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	Novel Discourse

	All 56 posts		Subject: P2P by grignard addition to acetylacetone trial		Please login to post		Down

		Bandil (The Archetypical "Good Guy") 05-17-04 00:22 No 507580				P2P by grignard addition to acetylacetone trial (Rated as: good read)
						P2P by grignard addition to acetylacetone Introduction: In Post 482060 (Rhodium: "P2P by grignard addition to acetylacetone", Novel Discourse), Rhodium suggest making P2P by adding acetylacetone to benzylmagnesiumchloride, and heating the product, such that it breaks down to P2P. This is an attempt to test the proposed method. Reaction details: 100 mL 2M BenzylMgCl in (obviously) dry THF  was placed in a 500 mL RBF and fitted with a claisen condensor. On this, a reflux condensor and a pressure equalized addition funnel was added. The funnel was filled with 10 mL acetylacetone (2,4-pentanedione), dissolved in 12 mL dry THF. The addition funnel was plugged with a glass plug. The cooling of the condensor was commensed, and the acetylacetone solution was introduced dropwise, while stirring the BzMgCl solution heavily. Within a minute heavy reflux was noted. Once all of the acetylacetone was added, the reaction was allowed to continue undisturbed for a few minutes. Once the reflux had died, the setup was lowered in a warm waterbath and heated at reflux temperature for four hours, while stirring heavily. The colour changed from brownish-yellow to at more clear yellow within ½ an hour. After four hours, the heating was discontinued. Once cooled down, everthing was dismanteled. The grignard addition product was placed in the freezer for 30 mins. 100 mL saturated NH4Cl (aq.) was also cooled in a freezer. 50 mL's of the ammonium chloride solution was added under violent stirring to the grignard addition product in one portion. No exothermic reaction was noted. The color did however change to a very opaque yellow. Stirring was continued for another 10 mins, untill no more change in appearance was noted.. The mixture was suction filtered. This took ALOT of time (45 mins), due to the fine precipitate. Alot of the THF had evaporated under the vacuum filtering, leaving only a small amount of organic material. This was collected using a separating funnel. The water phase was saturated with NaCl and extracted twice with THF. The combined THF phases where dried over MgSO4 and filtered. The THF was stripped (and recylcled after a date with some sieves ). The yellow remains, where submerged in a 200 oC oil bath, while being stirred heavily. Vacuum was applied, and pretty soon, a yellow/reddish distillate began coming over at 110-125 oC. Totally 5,5 g's where collected. This is a little more than half of what they get in the original procedure. The smell reminded alot of the known ketones. Conclusion: The oil will be subjected to GCMS in order to confirm the purity and nature. BP- and smell wise, it looks dead on like P2P. It was an amazingly small amount of work required to produce the material, so if it's tweaked a little so it'll work like a charm for everyone, im sure it will be a winner route to P2P's Some tweaks where used in this method, which probably caused the poor yield. THF was used, which will give a higher reflux temperature and the separation is ALOT harder than with ether. The next run, will be condicted as described in the original patent in ether. I'll be sure to keep you updated Regards Bandil Nuke the whales!
		Xicori (Hive Bee) 05-17-04 15:09 No 507707				High Bandil! Great to hear that you´ve tried...
						High Bandil! Great to hear that you´ve tried out this procedure!! It would be useful to filter the Mg-Salts through a pad of celite or clean sand to spead up the filtration! I´m also very much looking forward to hear about the GC/MS results. You might have some benzyl alcohol in there (it´s boiling point is quite near to p2p´s bp). Great work!
		Bandil (The Archetypical "Good Guy") 05-17-04 15:22 No 507708				Celite - great idea
						Of course... I had some idiotic idea that celite only was usable when it was unfilterable in the sense that everything came through. I'll give it some celite next time and run the stuff in ether. I'm pretty sure that a lot of the loss came from the difficult separation of the THF and sat. aquous NH4Cl But that will have to wait a few days - right now theres a very interesting experiment running. I'll post about it in some hours Regards Bandil Nuke the whales!
		Xicori (Hive Bee) 05-17-04 15:38 No 507710				The Et2O often gives lower yeilds in grignard...
						The Et2O often gives lower yeilds in grignard reactions, but the workup is way simpler (imo)! All the salts should go into the aqueous phase, so there is no more need for any filtration before phase seperation! >But that will have to wait a few days - right now theres a >very interesting experiment running. I'll post about it in >some hours - nice to hear that! good luck!
		randolph_carter (Hive Bee) 05-18-04 00:12 No 507796				killer test bandil....
						this is excellent news!!!! great writeupp as well..... i had read the post by "rhod the mod" as well and found it extremely interesting!!!!  i had not had enough freetime to get/read the patent for myself but now it appears that i will need to make the time....... we look forward to further info on gc/ms analysis so that we will have a better handle on the actual versus expected impurities/side products that will have to be dealt with.... now a lizard has another thing to do with his 2.4 pent* besides lysergide dream research...... thanxxx again bandil!!!! jus a ravin in da pm..... "remember little ones, love is real,not fade away, so pass some ammo on today......"
		Bandil (The Archetypical "Good Guy") 05-18-04 15:52 No 507910				Results are in!
						The GC-MS analysis gave the following results: 59.54% P2P 22.62% 5-phenyl-4-methyl-3-pentene-2-one 17.84% unknown1, MW=182 g/mole It appears that the vacuum was to high for the 5-phenyl-4-methyl-3-pentene-2-one to fully convert to P2P. I'll try to tweak the reaction, by heating the undistilled product to 150oC for an hour or so. This should drive of the nasty acetone, and leave the nice P2P, to be distilled! Another nice tweak would be to use sodium acetylacetonate instead of acetylacetone directly. This would allow a 1:1+ molar ratio of the grignard reactant to the acetylacetone. Any reason why this shouldn't work? With a little work im sure this method could be among the higest ranking P2P production methods available to ordinary folks I'll try it out right away Enjoy folks! Regards Bandil Notes: [1]: Prometheuz will analyze this further soon to figure out what the mystery molecule is Nuke the whales!
		Rhodium (Chief Bee) 05-18-04 17:42 No 507946				Good work!
						If you use sodium acetylacetonate salt to start with, you will not be able to form the six-membered ring with a very delocalized charge (Compound II in the article in Post 482060 (Rhodium: "P2P by grignard addition to acetylacetone", Novel Discourse)), as Na+ is only monovalent (as opposed to the divalent Mg2+ ion). I must however confess that I'm fully unable to determine if that difference is favorable, detrimental or inconsequential for the desired reaction. Anyone? The Hive - Clandestine Chemists Without Borders
		GC_MS (Hive Addict) 05-18-04 18:13 No 507957				m/z
						17.84% unknown1, MW=182 g/mole Considered substituted naphthalenes? $
		Bandil (The Archetypical "Good Guy") 05-18-04 18:52 No 507966				Only one way to find out!
