrolysis or even after the hydrolysis itself. Any thoughts on this?????? I have various improvements on the overall procedure but nobody seems to be interested enough in this method (except one bee I know of) to actually do it. So I don't waste my time but I do thank you and the Hive for all the great stuff, especially Rhodium for finding several of the key references for this and similar reactions.
		psychokitty («») 10-13-04 05:28 No 535611				United States Patent 4,988,825
						In the patent twodogs cited where he got the idea of using perborate it states ......(paraphrased)near quantitative yields of the B/V product can be achieved in the oxidation by appropriate recycling.......... That's it no experimental, examples, discussion, nothing. Will be making a few more runs with the MePhBuO soon and will try  some recycling ideas at small test scale. Ah.... so many reactions so little time... Actually, the segment in the patent to which you refer goes like this: The present invention provides a safe and economical process for oxidizing aldehydes and ketones using an alkali metal perborate, such as sodium perborate, as the oxidant. Alkali metal perborates are safe and economical to use, and the sodium borate by-product thus formed is safely handled and is a valuable product that can be sold in its own right. In addition, the oxidation is carried out under easily maintained reaction conditions and provides selectivities approaching 100% so that all of the starting aldehydes or ketones can be converted to final product by appropriate recycling. It can be seen that the use of the alkali metal perborate provides a substantial advance in the oxidation of aldehydes and ketones. All the authors are trying to say is that because the use of sodium perborate is so exceptionally selective, there won't be any byproducts to the reaction, and whatever starting materials are left over--in this case, the intermediate aldol condensation product of benzaldhyde and MEK--can be reused in another sodium perborate Baeyer-Villiger reaction. Anyway, that's my interpretation.  I could be wrong. Here's the a text copy of the patent in question, for all those who would like to read it: ( 1 of 1 ) United States Patent 4,988,825 Bove January 29, 1991 Oxidation of aldehydes and ketones using alkali metal perborates Abstract Aldehydes and ketones, other than acetone, are oxidized with an alkali metal perborate in the presence of an acid. Inventors: Bove; John L. (Ridgewood, NJ) Assignee: Cooper Union Research Foundation, Inc. (New York, NY) Appl. No.: 910615 Filed: September 23, 1986 Current U.S. Class: 549/272; 549/273; 549/295; 560/231; 562/528 Intern'l Class: C07D 313/18; C07D 313/04 Field of Search: 549/272,273,295 562/528 560/231 References Cited [Referenced By] U.S. Patent Documents 3122586 Feb., 1964 Berndt et al. 3154586 Oct., 1964 Bander et al. 3483222 Dec., 1969 Sennewald et al. 3716563 Feb., 1973 Brunie et al. 549/524. 3833613 Sep., 1974 Field 549/272. 4160769 Jul., 1979 Higley. 4213906 Jul., 1980 Mares et al. 549/272. 4286068 Aug., 1981 Mares et al. 549/272. 4338260 Jul., 1982 Schirmann 260/502. Foreign Patent Documents 1096967 Dec., 1967 GB 549/272. Other References Y. Ogata et al., Bulletin of the Chemical Society of Japan, vol. 52(2), (1979), pp. 635-636. A. Baeyer et al., Ber., 1899, 32, 3625-3633. A. Baeyer et al., Ber., 1900, 33, 858-864. Ogata et al., Chem. Abst. 90:167685, (1979). McKillop et al., Tetrahedron Letters, 24, No. 14, (1983), 1505-1508. McKillop et al., Tetrahedron, 43, pp. 1753-1758 (1987). A. Rashid et al., J. Chem. Soc. (C) (1967), pp. 1323-1325. Description The present invention is directed to the oxidation of aldehydes and ketones to the corresponding acids and esters, respectively using an alkali metal perborate as the oxidant. The oxidation of ketones, including cyclic ketones, to esters through the use of peracids is known as the Baeyer-Villager Reaction (A. Von Baeyer and V. Villager, Ber., 1899, 32, 3265; 1900, 33, 858) While widely applied, particularly for the oxidation of cyclohexanone to epsilon-caprolactone, nevertheless the use of a peracid presents problems of safety and disposal and/or recycling of organic compounds. The present invention provides a safe and economical process for oxidizing aldehydes and ketones using an alkali metal perborate, such as sodium perborate, as the oxidant. Alkali metal perborates are safe and economical to use, and the sodium borate by-product thus formed is safely handled and is a valuable product that can be sold in its own right. In addition, the oxidation is carried out under easily maintained reaction conditions and provides