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All 25 posts   Subject: Wacker with 80% yield in 10min at RT with less Pd   Please login to post   Down

 
    Rhodium
(Chief Bee)
03-16-03 00:55
No 417436
User Picture  		      Wacker with 80% yield in 10min at RT with less Pd     

Doesn't anyone around here pay attention? This article has been mentioned repeatedly here for the last five years, and noone has even bothered to try it out yet? I have now HTMLized the article, which hopefully will correct this oversight by the Hive Collective.

Earlier posts on the topic:
1998 - Post 108395 (dormouse: "A Novel Approach to #3...aka..." Look, Ma, No Balloons" (Page 1) -spiceboy", Novel Discourse)
1999 - Post 104236 (purplxd: "Yield with Pd(AcO)2", Chemistry Discourse)
2000 - Post 18793 (Osmium: "Re: colloidal Pd soln. for wacker", Chemistry Discourse)
2002 - Post 252306 (sunlight: "Re: p-Benzo variation", Methods Discourse)

Abstract

An improved method for palladium(II)-catalyzed Wacker oxidation of cyclic and internal olefins is described. Addition of perchloric, sulfuric, nitric, or tetrafluoroboric acid to a chloride free solution of the Pd(II) catalyst gives rate enhancements of up to a factor of 50. The oxidation of cyclohexene to cyclohexanone, which was previously reported to give a 97% yield after 5 h, is now accomplished in 1 h quantitatively, with only one-third of the amount of Pd(II) used.

J. Org. Chem. 55, 2924-2927 (1990) (https://www.rhodium.ws/chemistry/wacker.improvement.html) 		 
 
 
 
    Sunlight
(Pioneer Researcher)
03-16-03 01:18
No 417448
       It's in my list     

Together with other procedures in the last years. I have little time. 		 
 
 
 
    SPISSHAK
(Hive Addict)
03-16-03 18:46
No 417632
       I think the reason people shyed away     

Is due to the fact that another variation of this reaction using palladium acetate was fickle and diffucult to duplicate succesful results with, I think the H2O2 Pd(ACO)2
method. 		 
 
 
 
    Sunlight
(Pioneer Researcher)
03-16-03 19:36
No 417648
       We know the benzo works     

I think it's not a serious reason, we know de benzo wacker works. Probably most people it's not very interested in research. 		 
 
 
 
    Triton
(Newbee)
03-16-03 20:08
No 417668
       Worth a try with O2?     

If one were to give it a wack with O2 and Palladium Nitrate is there any reason to believe that CuSo4 would not be an effective co-catalyst? 		 
 
 
 
    Rhodium
(Chief Bee)
03-16-03 23:45
No 417762
User Picture  		      Isosafrole Wacker - MDP2P in 69% yield
(Rated as: good read) 		    

This german article discusses the Wacker oxidation in detail, and tells us that anethole can be oxidized to 4-MeO-P2P in 55% yield and isosafrole to MDP2P in 69% yield. P2P can be had from 3-phenylpropene (allylbenzene), 1-chloro-3-phenylpropene and 2-chloro-3-phenylpropene in 76%, 25% and 22% repectively.

Katalytische Umsetzungen von Olefinen an Platinmetall-Verbindungen
J. Smidt
Angew. Chem. 71(5), 176-182 (1959) (https://www.rhodium.ws/pdf/isosafrole-wacker.pdf) 		 
 
 
 
    pupilage
(Hive Bee)
03-17-03 03:43
No 417853
User Picture  		      Worth a try with O2     

Triton I believe it was Ritter that sugested running O2 wacker slightly acidic. I started thinking about this same thing yesterday. Trying an O2 under slightly acidic conditions. Just need to get some CuSO4 now. Have plenty of CuCl though.
H2O2 is will shoot you into the side reactions creating polymers.
"Sometimes I sits and thinks, and sometimes I just sits." Satchel Paige 		 
 
 
 
    Bubbleplate
(Hive Bee)
03-17-03 04:02
No 417861
       Here's Another Wacker angle:     

I posted this before: Patent US3370073. It's your typical Pd Wacker EXCEPT that the H2O is added AFTER mixing the Safrole, Benzoquinone, and Pd catalyst all together upfront. Supposed to increase yield a bunch....
Once it gets a few degrees warmer outdoors, SWIM will be trying this out! 		 
 