						Rhodium> Then how about simply making the acetylacetonate salt from magnesiumhydroxide? That would give the Mg2+ ion. Anyway I trust empircal- over theoretical knowledgde at any time... So I guess we'll have the answer in a few days Sit tight! Regards Bandil Nuke the whales!
		Nicodem (Hive Bee) 05-18-04 19:50 No 507988				Interesting work
						m/z=182 is probably just a self condensation product of acetylacetone. There are a few different possible products of condensation of two acetylacetone molecules having the MW=2*MW(acetylacetone)-MW(H2O)=(2*100-18)g/mol=182g/mol. What bothers me is the presence of 5-phenyl-4-methyl-3-pentene-2-one. I always thought that eliminations of beta-hydroxy-ketones don't occur in basic conditions. NH4Cl is surely not acidic enough to cause the dehydration. Maybe part of the product inevitably dehydrates due to the distilling temperature while part of it goes trough the so much preferred retroaldol reaction. I’m still don’t completely understand where this retroaldol step happens, is it during the Grignard, at the point of neutralization or during the distillation? I guess I should read the paper once more. Bandil, is it possible that some of the NH4Cl passed trough the filtration or is maybe a little soluble in THF? I would suggest washing the organic phase dissolved in DCM with some NaHCO3 before the distillation (using diethyl ether instead THF would make things easier here). This should prevent acid catalyzed dehydration at the boiling temperature and hopefully facilitate the retroaldol. About the sodium acetylacetonate, I think once in the THF solution it will be able to exchange the cation as soon as the reaction starts. Anyway, I don’t think that a six-membered Mg-acetylacetonate complex is necessary for the BnMgCl addition at the carbonyl. It might bee of some importance for the subsequent retroaldol but at that stage there will already bee enough Mg2+ around while the NaCl should precipitate. Like Barium said, somebee has to try it and we will know. Bandil, good luck for the second episode… “The real drug-problem is that we need more and better drugs.” – J. Ott
		Novice (Newbee) 05-18-04 20:28 No 508001				Use magnesium metal
						Bandil, I suggest you make it simply from adding magnesium metal to the acetylacetone, it should give the desired Mg2+ salt, and the evolution of hydrogen. It works for ethanol (pKa=15,9) and it definately should work for acetylacetone (pKa=9). Ac2CH2 + Mg -> Mg(Ac2CH)2 + H2 You might have to heat it for some time though, but you won't get any water as a byproduct.
		Prometheuz (Hive Bee) 05-18-04 22:57 No 508059				Identity of the "mystery peak" revealed!
						According to database-search on the mass-spectrum of the unidentified peak, at MW 182, the compound is.... Bibenzyl - 1,2-diphenylethane, C14H14. Must have been high for needing a database to figure that one out... I've tried to attach some of the GC/MS-report in PDF. Could have added in some database-hits, but found that it would be a waste of space. In conclusion, I'm quite sure about the identification of the peaks; Peak 1: P2P Peak 2: 5-phenyl-4-methyl-3-pentene-2-one Peak 3: 1,2-diphenylethane Sorry for not contributing with any attempt of chemical explanations to the analysis-results right now, but it has been a looong day... To fathom Hell or soar angelic Just take a pinch of psychedelic
		Prometheuz (Hive Bee) 05-18-04 23:33 No 508065				Yield correction!
						Fuck! Never trust any "smart" program to do the data-calculations for you, and just shutting your brain off! Anyone can see that there are more than just the 3 peaks. I mingled a bit with the data manually, and ended up with a different result. I'll post the results shortly! Unfortunately it seems like the actual yield is down to ~33%, and that there was formed quite a bit of benzylalcohol, and some other, harder to identify substances in lower amounts. To fathom Hell or soar angelic Just take a pinch of psychedelic
		Prometheuz (Hive Bee) 05-19-04 01:02 No 508081				New results in!
						OK folks, this should be closer to the real thing; for some reason the first results only integrated 3 of the peaks, and there are more than 10 present. The attached file shows the results with 10 peaks integrated. According to this, nearly 25% of the mixture was benzylalcohol. The yield for P2P is down to ~31 %. I'm too tired to analyse all the peaks right now, but I think the following is correct, according to the more detailed analysis: Peak #1: Benzylalcohol Peak #2: P2P Peak #3: Probably 1,1-dimethyl-2-phenyl-ethanol Peak #7: 5-phenyl-4-methyl-3-pentene-2-one Peak #10: Bibenzyl I promise I'll try to use just a BIT brain-capacity before posting again. To fathom Hell or soar angelic Just take a pinch of psychedelic
		Bandil (The Archetypical "Good Guy") 05-19-04 12:00 No 508196				HCl instead of NH4Cl
						It seems that the authors only treat the big addition molecule with ease so it does not break down to P2P. Why not simply wash everything with dilute hydrochloric acid? This could be followed by heating everything to 150oC to make sure everything "deacetonylates" (probably spelled like crap, but im sure you know what i mean). Wouldn't that facilitate the desired reaction? Regards Bandil Nuke the whales!