selectivities approaching 100% so that all of the starting aldehydes or ketones can be converted to final product by appropriate recycling. It can be seen that the use of the alkali metal perborate provides a substantial advance in the oxidation of aldehydes and ketones. In particular, the present invention provides a method of preparing acids or esters, which comprises oxidizing an aldehyde (other than acetone) or a ketone with an alkali metal perborate in the presence of an acid. With the exception of acetone, the present invention is applicable to the oxidation of aldehydes and ketones to form the corresponding esters and/or acids. Aromatic and aliphatic aldehydes and ketones may be used, such as benzaldehyde and methylethyl ketone and the like, as well as cyclic ketones, such as cyclohexanone and the like. Aliphatic and cycloaliphatic aldehydes and ketones containing olefinic unsaturation may likewise be employed to form the corresponding unsaturated ester and/or acid. When ketones are oxidized according to the present invention, the product obtained will be the corresponding ester, but in some cases a mixture of the ester and acid will be produced. In a preferred embodiment, the present invention may be used for the preparation of esters and/or acids of the formula (I) ##STR1## which comprises reacting an aldehyde or ketone of the formula (II) ##STR2## wherein R.sup.1 is alkyl or aryl, R.sup.2 is hydrogen, alkyl or aryl, or R.sup.1 and R.sup.2 are both hydrogen, or R.sup.1 and R.sup.2 together represent alkylene, provided that R.sup.1 and R.sup.2 may not both be methyl. When R.sup.1 and R.sup.2 is alkyl, R.sup.1 and R.sup.2 may be straight or branched chain alkyl, suitably straight or branched chain alkyl of from 1 to about 15 carbon atoms, such as from 1 to about 10 carbon atoms. When R.sup.1 or R.sup.2 is aryl, R.sup.1 and R.sup.2 may be aryl of from 1 to about 4 rings, including fused rings, and may suitably contain from about 6 to about 30 carbon atoms. Suitably, R.sup.1 or R.sup.2 maybe phenyl, naphthyl, biphenyl and the like. When R.sup.1 and R.sup.2 together represent alkylene, the alkylene may suitably be straight or branched chain alkylene of from about 1 to about 15 carbon atoms in the carbon-to-carbon chain, such as from 1 to about 10 carbon atoms in the carbon-to-carbon chain. Usually when R.sup.1 and R.sup.2 together represent alkylene, there will be from about 1 to about 30 carbon atoms in total, preferably from about 3 to about 15 carbon atoms in total. In the above formulas (I) and (II), alkyl and alkylene may be unsubstituted or substituted by aryl, halogen, nitro or the like, while the aryl may be substituted by alkyl, preferably lower alkyl, i.e. from about 1 to about 6 carbon atoms, halogen, nitro or the like. Preferably, R.sup.1 may represent alkyl of from about 1 to about 10 carbon atoms, phenyl, or alkylene of from about 3 to about 15 carbon atoms with from about 3 to about 9 carbon atoms in the carbon-to-carbon chain, said alkyl, phenyl or alkylene being unsubstituted or substituted by halogen, cyano or nitro or, in the case of phenyl, lower alkyl. Further, R.sup.2, or both R.sup.1 and R.sup.2 may represent hydrogen. While sodium perborate tetrahydrate will normally be used, both in terms of economy and convenience, other alkali metal perborates may be employed of the formula (III) MBO.sub.3.nH.sub.2 O (III) wherein M is an alkali metal, preferably sodium or potassium, and n is 1 to 4, usually 4. Suitably, the oxidation is carried out with the perborate (III) in the presence of an acid that hydrolyzes in water to form hydronium ions, such as mineral acids, sulfonic acids, organic acids, and the like, but a Lowry-Bronsted acid or Lewis acid may also be used, such as BF.sub.3. Glacial acetic acid is safe and economical and hence is presently preferred. Other useful organic acids include trifluoroacetic acid and formic acid. When an organic acid is employed, it may also serve as a solvent. If a solvent or co-solvent is required, any suitable inert solvent may be employed, such as acetone, halogenated hydrocarbons, such as methylene chloride, chloroform and the like, aliphatic and aromatic esters, benzene and the like. It is noted that acetone, while a ketone, is nevertheless not oxidized by the perborate (III) and hence may be used as a solvent, if desired. Usually, the oxidation will be initiated at a temperature of from about 30.degree. to about 70.degree. C., usually from about 40 to about 60.degree. C. While lower temperatures can be used, reaction rates will necessarily be slower. Temperatures higher than about 70.degree. C. may be used, if required or