 
 
    Rhodium
(Chief Bee)
03-26-03 02:50
No 421295
User Picture  		      Wacker oxidation of Propenylbenzenes
(Rated as: excellent) 		    

It has been found that the ratio of P2P to P1P formed in the wacker oxidation of various propenylbenzenes is proportional to the reaction temperature (the higher the temperature, the more P2P is formed), and when it comes to different ring substituents, it seems like electron-withdrawing substituents (CF3, Br, NO2 etc) favor the formation of P2P's, while electron-donating ones (OH, OCH3, NH2 etc) favor propiophenones. Isosafrole is likely to give around 50% of each extrapolated from this table.

Substituents - Propiophenone (P1P) - Phenylacetone (P2P)

4-CF3 - 5% - 95%  
4-H - 12% - 88%
4-CH3 - 21% - 79% 
2-OCH3 - 27% - 73%  
4-OCH3 - 33% - 66%  
2,4-OCH3 55% - 45% 
2,4,6-OCH3 70% - 30%



Representative procedure for the Wacker Oxidations of methylstyrenes:

A flask containing a suspension of palladium(II)chloride (35.4 mg, 0.2 mmol) and copper(I)chloride (198 mg, 2 mmol) in N,N-dimethylformamide (1 ml) and water (1 ml) was stirred under an oxygen atmosphere for 1 h. Alkene, 1b, (296 mg, 2 mmol) in N,N-dimethylformamide (0.5 ml) and water (0.5 ml) was added and the reaction mixture was stirred at 50°C for 24 h. The crude reaction mixture was applied directly to a pad of silica (ethyl acetate–hexane; 14) and the concentrated filtrate was analysed by 1H NMR. Purification by flash silica gel chromatography afforded ketones 2b and 3b (in the ratio 12.0) as a pale yellow oil (195 mg, 59%).

Regioselectivity in the Wacker Oxidation of Propenylbenzenes (https://www.rhodium.ws/pdf/wacker.propenylbenzenes.pdf)



I also found an article using PEG as Solvent for the Wacker Oxidation (https://www.rhodium.ws/pdf/wacker.peg.pdf)

 
 
 
 
    becomezen
(Hive Bee)
03-30-03 00:10
No 422359
User Picture  		      Rhodium please clarify !     

Do you remember Osmium's posts regarding analysis of post-wacker ketone ? I believe he found that it was roughly 85% MD-P2P and 15% MD-P1P ....

So what you are saying here , is that by running the reaction hotter , we can move the gradient even more towards the P2P side (perhaps 95% mdp2p , 5% mdp1p) ??

Also to clarify , the benzoquinone is there to provide oxygen , and bees have claimed success using pure O2...

If that is true , then what are your thoughts about running an O2 wacker even hotter ? I have seen some mention an upper limit of 40° , else the vessel will rupture.....

Assuming you had a vessel that could EASILY withstand the heat and pressure , at what level (temp and pressure) would this reaction be most optimized ?

I ask these questions b/c I have no formal chemistry education , and I am not able to talk "chemistry theory"

Please help !

Thanks cool
my guru once told me to "just be" , now I realize he meant "just bee" :) 		 
 
 
 
    Rhodium
(Chief Bee)
03-30-03 18:23
No 422539
User Picture  		      Wacker theory     

If that is true , then what are your thoughts about running an O2 wacker even hotter ? I have seen some mention an upper limit of 40° , else the vessel will rupture...

Temp limit: It depends on your vessel. Do not try to heat a vessel not designed for high pressure, or injury will likely result.

Analysis: The O2 wacker of safrole was analyzed by Ritter, not Osmium.

Isomer distribution: The article concerns the wacker oxidations of propenylbenzenes rather than allylbenzenes (as in isosafrole and not safrole itself). To improve the isomer distribution in the case of safrole, perhaps running the reaction cooler is the answer, but to answer that question definitely, someone with a more solid background than myself in physical organic chemistry should probably answer. 		 
 
 
 
    NeoSynthesis
(Stranger)
08-28-03 13:20
No 456149
       Survey Says.....?     