		Bandil (The Archetypical "Good Guy") 05-22-04 13:48 No 508778				Improvement and proof of concept (Rated as: excellent)
						Improvement and proof of concept Introduction: The last trial was run with a premade, very dilute benzylmagnesiumchloride in THF. This made separation and workup tedious and the end results where very impure. Since then some improvements has been made, which is presented here. The benzylmagesiumchloride is prepared from benzylchloride, which tends to pose difficulty for some bees. Reaction details: Initial preparation of the ammoniumchloride solution: Two 250 mL Erlenmeyer flasks was filled with the following: 123.3 g 30% HCl was placed in an Erlenmeyer flask w. magnet and stirring was commenced. To this a 61 g aqeous 24.5% NH3 solution was carefully while stirring. Very exothermic, so go easy here... After addition, the total volume of each flask was 150 mL. This was toppen of with water to a total volume of 200 mL and placed in the freezer for one hour, at which time the internal temperature had reached -15°. A small amount of white precipitate was on the bottom of each flask, indicating that it was a saturated solution (thus no need for isolating ammoniumchloride if it is not at hand). Formation of BzMgCl: All the glassware used herein was dried in the oven at 150°C for one hour prior to the setup. 19.2 g Mg turnings (99.9% purity) was placed in a 2 L RBF with large magnet. This was covered in "dirt cheap food grade ether" , which had been predried over 4 g's 3A molecular sieves for 20 mins. A claisenadaptor and a vigreaux condensor was fitted. The top of the condensor was plugged with a little toilet paper. To the other arm of the claisen adaptor a pressure equalized funnel was attached. 96 mL(0.8 mole) PhCH2Cl in 200 mL ether was dried over 10 g's 3A mol. sieves for 30 mins. After drying, it was poured into the addition funnel, and the sieves rinsed with a little extra ether. The funnel was then closed with a glass plug. 1/4 of the ether/benzylchloride was added to the 2L RBF, while stirring heavily. After addition and subsequent stirring for 30 secs, the RBF was warmed with my bare hands, which immediately set of the reaction. The ether went white and started refluxing heavily. After cooling down a little, the remaining benzylchloride was added dropwise, such that a steady reflux was maintained. Took about 30 mins total. After addition, it was allowed to stirr for another 30 minutes, to ensure total conversion of the benzylchloride. Reaction with acetylacetone: 0.4 mole(40 mL) acetylacetone was dissolved in 50 mL ether and dried over 5 g's sieves for 30 mins. This was placed in the funnel and the sieves rinsed with some ether. The dropwise addition of the acetylacetone caused an immediate precipitation of some white salts (which was not the case with THF), and reflux within 30 seconds1. Once everything had been dripped in over a timespan of 15 mins, the reaction was allowed to continue untill it had cooled to room temperature. The claisen adaptor etc. was dismantled, and the condensor was attached directly to the RBF. The RBF was placed in an oil bath and refluxed overnight. Hydrolysis: The RBF was cooled in an ice/water bath and 200 mL ice cold ammoniumchloride was added in one portion, causing a very exothermic reaction. This was stirred for 20 mins, while cooling. The whole mess was filtered through celite, which was horribly difficult. It took about one hour for everything to go through, and most of the ether was lost due to vacuum in the receiving flask. The precipitate was washed with another 200 mL cold ammoniumchloride solution. Filtration was very close to impossible here. So the sludge was placed in a sep. funnel and extracted with 2*50 mL DCM. This was very easily separated. The ether / water phase was also separated and the water extracted twice with fresh ether. Both of the organic phases was washed with brine and dried over epsom salt. Afterwards, they where combined and the solvent stripped off, leaving a oily yellow residue. Isolation of the P2P: The yellow residue was placed in a 500 mL RBF and heated on an oilbath at 150°C for 1 hour, to make sure all of the right molecules cracked up. At about 100°C a reaction took place and alot of acetone evaporated of. Things where rigged for vacuum distillation, and heated. At 100°C 20 mL liquid came over, which had a density of 0.8, indicating that it was the toluene formed as a byproduct in that fraction. The smell confirmed this, so the fraction was simply discarded. At 120°C-128°C 20,5 g P2P came over (purity still to be confirmed by GC-MS). The density was 1.0 g/mL, which is dead on the same as merck states, and it was completely colourless as opposed to the previous THF run. The smell was also very "keton'ish" The oil was aminated very successfully, using the usual wet borohydride reduction, giving a large, but unspecified, amount of pretty shiny crystals (no amount needed, as this was a proof of concept run) Conclusion: Much nicer run that the previous THF trial. Seems ether is the way to go here. There are still alot of things to improve, before it is a feasible reaction. But I really think that this could end up being the method for making P2P's in adequate amounts. The solvent amounts are minimal, and the reaction doesn't require anything really suspicious. Forthcoming tweaks: The original patent treats the addition molecule with ease to avoid the break down to P2P. Most likely no reason to do that here. Next time dilute HCl will be used directly. Perhaps more of the sludge can be dissolved aswell! The filtration is the largest problem in the reaction. I think it should be possible to mix the acid in and stirr for a while. Then directly extract with ether a few times. It seemed to separate just fine with DCM, so i cant see why ether shouldnt do so aswell. Finally, after reading the original patent I am rather convinced that using sodiumacetylacetonate will work very well AND even improve yields. The patent states that acetylacetone exists in two tautomers in a 78:22 ratio. The smaller portion gives rise to the bis-addition product, which is unuseable. By making the sodium or magnesium salt first, and THEN adding it to the grignard reactant. This should eliminate the bis-addition as far as I see it. Also half the amount of the benzylchloride should be called for. I am very interested in some of you hardcore chem heads thoughts on that idea? Notes: [1] Benzylchloride is a heavy lachrymator (teargas), which I found out the hard way Seemes a little benzylchloride escaped while changing the setup... More caution please! Nuke the whales!
		Megatherium (Hive Bee) 05-25-04 18:36 No 509549				Another bee agrees
						I am very interested in some of you hardcore chem heads thoughts on that idea? If you use sodium acetylacetonate salt to start with, you will not be able to form the six-membered ring with a very delocalized charge, as Na+ is only monovalent (as opposed to the divalent Mg2+ ion). Me thinks this would be no problem, as the same magnesium coordinated di-anion would be formed eventually: CH3-C(=O)-CH2-C(=O)-CH3  --> CH3-C(=O)-CH=C(-O-Na+)-CH3 + Bzl-Mg2+Cl-  --> CH3-C(-Bzl)(-O-Mg2+Cl- )-CH=C(-O-Na+)-CH3   --> Mg2+ bicoordinated enolate: CH3-C(-Bzl)(-O-)-CH=C(-O-)-CH3 + NaCl The main problem in this synthesis is that beta-hydroxy aldehydes are easily dehydrated (explaining the 22,62 % 5-phenyl-4-methyl-3-pentene-2-one). In Post 482060 (Rhodium: "P2P by grignard addition to acetylacetone", Novel Discourse) they say:  By heating product IV without I2 (or in a few irreproducible runs even with I2), 40 ml of a different distillate, b.p. 100-130°C/10mmHg was obtained. Its main component IX could be obtained by refractionation at 80°C/6mmHg or 71°C/3mmHg Now the without I2 (or in a few irreproducible runs even with I2) is pretty peculiar, since it is reported(*) that I2 acts as a Lewis acid in the dehydration (upon distillation) in compounds as 4-hydroxy-4-methyl-2-pentanone.  Likewise, such compounds are dehydrated upon warming with dillute HCl.  What bothers me is the presence of 5-phenyl-4-methyl-3-pentene-2-one. I always thought that eliminations of beta-hydroxy-ketones don't occur in basic conditions. NH4Cl is surely not acidic enough to cause the dehydration. Maybe part of the product inevitably dehydrates due to the distilling temperature while part of it goes trough the so much preferred retroaldol reaction. I’m still don’t completely understand where this retroaldol step happens, is it during the Grignard, at the point of neutralization or during the distillation? I guess I should read the paper once more. I think that since since the grignard is quenched with aq. NH3.HCl (aq), the bi-coordinated Mg complex is destoyed forming the easy dehydratable CH3-C(-Bzl)(-OH])-CH2-C(=O)-CH3.  When dehydration occurs, the reaction is stuck.   In my eyes: the retro-aldol occurs as follows: 1)CH3-C(-Bzl)(-OH])-CH2-C(=O)-CH3  an electron pair of the red oxygen makes an hydrogen bridge with the blue hydrogen 2) CH3-C(-Bzl)(-OH])-CH2-C(=O)-CH3  an electron pair of the green oxygen delocates, starting the retro-aldol reaction.  This is an intramolecular concerted reaction since while the red bond breaks, a bond is formed between the blue proton &  the red oxygen. So, from a theoretical point of view adding HCl would not only disturb the concerted retro-aldol, but it would favor also the deshydration (which is a bad thing).  I guess the retro aldol is just a destructive distillation, following a neat reaction mechanism.  (*): Organic Chemistry, Morrison & Boyd, 6 th ed, p 807 Aztec fanclub member & reaction mechanism freak