desired, depending upon the desired reaction rate. However, the reaction is exothermic and hence external cooling may be needed to control the reaction temperature, even at the lower temperatures employed. The present invention is illustrated in terms of its preferred embodiments in the following Examples. In this specification and the appended claims, all parts and percentages are by weight, unless otherwise stated. EXAMPLE 1 Preparation Of Epsilon-Caprolactone To a 200 ml roundbottom flask was added 4.9 grams (0.05 mole) of cyclohexanone, 50ml of glacial acetic acid, and 11.4 grams (0.075 mole) of sodium perborate tetrahydrate. The mixture was heated to 50.degree. C. using a water bath. The reaction temperature was maintained in the range of 50-55.degree. C., while stirring the mixture with a magnetic stirrer for four hours, after which the reaction mixture was cooled to room temperature, and the solid sodium borate was separated from the mixture using section filtration. The acetic acid was stripped from the remaining liquid residue using a rotary evaporator, and the remaining epsilon-caprolactone was purified by vacuum distillation. Yield: 91% theoretical. EXAMPLE 2 Preparation of Benzoic Acid The procedure of Example 1 was followed using 5.3 grams (0.05 mole) of benzaldehyde as the starting material. Crude benzoic acid formed was purified by recrystallization. Yield: about 50% theoretical. EXAMPLES 3-6 Following the procedure of Example 1, the ketones set forth below were oxidized with sodium perborate at a temperature of about 55.degree. C. to provide the esters and acid set forth in Table 1 below.                   TABLE 1     ______________________________________     Example            Starting Material                         End Product      Yield     ______________________________________             ##STR3##                          ##STR4##        75%     4             ##STR5##                          ##STR6##        74%     5             ##STR7##                          ##STR8##        68%     6             ##STR9##                          ##STR10##       24%                         HOOC(CH.sub.2).sub.5COOH                                          38% The most current patent detailing this reaction process, which has links to the relevant patent history of the prior art, is as follows: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=/netahtml/search-bool.html&r=2&f=G&l=50&co1=AND&d=ptxt&s1=%27sodium+perborate%27&s2=Baeyer-Villiger&OS=%22sodium+perborate%22+AND+Baeyer-Villiger&RS=%22sodium+perborate%22+AND+Baeyer-Villiger
		psychokitty («») 10-13-04 07:35 No 535629				Methyl-(a-alkyl-)-styryl ketones (Rated as: good read)
						Information in this post relevant to this thread taken from the PDF documents found in Post 531053 (psychokitty: "Propenylbenzenes anyone?", Chemistry Discourse): SOME ALPHA-ALKYLCINNAMIC ACIDS AND THEIR DERIVATIVES BY MARSTON TAYLOR BOGERT AND DAVID DAVIDSON J.A.C.S. v. 54 pp.334-338 (1939) The phenomenal success of a-amylcinnamic aldehyde and other a-alkylcinnamic aldehydes as perfume bases, led us to prepare several of the corresponding methyl ketones (methyl- (a-alkyl-)-styryl ketones) (111). These were synthesized by condensing benzaldehyde with alkyl acetones (11) by means of hydrogen chloride. . . . . . . Ethyl, n-propyl, n-butyl and n-amyl derivatives are reported in this paper. The attempt to prepare the isopropyl derivatives by starting with isopropyl acetone, (CH3)2CHCH2COCH3, gave an anomalous result, since it was not found possible to prepare a solid oxime from the supposed methyl (a-isopropyl-)-styryl ketone, nor to oxidize it to a-isopropylcinnamic acid. . . . Experimental: One-half mole of benzaldehyde was mixed with one mole of the alkyl acetone and one-fourth mole of hydrogen chloride gas passed into the cooled mixture. The mixture, which soon became red, was then shaken for sixteen to twenty hours. At the end of this time the water formed in the reaction had separated as aqueous hydrochloric acid and was removed. Without further treatment, the oil was distilled under diminished pressure (about 20 mm.). Somewhat more than half of the alkyl acetone was recovered and a small residue, probably consisting of dibenzal-alkyl acetone (styryl-( a-alkyl-)- styryl ketone), remained in the flask. The principal fraction, consisting of crude methyl (a-alkyl-)-styryl ketone, was obtained in a yield of about 90% based on the alkyl acetone consumed, or about 75% based on the benzaldehyde employed. The crude alkyl acetone fraction was treated with one-half mole of benzaldehyde and sufficient alkyl acetone to replace that consumed in the