Hiya Bubble - btw.. forgot to thank  you for your much-appreciated detailed reply to my post on Wacker Ox. Anyways.. curious to know if anyones tried this variation, and if so, with what results?

cheers beez 		 
 
 
 
    Rhodium
(Chief Bee)
02-13-04 15:56
No 488370
User Picture  		      Pd(II)/O2: Terminal Alkenes to Methyl Ketones
(Rated as: excellent) 		    

Novel Palladium Catalytic Systems for Organic Transformations
Takahiro Nishimura, Sakae Uemura
Synlett 201-216 (2004)
DOI:10.1055/s-2004-815412

Abstract
This article summarizes the results of our recent studies on palladium catalytic systems for the oxidation of alcohols and beta­alkenes using molecular oxygen or air together with several successful attempts to make the system recyclable from the viewpoint of ‘green and sustainable chemistry’.


5.0 Palladium(II)-Catalyzed Oxidation of ­Terminal Alkenes to Methyl Ketones Using Molecular Oxygen

Palladium-catalyzed oxidation of alkenes to methyl ketones has been developed in synthetic organic chemistry as well as in industrial processes using PdCl2 and CuCl2 or Cu2Cl2 as catalysts in acidic water under an oxygen atmosphere.23,24 However, this catalytic system is highly corrosive because of its acidic conditions and may cause the formation of chlorinated by-products in some cases. To overcome such drawbacks, halide-free catalytic systems have also been widely investigated.25

On the other hand, Mimoun and co-workers have reported that a Pd(II)-OOH species undergoes an oxygen transfer to terminal alkenes via peroxypalladation to afford methyl ketones as shown in Scheme 12.26


Scheme 12

An example of the palladium-catalyzed oxidation of cyclopentene to cyclopentanone in ethanol using molecular oxygen as the sole reoxidant was reported by Takehira and co-workers in 1985.9a They also proposed the formation of a Pd(II)-OOH species from palladium, ethanol, and oxygen.9a,27

In the course of our studies on the aerobic oxidation of alcohols described in previous sections, we proposed the in situ formation of a Pd(II)-OOH species as well as H2O2. This assumption prompted us to check whether this Pd(OAc)2/pyridine/O2 catalytic system is applicable to the oxidation of terminal alkenes based on Scheme 12.28 In fact, the treatment of 1-dodecene in toluene (5 mL) and 2-propanol (5 mL) in the presence of 5 mol% Pd(OAc)2 and 20 mol% pyridine at 60°C for 6 hours under an oxygen atmosphere afforded the expected 2-dodecanone (70% GLC yield, Scheme 13). Other simple terminal alkenes were converted to the corresponding methyl ketones in good yields under the same conditions. Interestingly, 10-un­decen-1-ol was mainly transformed to 11-hydroxy-2-undec­anone in 71% yield showing that a terminal double bond was oxidized much faster than a hydroxyl group. It is noteworthy that this oxidation system was applicable only to terminal alkenes, and not to internal ones.


Scheme 13

A plausible reaction pathway for this oxidation using Pd(OAc)2/pyridine/2-propanol/O2 catalytic system is shown in Scheme 14, where two catalytic cycles operate. One cycle is the oxidation of 2-propanol (cycle A) to give acetone and a Pd(II)-H species, the latter of which is transformed to a Pd(II)-OOH species by the reaction with oxygen. The Pd(II)-OOH species reacts with an alcohol to give an alkoxypalladium(II) species as well as H2O2.9 This Pd(II)-OOH species also reacts with alkenes via peroxypalladation (Scheme 12) in another catalytic cycle (cycle B) to produce methyl ketones and a Pd(II)-OH species which reacts with H2O2 to reproduce the Pd(II)-OOH species.


Scheme 14



References

[9a] Strucul G. Ros R. Michelin RA. Inorg. Chem. 21, 495 (1982) (See Below)
[9b] Takehira K. Hayakawa T. Orita H. Chem. Lett. 1835 (1985)
[9c] Hosokawa T. Murahashi S.-I. Acc. Chem. Res.  23, 49 (1990) (See Below)

For recent reviews see:
[23a] Tsuji J. Palladium Reagents and Catalysis  Wiley; New York: 1995.  p.19-30 
[23b] Jira R. In Applied Homogeneous Catalysis with Organometallic Compounds   Cornils B. Herrmann WA. VCH; New York: 1996.  p.374-393 
[23c] Monflier E. Mortreux A. In Aqueous-Phase Organometallic Catalysis   Cornils B. Herrmann WA. Wiley-VCH; New York: 1998.  p.513-518 
[23d] Takacs JM. Jiang XT. Curr. Org. Chem. 2003, 7: 369