		Bandil (The Archetypical "Good Guy") 06-11-04 09:42 No 512767				Huge improvement! (Rated as: excellent)
						Boosting the P2P yield past 60% Introduction: The previous trials used a double excess of benzylchloride, and caused the formation of the bis addition product (22% according to the original article). This resulted in a yield of P2P well below 20%. By using premade sodiumacetylacetonate, it was easy to push the yields past 60% with little effort. Theory: The higher yields can be explained by two factors. Firstly, only one mole equalivent of benzylmagnesiumchloride is required per mole of acetylacetonate, as it has been deprotonated prior to the addition. Secondly acetylacetone exists as two different tautomers (denoted a and b in the original article) in a 78% and 22% mixture. Only the 78% will give rise to the correct mono addition product. The remaining 22% will give rise to 2,4-dibenzylpentane-2,4-diol, which is unuseable in this context. By using the deprotonated version, only the a tautomer will exist, and thus only the mono addition product is formed. Also, by using aqueous dilute hydrochloric acid, instead of sat. aq. NH4Cl, the separation of ether and water can be done without filtration. Reaction details: Formation of sodiumacetylacetonate: 1 mole dry NaOH was suspended in den. ethanol. This was stirred heavily in a cool waterbath, while stirring heavily. 1 mole acetylacetone was added dropwise. A thick white precipitate was quickly formed, and when all of the acetylacetone was added the whole mess looked like white porrage. The ethanol and formed water was removed under vacuum, leaving a crystalline white powder (quantitative yields of the sodium salt). This was used as is in the following reaction. Reaction with the grignard reactant: In a 2 L RBF 0.4 mole mole BzMgCl was prepared in the usuall manner (using in situ drying with mol. sieves because of an inital failure) in 150 mL ether. 48.8 g (0.4 mole) sodium acetylacetonate was added dry portionwise. This caused a VERY vigourous reaction and heavy reflux, so please use a 2L flask for this reaction. Some of the crystalline material clinging to the flask neck was rinsed down with more dry ether. The sodium acetylacetonate was added over ½ hrs along with the extra ether. Once added, the mixture was refluxed, using a water bath as heat source, for 6 hrs. Some ether was lost during this time, causing the reaction to run very dry in the end. A better reflux condensor should take care of this problem. More ether was added after this period to make everything more stirrable. 100 mL (approximately 1 mole) concentrated aq. HCl was diluted with 250 mL H2O and added dropwise while stirring. A very exothermic reaction was set of, causing everything to reflux vigourosly while the first half of the acid was added. Once it had cooled down another 100 mL's H2O was added to dissolve the remaining sludge. The ether was separated, and the water phase extracted twice with 100 mL's ether. The combined ether portions where washed once with water, followed by a wash with brine. Finally it was dried over MgSO4, giving a yellow clear ether phase. The ether was stripped and the remains was placed in a 90 °C waterbath with aspirator vacuum applied. This caused a few mL's toluene and benzylalcohol to boil of. Afterwards the remains where distilled using an oil bath and aspirator vacuum. A small forerun consisting of 2 mL's clear liquid came over at 90-100 °C, which was discarded. At 105-112 °C 33.35 g slightly yellow oil came over. This corresponds well with the usual P2P BP. with aspirator vacuum. The smell and density were very consistent with past data. A small portion of the oil was aminated reductively successfully (not worked up yet - but the reduction seemed to indicate a very pure ketone), and another portion was shipped of to GC-MS testing (results should be in by monday). Conclusion: With a little more research this could very well turn out to be the ultimate route to P2P's The yield (60%+) was extremely high using this method (although it was performed quite sloppy). Tried poodles method with direct addition of acetonitrile, which gave less than a 5% yield. So if anyone is going to play around with benzylchloride grignards - please use this method instead! The reactants are relativily easy to procure, so the road is wide open for the perfume industry seeking to make new fragrant ketones Have a super weekend everyone! Regards Bandil Nuke the whales!
		Xicori (Hive Bee) 06-11-04 15:26 No 512797				Yes, Bandil, you did it!!
						Yes, Bandil, you did it!! 60% from Benzyl chloride, heh, thats not too bad! ...great idea to use the sodiumacetylacetonate instead! I´m awaiting the GC/MS results with great interest! - but its very likely that theres still a good amount of benzyl alcohol present, because of close-together boiling points. - If that turns out to be true a bisulfite purification step would be in order - without doubt some work, but easy and quick to perform! I wish you good luck! xicori
		Bandil (The Archetypical "Good Guy") 06-11-04 16:07 No 512804				Well benzylalcohol should only be formed if...
						Well benzylalcohol should only be formed if water was present - and the conditions are quite anhydrous Also - the post ether extraction mixture was kept at aspirator vacuum @ 90°C for one hour. This should remove most of the benzylalcohol... But yes - im also eager to see the GC result Nuke the whales!
		Bandil (The Archetypical "Good Guy") 06-11-04 17:38 No 512822				GC-MS results are in
						The P2P was GC-MS, and was over 86% pure , with the remains being benzylalcohol. The latter is inert in the reductive amination, and the P2P is thus dandy for use straight away. The benzylalcohol is probably formed from water entering the system (most likely traces in the sodiumacetylacetonate). A good way to improve things could by by making the acetonate in a healty excess of IPA. When the IPA is stripped, the water will be carried of as an azeotrope, leaving the acetonate bone dry. Perhaps lower reactions times will even improve yields, as the reaction wont be exposed to atmospheric moisture. Happy weekend and joy Regards Bandil Nuke the whales!
		Xicori (Hive Bee) 06-11-04 18:45 No 512835				nice! 86% isnt to bad!
						nice! 86% isnt to bad! The benzyl alcohol may be formed when you hydrolize excess grignard reagent with the acid or NH4Cl-Solution... There is no 100% convertion rate of your substrate with the BzMgCl. best wishes x
		Prometheuz (Hive Bee) 06-12-04 15:53 No 512990				GC/MS analysis
						Ok, HERE's a short analysisreport of the GC/MS. Not the most user-friendly program I've used, but hope it's illustrative. The names of the different peaks has been found from database-searches and plain logics. Still 4 small annoying peaks with MW=174. With all peaks taken in consideration, the yield was 78,44%. A nice result... To fathom Hell or soar angelic Just take a pinch of psychedelic
		GC_MS (Hive Addict) 06-12-04 17:42 No 513005				MW
						Still 4 small annoying peaks with MW=174 Sure it is not 176? Aztecunnilingus Maximus
		Bandil (The Archetypical "Good Guy") 06-14-04 15:49 No 513329				174 peak
						The peaks at 174 are the dehydration product XIa and XIb from the article: 5-phenyl-4-methyl-3-pentene-2-one. Perhaps a slower acidification at lower temperature will eliminate these. But they only constitute a few percent of the distillate.  Concidering the ease of the workup using hydrochloric acid directly, there has to be a serious advantage to using a weaker acid before i'm willing to do so. Regards Bandil Nuke the whales!