first reaction. Hydrogen chloride was then added and the reaction carried out as before. The process was repeated three times but could probably be carried on indefinitely. By using two moles of alkyl acetone to one of benzaldehyde and reworking the recovered alkyl acetone in this way, the amount of dibenzal derivative formed was greatly reduced, with consequent improvement in the yield of the desired product. The crude methyl (a-alkyl-)-styryl ketone may be used directly for the preparation of the a-alkylcinnamic acids. To purify it, the crude product was washed with saturated sodium bisulfite, followed by water and then treated with alcoholic potassium hydroxide, thrown into water, acidified with acetic acid, extracted with benzene, dried over sodium sulfate and distilled. A middle fraction was taken for analysis. The methyl (a-alkyl-)-styryl ketones are liquids having a greenish-yellow tinge, with a floral odor which resembles, but is much weaker than, that of the a-alkylcinnamic aldehydes. Physiologically Active Phenethylamines. I. Hydroxy- and Methoxy-alpha-methyl-beta-Phenethylamines (beta-Phenylisopropylamines) E. H. WOODRUFF AND THEODORE W. CONGER J.A.C.S. Feb 1938 v. 60 pp. 465-467 . . . An excellent preparation for a-alkylcinnamic acids is that recently carried out by Bogert and Davidson" who oxidized with hypohalite methyl (a-alkyl styryl) ketones prepared by condensing benzaldehyde with a methyl alkyl ketone in the presence of dry hydrogen chloride gas. With modification this was found to give excellent yields of the methoxy-a-methylcinnamic acids The other steps in the synthesis follow essentially experimental procedures already appearing in the literature. . . . . . . When condensing the methoxy aldehydes with methyl ethyl ketone it was necessary to cool the aldehyde-ketone mixture in an ice salt bath during the addition of the hydrogen chloride gas and to allow the reaction to proceed in an electric refrigerator at 0-5 °C or in the freezing chamber at -10 to -5 °C for twenty-four to forty-eight hours, instead of at room temperature. It was found further that a practical grade of methyl ethyl ketone could be used. In this case instead of recovering the unused ketone the reaction mixture was taken up in ether, neutralized with solid sodium carbonate and washed thoroughly with water before drying with anhydrous magnesium sulfate and distilling. These changes were found to be of particular value in the case of the m-methoxy compound.
		psychokitty («») 10-13-04 08:55 No 535634				Two great articles (Rated as: excellent)
						100 Years of Baeyer-Villiger Oxidations Michael Renz, Bernard Meunier European Journal of Organic Chemistry Volume 1999, Issue 4 , Pages 737 - 750 Abstract: In the present review, we report the discovery of the formation of esters and lactones by oxidation of ketones  with a peroxide derivative, namely the Baeyer-Villiger reaction. This reaction was first reported by Adolf von Baeyer and Victor Villiger a century ago in 1899, just one year after the oxidant they used (KHSO5) has been described. Furthermore, Baeyer and Villiger established the composition of this new inorganic peroxide and showed that its instability was the reason of a controversy between several European chemists between 1878 and 1893. For the first 50 years the mechanism of the Baeyer-Villiger reaction was a matter of debate. A side product, 1,2,4,5-tetraoxocyclohexane, was ruled out as an intermediate in the ester formation by Dilthey. Criegee postulated a nucleophilic attack of the oxidant on the carbonyl group. This mechanism was confirmed by von E. Doering by a labeling experiment with [18O]benzophenone. The rearrangement step occurs with retention of the stereochemistry at the migrating center. The competitive migration and the rate-determining step are also discussed in this review. Chemistry: How green was my ester GIORGIO STRUKUL Nature 412, 388 - 389 (26 July 2001); DOI:doi:10.1038/35086670 Introduction: Hydrogen peroxide is an ideal oxidant. It cannot yet be used widely, because viable catalysts aren't available for many industrially important processes. But there are encouraging indications of progress. Chemistry has turned green. The increased awareness of  environmental problems has generated an overly simplistic division, however, especially in the media, between ‘bad’  chemistry — which first pollutes and then (sometimes) cleans up — and ‘good’, green chemistry. Chemists themselves are partly responsible for setting up this misleading contrast. But they are nonetheless among the leaders in trying to find less wasteful or damaging ways to handle the planet’s resources.