Recent examples of Wacker oxidation of higher alkenes see:
[24a] Smith AB. Cho YS. Friestad GK. Tetrahedron Lett. 39, 8765 (1998) (See Below)
[24b] Mohammedi O. Chemat F. Brégeault J.-M. Eur. J. Org. Chem. 1998, 1901
[24c] Karakhanov E. Maximov A. Kirillov AJ. Mol. Catal. A: Chem. 2000, 157: 25
[24d] Yokota T. Sakakura A. Tani M. Sakaguchi S. Ishii Y. Tetrahedron Lett. 2002, 43: 8887
[24e] Choi K.-M. Mizugaki T. Ebitani K. Kaneda K. Chem. Lett. 2003, 32: 180

[25a] Bäckvall J.-E. Hopkins RB. Tetrahedron Lett. 1988, 29: 2885
[25b] Bäckvall J.-E. Hopkins RB. Grennberg H. Mader MM. Awasthi AK. J. Am. Chem. Soc. 1990, 112: 5160
[25c] Yokota T. Fujibayashi S. Nishiyama Y. Sakaguchi S. Ishii Y. J. Mol. Catal. A: Chem. 1996, 114: 113
[25d] Kishi A. Higashino T. Sakaguchi S. Ishii Y. Tetrahedron Lett. 2000, 41: 99
[25e] Monflier E. Blouet E. Barbaux Y. Mortreux A. Angew. Chem. Int. Ed., Engl. 1994, 33: 2100
[25f] Monflier E. Tilloy S. Fremy G. Barbaux Y. Mortreux A. Tetrahedron Lett. 1995, 36: 387
[25g] Monflier E. Tilloy S. Blouet E. Barbaux Y. Mortreux A. J. Mol. Catal. A: Chem. 1996, 109: 27
[25h] Hirao T. Higuchi M. Hatano B. Ikeda I. Tetrahedron Lett. 1995, 36: 5925
[25i] Higuchi M. Yamaguchi S. Hirao T. Synlett 1996, 1213
[25j] ten Brink G.-J. Arends IW. Papadogianakis G. Sheldon RA. Chem. Commun. 1998, 2359
[25k] ten Brink G.-J. Arends IW. Papadogianakis G. Sheldon RA. Appl. Catal. A 2000, 194-195: 435
[25l] Ito H. Kusukawa T. Fujita M. Chem. Lett. 2000, 598

[26a] Mimoun H. Charpentier R. Mitschler A. Fischer J. Weiss R. J. Am. Chem. Soc. 102, 1047 (1980) (See Below)
[26b] Roussel M. Mimoun H. J. Org. Chem. 45, 5387 (1980) (See Below)
[26c] Mimoun H. Angew. Chem. Int. Ed. Engl.  21, 734 (1982)

[27] Takehira K. Hayakawa T. Orita H. Shimizu M. J. Mol. Catal. 53, 15 (1989)

[28] Nishimura T. Kakiuchi N. Onoue T. Ohe K. Uemura S. J. Chem. Soc., Perkin Trans. 1, 1915-18 (2000) DOI:10.1039/b001854f (Free!)


[9a]Preparation and oxygen-transfer properties of novel palladium(II) and platinum(II) hydroperoxo and alkylperoxo complexes
Strukul, Giorgio; Ros, Renzo; Michelin, Rino A.
Inorganic Chemistry (1982), 21(2), 495-500 (1982) (https://www.rhodium.ws/pdf/pd-pt-hydroperoxo-complexes.pdf)

Abstract
Mononuclear hydroperoxo and tert-butylperoxo complexes RML2OOR1 (L = 1/2 diphosphine or monophosphine; M = Pd, Pt; R = H, Me3C; R1 = activated alkyl) were prepared by condensation reactions of RML2OH with R1OOH. Whereas Me3COOH reacts in all the cases tested, with H2O2 the preparation reaction is sensitive to the nature of R. These compds. behave as typical O-transfer agents, reacting with PPh3, CO, NO, and PhCHO. trans-CF3Pt(PPh2Me)OOCMe3 oxidized terminal olefins to the corresponding Me ketones.
____ ___ __ _