		Bandil (The Archetypical "Good Guy") 06-21-04 10:00 No 514577				Strange lack of attention?
						It ponders my mind why this method has gained so little attention? Personally I don't care, but it seems strange that people actually scrapes the phosphorous of a gazillion matchbooks to make a little meth. Also getting iodine from tincture and ephedrine is the same hassle. For this reaction all of the reactants are very easily obtained without suspicion (as opposed to the aceticanhydride method). The reaction itself is very easy, assuming that sieves are available. Today sieves are as normal a purchase as flour, so that obviously can't be the issue. The yield is about as high as they get - and this is even without proper optimization. I'm sure it could go well past 70% with a little work.  Is it because the word "Grignard" scares many "want to make p2p's" people? Grignard reaction requires that people are carefull, but they are by no means hard to start. Just follow the given steps and it will initiate. Perhaps it should have been posted in the stimulant forum aswell; or does it belong here in the novel discourse forum? Oh well - i'm just curious anyway Regards Bandil Nuke the whales!
		GC_MS (Hive Addict) 06-21-04 11:10 No 514586				Stimulants
						Perhaps it should have been posted in the stimulant forum aswell; or does it belong here in the novel discourse forum? They already have problems with GAKK, pfed, HI/RP and HCI acid. They can fill a whole forum with the problems related to that one single easy-as-fuck reaction. Are you serious you want to introduce them to Grignard? You may be held responsible for a whole series of lethal accidents. The few ppl who frequent the Stimulants forum but still have a basic understanding of chemistry will visit the Chemistry, Novel Discourse etc fora as well. Otherwise, I wouldn't be surprised to read somebody has sniffed 100 mg of Grignard complex instead of "ice" somewhere in the near future. But it's your research . Aztecunnilingus Maximus
		moo (Hive Bee) 06-21-04 11:23 No 514589				I guess H2S fumes and ketene is the stimulants
						I guess H2S fumes and ketene is the stimulants forum choice right after fighting with gak. Good work! fear fear hate hate
		Bandil (The Archetypical "Good Guy") 06-21-04 11:27 No 514590				GC_MS> Yeah - I see your point.
						GC_MS> Yeah - I see your point. But this reaction is of course not limited to pure P2P... That was merely a proof-of-concept run I'm sure a bromo/chloromethylation of dimethoxybenzene, dimethylether-toluhydroquinone, benzodioxole etc., could provide mighty interesting compounds to work with But the whole point of my last post was simply to express my "regrets", that such a treasure reaction goes almost unnoticed into the ancient posts... The same was almost about to happen to the cyanate route to the aminorex's, before it was tried out. Personally I could simply "not-give-a-f...", because there is a simple way for my alter ego to make many of these wonderfull compounds now. But the whole reason for posting it here was for others to gain something from it. Alas it seems that there is lacking a little adventurous spirit from time to time . Anyhow - i'm not complaining; merely wondering Have a nice day, regards Bandil Nuke the whales!
		Nicodem (Hive Bee) 06-21-04 12:27 No 514598				It's just perfect as it is
						Bandil, you can bee sure your work was and still is much appreciated. Consider the lack of response as a sign that you left us speechless. Believe me, some look at your work with great admiration. “The real drug-problem is that we need more and better drugs.” – J. Ott
		GC_MS (Hive Addict) 06-21-04 12:33 No 514599				Reply
						Nobody or only few ppl replying to your experiments does not necessarily mean nobody is interested in what you have been doing. Mind that not all 5200+ registered nicks stand for a chemist qualified by education or self experience, and also keep in mind that not all people who might understand what you have accomplished are also interested in the procedure. Although it is a nice method, I have no interest in synthesizing P2P, nor in the synthesis of other phenyl-2-propanones. This makes me putting energy in other synthetic endeavours, neglecting what you have been doing but suffering a similar fate . Aztecunnilingus Maximus
		Xicori (Hive Bee) 06-21-04 13:16 No 514601				hey! Bandil, there is for sure great interest...
						hey! Bandil, there is for sure great interest on your research, keep on posting! And I´m sure there will be a lot bees have to add when they try the procedure for themselves... ...SWIM is very limited on time right now, but your method is on top of my list of what to try out next ;) A different substrate like 2,5-Dimethoxy benzyl chloride/bromide might be also very interesting (i´ll try this out for sure, just wait til august)! keep the wonderful work up, many people are very thankful for it (even if they don´t post here!) ...and the Novel discourse is a way better home for your threads than the stimulants have a nice summer!
		armageddon (Hive Bee) 07-08-04 06:42 No 518124				Wow! Nice done!
						My compliments to you Bandil - very impressive! A real breakthrough would I say. Thanks for your work, keep on. Greetz A "..ein Trank von unterschiedlicher Farbe, in ihm ist Heilung für die Menschen."
		armageddon (Hive Bee) 08-02-04 18:41 No 523253				much cleaner acetylacetonate salt..
						To get very clean sodium acetylacetonate suitable for above Grignard rxn, you should try the following: suspend 20g NaOH(s) in 250ml ice-cold abs. EtOH in RBF, stir to dissolve as much as possible, place in cold water bath and let cool. When done, attach reflux condenser and slowly add ~1.05 eq. acetylacetone (~53ml) via addition funnel while stirring very vigorously. When all acetylacetone is added, the reflux condenser is replaced with a three-way adapter fitted with downward condenser and the (viscous) suspension of crystals/ethanol/water is reduced to at least 2/3 of its volume using slight vacuum, then everything is cooled very slowly, first in cooling bath, then in fridge. The precipitated acetylacetone*Na is vacuum filtered and rinsed with cold, anhydr. acetone and the remaining mother liquor is again concentrated to obtain a second crop of crystals after again adding some dry acetone to it. The resulting crystals are put into a dry RBF which is evacuated to dry them, as usual. The yield is only 85% of theory (around 60g from 0.5mol acetylacetone), but purity is outstanding (shiny little plates) - and concerning the few grams of acetonate salt remaining in the residual mother liquor: well there are always losses, right? The price to pay for purity... (although I don't know if high purity is really essential in this case... ) If you experience problems with Grignards not wanting to start when using acetylacetonate prepared like described above, simply dry your acetylacetone*Na in a desiccator over molar sieves for some days next time - should become "bone-dry", too. And if it still doesn't work, you know at least the reason was not the Na salt being too wet... Greetz A Pleased to meet you hope you get my name. But whats puzzlin you is the nature of my game!
		armageddon (Hive Bee) 08-09-04 22:09 No 524485				anhydrous.. (?)