		bio (Hive Bee) 10-14-04 04:05 No 535753				B/V recycling
						Another good batch of reading material you found, psychokitty. I have been intending to try the "distill direct" method for the MePhBuO, after mechanical HCl removal, from the article you posted.  Also extracting with PhMe or Hexane from the start helps minimize emulsions and the washings go fast. But why even wash if it's not needed. I've gone straight to the oxidation w/o crystallizing (fractionate only) but yields suffered somewhat. You can crystallize w/o distilling with good results but it is much easier and faster to just distill it.  Also it does help to keep the condensation mixture cold to avoid tar formation and process it right away if it sets solid faster than usual. Had one batch setup in 6 hours (11 hours from gassing). Regarding your statement............... All the authors are trying to say is that because the use of sodium perborate is so exceptionally selective, there won't be any byproducts to the reaction, and whatever starting materials are left over--in this case, the intermediate aldol condensation product of benzaldhyde and MEK--can be reused in another sodium perborate Baeyer-Villiger reaction................ Yes, this is also my understanding. My request for suggestions was >>>>>WHERE>>>>>> do you think would be the best place in the procedure? The unreacted unsaturated ketone could be isolated before the hydrolysis step in pure form by fractionating, but perhaps this would not be necessary. The ester made it through once (the oxidation) why not just run it again. Water removal might be the sticking point here though. Ever wonder why they call them LABORatories? I think you know what I mean. Not enough hours in the day,  without the technicians and assistants, to do it all.
		Mendeleev (Stranger) 10-27-04 03:05 No 538031				how about replacing the perborate with percarbonat
						Sodium percarbonate has been known to form peracids as well: Post 415088 (GC_MS: "The synthesis of peracids", Chemistry Discourse)      However there are few details in this post.  Could you use percarbonate instead of the perborate?  Not that obtaining sodium perborate is difficult, it's just that sodium percarbonate happens to be OTC and obscenely cheap. Trogdor was a man.  A dragon man.  Or maybe just a dragon...
		bio (Hive Bee) 10-27-04 08:30 No 538078				Na Percarbonate
						The percarbonate should also work but I would suggest perhaps keeping the active O2 content equal or better than the perbotate and any hydrated or insipient water to a minimum. The reaction conditions are somewhat different though. See the Percarbonate/Perborate review article on Rhodiums site. It offers many references and insights, one of which is that the perborate tetrahydrate is just as effective as the monohydrate, which is unexpected, and suggests a reaction mechanism which is only postulated. The percarbonate I saw in the store was only 10% and would surely be a real pain in the ass to separate from all the other crap. Most dry bleaches have one or the other. Never checked but the straight stuff may be available at industrial cleaning suppliers. I just can't see spending days to separate a little from soap powder etc. that is so cheap and easily available as perborate although the percarbonate is cheaper. If, for whatever reason, you must make or extract the stuff OTC I would suggest just getting borax and H2O2 as being much easier and the product would be clean and fresh. Sounds like a soap commercial, lol.
		psychokitty («») 10-28-04 03:12 No 538243				The temperature of the reaction may be the problem
						If the temperature of the perborate reaction--forming, as I understand it, peracetic acid in situ--is above 30°C, that may in fact be the problem with the low 35% yields as the peracetic acid oxidation of 2-acetyl-propenylbenzene is recommended to take place well below that temperature. For example:  https://www.rhodium.ws/chemistry/dillapiole.analogs.html This compound was quantitatively methylated to 9 in preparation for the Baeyer-Villiger and subsequent hydrolysis of the formate ester to form 10. The conversion of 9 to 10 was carried out using 1 equiv. of MCPBA in CHCl3 at 0°C for 18 h and afforded the formyl intermediate in 71% isolated yield, saponification of which gave 10. Under these conditions competition by the alkene moiety for the peracid to give an epoxide was minor; at room temperature the rates of desired Baeyer-Villiger and the epoxidation were quite comparable. Finally, methylation of 10 with CH3I-K2CO3 in acetone afforded pure dillapiol. For the buffered peracetic acid reaction as per Chromic's instruction, see all the relevant posts in the following thread: Post 250788 (Chromic: "Peracetic in DCM - dreams of success", Methods Discourse) For an example of the diluted buffered peracetic acid Baeyer-Villiger oxidation of a,B-unsaturated ketones, see the following thread (EDIT; SORRY MOO!): Post 504867 (moo: "Baeyer-Villiger on unsaturated ketones", Novel Discourse) Can anybee speak french?  I wonder what the exact details are to the 1936 french article listed in Post 487934 (Rhodium: "Peracid oxidation of unsaturated ketones", Novel Discourse) Also, using aqueous HCl might be a better way to carry out the hydrolysis of the phenylacetone enol acetate as use of aqueous NaOH may be contributing to the polymerization of the final product.  For more details about NaOH polymerization, see Post 336996 (Rhodium: "Base-catalyzed polymerization of P2P", Chemistry Discourse); for an example of HCl hydrolysis, see Post 476334 (Chromic: "HCl is so good it's GOLDEN!", Chemistry Discourse). It would appear that the advantages to the peracid oxidation of alkenes to epoxides or diols is comparable to the peracid oxidation of a,B-unsaturated ketones to enol esters. I'll bee back soon with more information.