						Hi! A friend of mine (I'll call him SWIA for simplicity ) just did his first Grignard reaction with benzyl chloride and acetylacetone (sodium salt), and succeeded... OK so far nothing important, but the surprising detail: He didn't dry any glassware prior to using it, nor did he use drying tubes, and the weather was only so-so (high humidity and temp.) - he simply dried the BzCl/ether solution with molecular sieves, as well as the ether he used as solvent, and SWIA used in-situ drying (he just added several grams mol. sieves to the Mg/Et2O prior to adding the BzCl-soln., like described by Bandil). And his molecular sieves were 4 Angstrom pore size (4A) and were not dried/activated by microwave or other methods, just used directly out of the (air-tight) container.. And all glassware SWIA used was as moist as the air was that day - and the grignard complex formed after stirring the Mg/Et2O together with 1/4 of the BzCl/Et2O soln. and warming the flask with bare hands, just like described... ...but SWIA told me he would strongly advise using a big reflux condenser or even better double-surface condenser instead of a vigreaux - he lost 250ml ether during the rxn, and had to leave the lab for a while due to becoming a bit drowsy... (so better use that reflux condenser with cold water) But the point is: even a bee with sloppy technique (like SWIA) and absolutely NO experience with grignards is able to reproduce the results of above method, if the necessary precautions are taken (ether is explosive, volatile, etc.etc.blabla). Don't be afraid, try it! With proper in-situ drying, this grignard rxn is really hard to screw up IMO! (Oh, and don't make the same mistake like SWIA and store your recovered ether in the same PE flask whose bottom is still covered with the mol. sieves from the initial solvent drying: his ether got dark-brown overnight upon standing in the fridge and scared the shit out of SWIA because of all the stories bout self-ignition of dried, peroxide-containing Et2O during shaking - until he figured to add some water/FeSO4 and let again stand overnight instead of shaking it - which luckily restored both the colorless appearance of the Et2O and SWIAs feeling of relative safety.. ) Greetz A Pleased to meet you hope you get my name. But whats puzzlin you is the nature of my game!
		armageddon (Hive Bee) 08-10-04 21:27 No 524682				strange distillate...
						Hi bees! My buddy SWIA vac distilled his ketone gotten from said AcAc Grignard twice - and collected some strange fractions..(?) First, some different clear liquids came over, followed by a nice fraction of yellow oil - so far so good. He then decided to redistill, because the smell of the oil was still somewhat disgusting and not really like phenylacetone at all... Said done. First some small amount of clear liquid came over below 80°C at 270torr. Then, a small fraction was collected at 150°C (corresponding to ~185°C at 760torr) - probably benzylchloride, SWIA thought - at least it would explain the disgusting smell of the raw product.. Then, nice greenish ketone came over at above ~165°C (just like P2P should), but the amount was only roughly half of the original volume! Then distillation ceased and SWIA had to crank the heat control up to over 350°C to be able to collect a large fraction between 210° and 230°C - WTF is that??? Appearance of the unknown substance is oily, slightly yellow and the bp should be around 260°C at ambient pressure - maybe 4-benzyl-3-pentene-2-one? Its bp would match, and https://www.rhodium.ws/pdf/p2p.acac-grignard.pdf  states that said ketone is obtained by heating the bis addition product of this reaction at 130°C under vacuum followed by distillation, so maybe...? This really puzzles me, especially because you guys have spent that much effort in analyzing the product!? (did SWIA use too little HCl for hydrolysis maybe?) Any ideas about what could've happened? [EDIT] after some more 24hours in the fridge, the P2P SWIA isolated has still its beautiful colour - while the higher-boiling fraction has become strongly yellow-tinted[/EDIT] THX A Pleased to meet you hope you get my name. But whats puzzlin you is the nature of my game!
		armageddon (Hive Bee) 08-18-04 10:16 No 526064				another reply to myself...
						The strange high-boiling ketone SWIA isolated during redistilling his phenylacetone didn't only take on a deep yellow/orange color, but also solidified after being kept in the fridge (+7°C) for one week... Appearance is yellow/white, the crystalline mass consists mainly of many clear needles... WTF is that? Input is greatly appreciated! Greetz A Pleased to meet you hope you get my name. But whats puzzlin you is the nature of my game!
		Bandil (The Archetypical "Good Guy") 08-18-04 11:25 No 526071				The dehydration product!
						Perhaps the dehydration product? It's higher boiling and will most likely solidify upon storage at low temperatures... Cocaine blows!
		armageddon (Hive Bee) 08-19-04 13:40 No 526294				lazy..
						Beat me for not wading through the original reference, but: How does the dehydration product form? Or better said: what did SWIA do wrong? He told me that the "good" ketone he isolated was successfully aminated via leuckart with good yield.. so some minor error must have happened, I'd suppose? I didn't notice you got any of this wierd by-product - did I miss something? Greetz A Pleased to meet you hope you get my name. But whats puzzlin you is the nature of my game!
		Nicodem (Hive Bee) 08-19-04 22:50 No 526351				Maybe acid remains?
						Just avoid using any acid stronger than Bandil used to quench his Grignard product (he used ammonium chloride, I think) and most importantly wash the ether with a bicarbonate solution before doing the disstilation. As long as there is absolutely no traces of acid present while distilling, the elimination side reaction should bee kept at minimum (in my opinion at least). Anyway, you did not gave details on your work up of the Grignard. It might have been something else? “The real drug-problem is that we need more and better drugs.” – J. Ott
		Bandil (The Archetypical "Good Guy") 08-20-04 07:14 No 526430				I used dilute HCl in the last run, which gave...
						I used dilute HCl in the last run, which gave about 20% dehydration product. I also forgot to wash with bicarbonate... Great idea I'll be sure to try that out in the forthcomin up-scale run Regards Bandil Cocaine blows!
		armageddon (Hive Bee) 08-20-04 12:33 No 526460				well then
						Hm, I used excess HCl 'cuz I wasn't sure about its concentration - too bad... Bandil: be sure to use good cooling and a condenser with wide inlet, and clamp everything very tight - I don't know if you read my post in "lab mistakes", but the pressure buildup can become a serious problem with scaleups... (thanks for your responses btw!) [edit] Oh, the workup - of course: after hydrolysis, the ethereal layer was separated and the rxn extracted 2x with more ether, then the combined extracts were washed with brine, dried over Na2SO4 and solvent removed with a rotovap - the resulting oil was vacuum distilled, discarding a large forerun of clear liquid, then yellow oil was collected. This was redistilled (vacuum/vigreux) and gave less than 30% yield of very clean P2P, the remainder distilled at >200° with same vacuum and was dark yellow and solidified after one week at 7°C. I guess it was the acid, too much maybe... Greetz A Pleased to meet you hope you get my name. But whats puzzlin you is the nature of my game!