		moo (Hive Addict) 10-28-04 16:36 No 538339				Posted already. Post 504867
						Posted already, also see Rhodium's reply on the subject. Post 504867 (moo: "Baeyer-Villiger on unsaturated ketones", Novel Discourse) fear fear hate hate
		bio (Hive Bee) 10-29-04 11:59 No 538513				Oxidation time and temperature
						You may have hit on the key here, psychokitty! Reviewing the Boeseken relative article (Rec Trav Chim 55,786-790, 1936) on page 788 where the oxidation of interest experimental is described I can make out 35 degrees and terminee (terminate?) 24 hours. I would paste it up but can't do it from that PDF. It also appears they did hydrolyse with HCl at 80 deg. If somebee could please do a quicky translation of a couple paragraphs on Page 788. It is under the heading "Oxydation de la cetone II" see Post 487934 (Rhodium: "Peracid oxidation of unsaturated ketones", Novel Discourse) Somebee I know is running a few more batches and wants to try it and I'm sure he would report back the findings to me. The part on the HCl hydrolysis is on the first page and mentions the time, temp but no strength for a similar compound. Anyway keep them cards and letters coming psychokitty
		bio (Hive Bee) 11-02-04 05:21 No 539173				A better way with MEK (Rated as: excellent)
						Here I go again replying to my own post. CW you are going to love this, 80% of the work is now eliminated in the MePhBuO prep. The method below with slight modifications was tried at 1M test scale with great results. 77% molar yield or 124.4g from 106g PhCHO. The HCl was passed slowly keeping the temp < minus 5 deg (all absorbed)and stirred for 16 hours at ice bath temp. Immediate when stopped stirring into sep funnel. This shit loves to form emulsions with the oily phase trapping below the water in gobs when washing. After 3 hours no water separated (not surprised) so just proceded anyway. Now let me ask anyone who actually might be paying attention. How is this possible???.........."The mixture...shaken for sixteen to twenty hours. At the end of this time the water formed in the reaction had separated as aqueous hydrochloric acid and was removed." I guess I don't know how to shake. What probably really happened was 2 days later the water separated, from my experience. The one to one method was not what it was cracked up to be. Sat too long and way more tar and labor to separate the crap. from JACS 54, 336      .....................One-half mole of benzaldehyde was mixed with one mole of the alkyl acetone and one-fourth mole of hydrogen chloride gas passed into the cooled mixture. The mixture, which soon became red, was then shaken for sixteen to twenty hours. At the end of this time the water formed in the reaction had separated as aqueous hydrochloric acid and was removed. Without further treatment, the oil was distilled under diminished pressure (about 20 mm.). Somewhat more than half of the alkyl acetone was recovered and a small residue, probably consisting of dibenzal-alkyl acetone (styryl-( a-alkyl-)-styryl ketone), remained in the flask. The principal fraction, consisting of crude methyl (a-alkyl-)-styryl ketone, was obtained in a yield of about 90% based on the alkyl acetone consumed, or about 75% based on the benzaldehyde employed. The crude alkyl acetone fraction was treated with one-half mole of benzaldehyde and sufficient alkyl acetone to replace that consumed in the first reaction. Hydrogen chloride was then added and the reaction carried out as before. The process was repeated three times but could probably be carried on indefinitely. By using two moles of alkyl acetone to one of benzaldehyde and reworking the recovered alkyl acetone in this way, the amount of dibenzal derivative formed was greatly reduced, with consequent improvement in the yield of the desired product. from JACS 54, 336................... Anyway back to the grind.