		armageddon (Hive Bee) 08-21-04 16:22 No 526598				strange
						Another try was made, using 0.54 mol BzMgCl and, unfortunately, 30 grams sodium acetylacetonate and 24ml acetylacetone in ether (due to a brain glitch; the actonate salt was prepared in large quantity time ago, and the chemist thought he still had enough, until during the reaction, when he realized there was in fact only 30g left ). Maybe this accounts for the low yields, too - the bis addition product may have formed in significant quantity, but anyway: yield from this 0.54 mol run was only 13.4ml phenylacetone! (too disappointed to calculate any yield anymore ) And the hydrolysis as well as the vacuum distillation of crude product was done *very* carefully. And all traces of acid were removed by shaking the ethereal extracts of rxn twice with sat. sodium bicarbonate solution, followed by 2 washes with brine. Ether was stripped using a rotavap, the remainder was distilled under 20torr vacuum and P2P was collected between 108° and 118°C (note that steam temp. fell from >50°C to 24.5°C before it suddenly jumped to >100°C after a long while of heating - all fractions collected before were clear liquids with bp's below 70°C, therefore the ketone should've been distilled very sharply, with good separation from by-products). The remainder was flooded with 230ml H2O and steam distilled, hoping to reverse said dehydration process somehow, and is still in progress... Honestly, I don't think the dehydration due to traces of acid being present is the explanation for this wierd, high-boiling side product (which is sadly more the main product ). Maybe something was wrong with this huge batch of acetylacetone*Na. The Mg and ether shouldn't be the problem, they're both expensive quality grade reagents, the AA is tech grade (still very xpensive though ), and  - lo and behold - the BzCl used is analytical grade, well branded too , so the reactands are not the problem I think. The technique should be good enough to reproduce Bandil's results (at least getting the Grignard to start isn't any problem, and separating, washing and distilling organic liquids belongs to the few things SWIA as well as me are pretty familiar/skilled with). HELP! Are there any important things to consider (besides dryness of reaction, patience, attention, safety, precise measurement and practice of course ) when doing this reaction? Is the purity of the acetylacetonate salt essential for success maybe? I suspect that the salt that was used in the several miserable trials maybe contained traces of NaOH and therefore fucked up everything with "in-situ hydrolysis" while adding it? (just my thoughts; I'm a bit lost... ) Greetz A Ever took a shower with BzCl/Et2O solution?? Freshness for the whole day...
		Bandil (The Archetypical "Good Guy") 08-22-04 07:41 No 526738				Acetylacetonate purity
						Hi Armageddon! Sorry to hear about those poor yields First of all, the purity of the acetylacetonate is not one of the limiting factors. The highest yield I got was with brownish - ugly looking sodium acetylacetonate (overbaked in the oven - heh). It's obviously important that it's dry, but it seems that you got that covered. I think the problem is located in your acid hydrolysis / splitting technique. Heres what bothers me in your description: And the hydrolysis as well as the vacuum distillation of crude product was done *very* carefully. In the original article, they state that: This dehydration is a delicate operation; in some runs, only the splitting product, phenylacetone (IX) could be isolated I think that using dilute hydrochloric acid for the acid splitting operation will increase your yields. The reasoning behind this is that the hydrochloric/water layer will be less overall polar than a saturated ammoniumchloride/water layer. In theory this would allow more of the ether/product layer to mix with it, and thus increasing the water contents during the acid hydrolysis. This could push the equilibrium in the right direction. But more importantly: After stripping the ether and prior to distilling the ketone I heated the whole shebang to about 150°C at atmospheric pressure for about an hour, to facilitate the "deacetone'ation"(step IVb to IX). So next time, try treating it like you would with a real woman - rough Give it a whirl with this scheme: 1: React the grignard reactant with the sodium acetylacetonate. 2: Reflux for 4 hours. 3: Add dilute hydrochloric acid and stirr 4: Separate the organics and extract once more with ether 5: Wash the ether with aq. bicarbonate, twice with water, once with brine and finally dry it with whatever you have at hand. 6: Strip the ether 7: Heat the remaining organics to 120-150°C at atmospherical pressure for about one hour. 8: Distill the P2P under vacuum Regards Bandil Cocaine blows!
		Lilienthal (Moderator) 08-23-04 00:02 No 526846				Re: The Mg and ether shouldn't be the problem,
						The Mg and ether shouldn't be the problem, they're both expensive quality grade reagents,... Have you explicitly ultra-dried your ether? 'Quality grade' from the bottle might not be enough.
		armageddon (Hive Bee) 08-23-04 00:41 No 526859				Thanks guys
						Lilienthal: lemme cite from Bandil's last post here : "It's obviously important that it's dry, but it seems that you got that covered." (in fact I sometimes have problems with recycled ether becoming brown, i.e. developing peroxides, within 1 hour; although keeping it cooled and in the dark! I think its due to drying it too thoroughly... - and initiating the grignard reaction luckily is no problem for me) So I would say drying is not the issue. (remaining H2O is 0.001% with 4A mol.sieves, and I hope you don't think I'm not capable of adding enough drying agent and/or be patient enough, or that I don't use air-tight containers for drying!? ) Bandil: SWIA used dil. HCl for hydrolysis, but didn't heat (reflux?) the crude products after solvent removal. And I think this caused SWIAs dreaded results. Also after reacting the grignard complex with the AA salt, reflux was done for 9 hours (chemist was tired from supervising the reaction for hours and left lab to take a short nap, damn ether ). As said, no heating before vacuum distilling was applied. But I would think that during distillation, the acetone should spit off, too? Temperature of the liquid is well above 130°C if steam temp. is >110°C, and the vacuum should even facilitate the "de-acetonylation" (my all-around favorite "LeChatelier" again). But of course the extra 1h heating will bee included in future trials. Any more input before SWIA proceeds with his next try to reproduce the >60% yield result? If not: thanks anyway, your help at least gave me motivation Greetz, A Pleased to meet you hope you get my name. But whats puzzlin you is the nature of my game!
		Organikum (Wonderful Personality) 08-23-04 07:43 No 526919				Add some copperwire to your dry ether and...
						Add some copperwire to your dry ether and suppress peroxide formation this way. ATT.: This doesnt destroy peroxides which are already formed. so near, so far......
		moo (Hive Addict) 08-23-04 11:16 No 526921				It would be nice if peroxides could be ...