		bio (Hive Bee) 11-02-04 07:36 No 539184				Calling all Peracid Guru's
						Chromics method for 15% peracetic from ca.35% H2O2 is about to be tried. Now Bio had an idea that if he used the perborate 4hydrate (same moles peroxide) instead of the Hydrogen Peroxide, which is mostly water, he should end up with an almost equal peracetic concentration with wayyyy less water, which if I understand correctly is detrimental to peracid oxidations. The perborate doesn't like to dissolve too well in the GAA so a lot must be used (10:1 ratio per the Perborate/Percarbonate review article. The little Oxygen bubbles just seem to bubble right on out. So.......what if the room temp moderated mixture was sealed and allowed to develop a few atmospheres of pressure? Thoughts anyone? Bio loves his new low pressure bomb, it makes things so easy and he gets more too! Sulfuric Acid catalyzed Peracetic acid with NaPerborate 1:10M SPB:GAA @ 40deg (20deg??) Required for 100g,624mm MePhBuO per twodogs procedure! 1)500-625ml Glacial acetic acid ........ ca 10M   CH3COOH  60.05 g/m x 10 = 600.5g x .995 = 597.5g/1.05d = 569ml 2)143g 929mm Na Perborate ............ca 1M 34.0g/m H2O2   NaBO2.H2O2.3H2O = 153.8 g/m 3)AcOH 597.5g + H2O2 34g/m = 631.5 x .01 = (6.31g x .98)/1.84d = 3.36ml H2SO4 Rhodium if you get a chance, please look this over. Will try it insitu the normal way and also premade peracetic (modified Chromic method as above)It is supposed to be sulfuric acid 1% weight of total contents that you referenced for me.(JACS,907,1946, Greenspan F.P.) Also the unreacted MePhBuO will be fractionated prior to the hydrolysis (HCl instead NaOH) although the concentration and time is still not clear per your excerpt from the 1936 Boeseken article. .........Phenylacetone by Bayer-Villiger Oxidation of 2-acetyl-1-phenylprop-1-ene Boeeseken & Jacobs Recl. Trav. Chim. Pays-Bas 55, 786 (1936) Peracetic acid treatment of 2-acetyl-propenylbenzene (3-methyl-4-phenyl-but-3-en-2-one) below 30°C resulted in the formation of phenylacetone enol acetate (2-acetoxy-1-phenylprop-1-ene), mp 131°C and bp 103°C/3mmHg. Heating the crude reaction mixture with aqueous HCl at 80°C gave phenylacetone.
		abacus (Hive Bee) 11-06-04 08:18 No 540001				heres my results
						Bio, Swim has been carrying out a few experiments of his own and seeing how you are still interested in this procedure, like me, i may as well share some results. 360g distilled benzaldehyde was mixed with 260g MEK in a 1L FBF and stirred in an ice bath (around equimolar amounts).  HCL gas was slowly added over two hours so that the weight of benzaldehyde/MEK mix increased by 75g.  The flask was stoppered, removed from the ice bath and the blood reddish solution was then allowed to sit for 2-3 days at room temperature. The HCL was then removed by dissolving the resulting methyl phenyl butanone in DCM and washing with NaOH solutions, brine, then clean water. The DCM was removed by distillation, residual water stripped off under vacuum, and then MPB vacuum distilled to give 360g. btw, no tar or polymerisation was ever observed. Not too bad. Baeyer Villager oxidation using sodium perborate then proved quite successful with similar results to your posts. Steam distillation was employed to seperate the resulting P2P.  The down side is the use of large amounts of GAA, so experiments involving recycling the GAA and unreacted MPB are currently on the drawing board.
		indole_amine (Hive Bee) 11-07-04 15:14 No 540201				?
						What was the final yield of purified propanone with the described procedure? indole_amine
		bio (Hive Bee) 11-07-04 20:22 No 540236				Results
						Glad to hear it's working, abacus. I had just about given up hope that anyone was going to try the method. You must be in favor with the  Aromatic Butenone Gods, not experiencing the "tar from hell" yet. Any theories why? Using RA ingredients I always had varying amounts especially after it sat more than 24 hours at ambient before workup. Your DCM extraction right up front is good. I have been using Hexane and also washing with base before water to minimize emulsions but the brine wash is at the end to remove water. Hexane or Petroleum Ether seem to be the best for crystallization. However, this is history now per my previous post. Surprisingly when fractionated after using the  JACS 54, 336 condensation method the MePhBuO came over a tighter range than ever before (about 8 degrees) and crystallized very nicely. Keeping at ice temp for the 16 hours was an idea from a previous run with better yield when the condensation mix was kept in the gassing ice bath (no stirring) for about 8 hours. Am convinced there is a non-exotic catalyst to get the yield way up. Sulfuric Acid in varying concentrations is used in many similar Peracid oxidations but my sense is that it would tend to form the epoxide or hydroxy epoxide. The recycle method may well do that although requiring a lot of work. Am still researching Mn catalysts and the sulfates come out on top. Please do post your continued findings or PM as I pretty much stopped posting as no one really seemed interested. Maybee there are other "closet" cases like you, LOL.
		n00dle (Hive Bee) 11-08-04 05:25 No 540355				Of any use? Oxone/dioxirane is easy to come by.
						On the Mechanism of the Bayer-Villiger Oxidation of Ketones by Bis(trimethylsilyl) Peroxomonosulfate. Intermediacy of Dioxiranes Camporeale, M.; Fiorani, T.; Troisi, L.; Adam, W.; Curci, R.; Edwards, J.O., J. Org. Chem., 55, 93-98 (1990) Dimethyldioxirane Epoxidation of α,β-Unsaturated Ketones, Acids and Esters Adam, W.; Hadjiarapoglou, L.; Nestler, B., Tetrahedron Lett., 31, 331-334 (1990) Epoxidation of Silyl Enol Ethers, Phthalides, and Enol Esters by Dimethyldioxirane Adam, W.; Hadjiarapoglou, L.; Wang, X., Tetrahedron Lett., 30, 6479-6500 (1989)
		abacus (Hive Bee) 11-08-04 10:01 No 540389				Bio I agree, washes were much easier when the...
						Bio I agree, washes were much easier when the organics were diluted in a suitable solvent. Toluene extractions were favoured for the Baeyer Villager. Indole Yield P2P from experiments on stated scale were around 138g when using vacuum distillation. Other experiments that involved steam distillation to isolate the post reaction P2P resulted in a bit less. Thats about it from me. Abacus
		lugh (Moderator) 11-10-04 01:26 No 540725				P2P in +90% yields (Rated as: excellent)
						In this article, p2p is synthesized by oxidation of trans beta methyl styrene in yields of over 90% On the Mechanism of the Bayer-Villiger Oxidation of Ketones by Bis(trimethylsilyl) Peroxomonosulfate. Intermediacy of Dioxiranes Camporeale, M.; Fiorani, T.; Troisi, L.; Adam, W.; Curci, R.; Edwards, J.O., J. Org. Chem., 55 93-8 (1990) Chemistry is our Covalent Bond
		bio (Hive Bee) 11-11-04 21:33 No 541083				epoxide/ester hydrolysis
						Thanks for finding that , lugh. Any chance of locating the 3rd one nOOdle posted? What I'm not entirely sure about is if the epoxide was made from the MePhBuO rather than the ester would it hydrolyse to the same product (2propanone)? Would try this if there is a known procedure similar enough to be adapted to the MPB.  Am thinking of using chromics HCl  rearrangement procedure for the hydrolysis of the ester. Is this really adaptable as is to unsaturated ketonic ester hydrolysis? Having a hard time finding one that uses acid instead of base. Vogel mentions sulfuric acid in acetic acid for ketonic ester hydrolysis but no experimental except for many base examples. Also in the 90% article,  J. Org. Chem., 55, 93-98 (1990),  the trans beta methyl styrene is also called propenyl benzene, correct?
		Rhodium (Chief Bee) 11-11-04 22:57 No 541103				trans-β-methylstyrene propenylbenzene
						trans-β-methylstyrene is also called propenylbenzene, correct? Correct. The Hive - Clandestine Chemists Without Borders
		psychokitty («») 11-12-04 01:36 No 541132				New info . . .
						First of all, the hydrolysis occurs in most publications that I've read using KOH, NOT NaOH.  Maybe that'll make the difference. As for recommendations as to how the syntheses protocol can be modified to advantage, it would seem that using potassium (or perhaps sodium) acetate in the peracetic acid reaction is the ticket.  Apparantly, it allows the reaction to complete in shorter time (1 HOUR!), with fewer side-reactions, and overall better yields.   Also, use of a saturated acetate salt mixture allows substituted (as in methylenedioxy-substituted) a,B-unsaturated ketones to be used as precursors to ring-substituted enol-esters, which are produced in good yield.  As for the dilution factor, in many of the articles that I've read (already mentioned), the percentage of acetic acid doesn't seem to impact the final yield of product, so my best guess is that Chromic's method should work well if not wonderfully.  The only catch is the use of a halohydrocarbon solvent as part of the biphasic peracid reaction mixture.  While this works wonders for making epoxides and diols out of alkenes, I wonder what it's effect will be when applied to the Baeyer-Villiger reaction.  DCM/performic acid has already been published as an effective reagent for the Baeyer-Villiger reaction using ketones as precursors.  But I have yet to find even one publication describing its use as  would be applied to a,B-unsaturated ketones. Aside from the acetate salt issue, lowering the temperature of the reaction to about 0°C seems to be the only other factor which might merit modification. Let me know if you have any additional questions, anyone.

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