						It would be nice if peroxides could be detected by a brown colour, but I strongly doubt it. That would've made the KI-starch test papers and other tests for peroxides obsolete decades ago. It most likely is other impurities. So wash your ether properly before distilling it. I also disagree about the need for a condenser with a wide inlet. The trick is to get the reaction to start before most of the halide has been added. Then you can add more and maintain a gentle reflux all the way, without fear of sudden exotherms. A textbook gave the general directions for performing a Grignard on small scale, the instructions told to add at most 1/10 of the halide in the beginning. The crystal of iodine does wonders too. fear fear hate hate
		armageddon (Hive Bee) 08-23-04 12:35 No 526929				my problem is not ether but low yield! *lol*
						Impurities boiling at 34.5°C? And becoming brownish only when the ether is dried thoroughly? Being easily removed by washing with water/FeSO4? I doubt that. Especially as 2 bicarb washes followed by 1 water wash and 2 brine washes were done on crude product before solvent removal - thoroughly enuff? Think copper wire will do fine to prevent this from happening though. (thx) And Moo, I would not have stated it if I didn't knew about the danger of condensers not being able to handle huge amount of ether while still allowing for condensed ether to fall back, therefore leading to significant pressure buildup - and this is not a question of how much halide solution to add in the beginning; above a certain amount of solvent used, the reaction simply produces a lot of heat and vapor NO MATTER how careful the addition is done - maybe the wide inlet condenser isn't really necessary, but then a good cooling bath (ice/salt) is! I fail to understand the purpose behind advertising low security methods?! Greetz A Pleased to meet you hope you get my name. But whats puzzlin you is the nature of my game!
		moo (Hive Addict) 08-23-04 15:33 No 526945				Don't get me wrong, I don't mean to be an...
						Don't get me wrong, I don't mean to be an asshole. I've seen enough heated discussion here in the Hive lately , so  I'll give you my reasons for my opinions. My problem is with theories that seem unreasonable and unjustified. The FeSO4 procedure is a time-tested method for removal of peroxides. The presence of peroxides can be verified easily and I've seen it work (the KI-starch test paper was used for verification). I've also read my share of literature regarding reactions of peroxides and metal ions. My rationale is based on the fact that the peroxides from ethers are colourless. The colour has to originate somewhere else, even if the peroxides took part in the reactions. Surely the boiling point of the mixture is the boiling point of ether, but that doesn't mean small amounts of low-boiling impurities, for example acetone (bp 56.5°), won't come over with the ether. Acetone is a bitch to remove completely with water washes. Various salts dissolved in the water make it even less soluble in it. Acetone can also undergo an aldol condensation with another molecule of acetone, a process where water is eliminated and absorbing water is what molecular sieves are good for. When the condensation products condensate with more acetone you have polymerization that can lead to compounds with long conjugated chains. Such properties often make organic molecules coloured. Does that sound reasonable? Washing with bisulfite can be used to remove compounds bearing a carbonyl group, the same ones that can undergo an aldol condensation, were they acetone or something else. Maybe a few of those washes could give better results? Regarding the Grignard. I've never done a Grignard with BnCl, so I don't know how bad it is, although I've done a few Grignards with other compounds. What I said was what mostly a reaction to your post in the lab mistakes thread, but I surely didn't suggest being careless. That would be promoting insecure methods. What you said of an ice bath on hand is what I was after and I should've said so. I also promise you that I'll remember your advise if I ever do a Grignard with BnCl. However, it is very good to see people trying out new procedures and discussing them! fear fear hate hate
		armageddon (Hive Bee) 08-24-04 03:30 No 527025				my problem isn't...
						Well, the stupidity of my "stupid lab mistake" was using an improvised condenser connected to the rxn flask with glass tubing which was unfortunately not capable of allowing for reflux, due to the ether vapors pushing everything into the condenser instead of letting it fall back into flask. So in fact I used a condenser with narrow inlet and plop! - crash! - (cough, cry, gasp for breath and start swearing like a drunk, 80 year old sailor while wiping up the mess ) - and I can just tell that this doesn't happen if a normal condenser is used! And about my ether: it is OK! I can re-use it without problems, as long as I shake every discolored ether with FeSO4 soln. and then dry it again. And I don't know: every chemistry textbook tells that ether becoming brownish is due to peroxide development, and my ether if it has become brown responds pretty good to the usual techniques of peroxide removal... Left to say: stockpile ice cubes, dry your ether and be careful with adding the BzCl *slowly*. Good luck. Anyone got any ideas about hydrolysis of the "acetyl-P2P", before SWIA tries it a last time (tired of unseccessful grignards )? Greetz A Pleased to meet you hope you get my name. But whats puzzlin you is the nature of my game!
		armageddon (Hive Bee) 08-29-04 23:02 No 528176				stinky stuff
						BTW - SWIAs biggest problem smellwise is this strange high-boiling "side-product" from this grignard rxn. BzCl is nasty, but ceases to smell after a few days - but this stuff has a really disgusting smell of rotten eggs, citric acid and who knows what else... (not describeable) And even the glassware used still smells from that stuff, although several cleaning attempts with acids, lyes and even DCM, ether, toluene and ethyl formate were done! DON'T ATTEMPT TO DISTILL THAT STUFF EVEN WITH THE BEST VACUUM YOU CAN IMAGINE! At least I seriously wouldn't recommend it if you want to reuse your glassware... Greetz A Pleased to meet you hope you get my name. But whats puzzlin you is the nature of my game!
		Bandil (The Archetypical "Good Guy") 09-02-04 11:33 No 529120				Brown color
						I'd bet that the brown color originates from the sieves used. If they are stirred at more than 60 RPM (1 rotation per second), which is agonizingly slow, they will give of brown color, which can be removed by water wash. So I seriously doubt that you get peroxides in you ether that fast. Try stirring the sieves really slow in the ether and see if that clears up things! Regards Bandil Cocaine blows!
		armageddon (Hive Bee) 09-02-04 15:05 No 529155				weelll...
						Um, it seems you two (Moo and Bandil) were both right: SWIAs ether contained impurities as well as grinded sieves (washing with brine and redist. over NaOH did the trick), AND contained a little peroxide (potassium iodide/wheat starch) - but these were still present after dist.... Nevertheless SWIA wasn't able to reproduce Bandil's results and will probably stick with tin(2)chloride reduction of nitropropenes to prepare his perfumery ketones - less hassle with this oldschool route... Greetz A Pleased to meet you hope you get my name. But whats puzzlin you is the nature of my game!
		Bandil (The Archetypical "Good Guy") 09-03-04 07:42 No 529296				Other high boiling imputities!
						If you add the benzylchloride too fast, to the magnesium covered in ether, you will get quite an amount of 1,2-diphenylethane. This boils at 284°C, corresponding nicely with your findings. Read the first five lines from this (https://www.rhodium.ws/chemistry/phenylacetic.html) document. It describes the problem and solution quite nicely Regards Bandil Only one way leads to Valhalla - Running amok with TOTAL VIKING POWER
		armageddon (Hive Bee) 09-03-04 12:08 No 529333				thank you for clarifying on that!
						You're the best! SWIA is currently recrystallizing a large amount of rather useless bibenzyl from chloroform - nice colorless needles... once more: Thanks a lot! I already was beginning to think that the reused solvent was really the big problem - now I know at least what SWIAs mistake was, and maybe he'll try the rxn once more if I tell him about that. Greetz ...on my way to Valhalla!

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