[9c]New aspects of oxypalladation of alkenes
Hosokawa, Takahiro; Murahashi, Shunichi
Accounts of Chemical Research 23(2), 49-54 (1990) (https://www.rhodium.ws/pdf/alkene.oxypalladation.pdf)

Summary: A review with 54 refs. dealing with mechanistic and synthetic aspects of intramol. oxypalladation and acetalization of alkenes.
____ ___ __ _

[24a]Convenient Wacker oxidations with substoichiometric cupric acetate
Amos B. Smith, III, Young Shin Cho and Gregory K. Friestad
Tetrahedron Letters 39(48), 8765-8768 (1998) (https://www.rhodium.ws/pdf/wacker.o2.cupric.acetate.pdf)
DOI:10.1016/S0040-4039(98)01992-3

Abstract
A modification of the Wacker oxidation of terminal olefins to methyl ketones using substoichiometric amounts of Cu(OAc)2 as a redox shuttle reagent is described. The modified procedure is generally high yielding despite reduced levels of copper salt and convenient. Importantly, in a problematic case, the conditions suppressed acidic hydrolysis during oxidation of substrate (+)-5 containing an acetonide. Has been mentioned in Post 108566 (dormouse: "improvements in wacker rxn.  -neocelsis", Novel Discourse)
____ ___ __ _

[26a]Palladium(II) tert-butyl peroxide carboxylates. New reagents for the selective oxidation of terminal olefins to methyl ketones.
Mimoun, Hubert; Charpentier, Robert; Mitschler, Andre; Fischer, Jean; Weiss, Raymond
Journal of the American Chemical Society 102(3), 1047-54 (1980) (https://www.rhodium.ws/pdf/wacker-pd-h2o2-2.pdf)

Abstract
The synthesis and characterization of new Pd(II) tert-Bu peroxide carboxylates with the general formula [RCO2PdOO-tert-Bu]4 (R = Me, CCl3, CF3, C5F11) are described. X-ray data gave the crystal and mol. structures of [Cl3CCO2PdOO-tert-Bu]4 (I). The 4 Pd atoms of I are coplanar and are located approx. at the corners of a square. Four trichloroacetate bridging anions are alternatively above and below this square. I are highly efficient reagents for the selective stoichiometric oxidation of terminal olefins to Me ketones at ambient temperature, and catalysts for the ketonization of terminal olefins by tert-Bu hydroperoxide. A mechanism involving a 5-membered pseudocyclic peroxymetalation of the coordinated olefin was suggested.
____ ___ __ _

[26b]Palladium-catalyzed oxidation of terminal olefins to methyl ketones by hydrogen peroxide
Roussel, Michel; Mimoun, Hubert
Journal of Organic Chemistry (1980), 45(26), 5387-90 (1980) (https://www.rhodium.ws/pdf/wacker-pd-h2o2-1.pdf)

Abstract
Pd(II) complexes are very efficient catalysts or the selective oxidation of terminal olefins RCH:CH2 (R = n-hexyl, n-octyl, n-decyl, AcOCH2) to RCOMe by H2O2. HOCH2CH:CH2 gave a mixture of HCO2H, AcOH, and EtCO2H. This reaction is best carried out in solvents such as tert-BuOH or AcOH, and requires a large excess of H2O2 with respect to the olefin in order to achieve a nearly complete conversion of the substrate without precipitation of metallic Pd. The general trend of this reaction suggested a mechanism very similar to that previously shown for the oxidation of terminal olefins by Pd(II) tert-Bu peroxide carboxylates, and involving a pseudocyclic hydroperoxypalladation of the coordinated olefin.
The Hive - Clandestine Chemists Without Borders 		 
 
 
 
    Scooby_Doo
(Hive Bee)
02-16-04 07:15
No 488987
       GC's of standard benzo DMF wacker showed the...     

GC's of standard benzo DMF wacker showed the reaction to be finished around 3.5 hour mark. There was no yield increase with the extra time. On saying that, it really also depends on what your starting temp is, and how large the reaction. (The larger may be a little quicker due to the higher heat generated by the reaction.) 		 
 
 
 
    Rhodium
(Chief Bee)
08-13-04 17:06
No 525284
User Picture  		      Chloride-Free Aerobic Wacker Oxidation
(Rated as: good read) 		    

Wacker oxidation of cyclohexene in the presence of Pd(NO3)2/CuSO4/H3PMo12O40
Marisa S. Melgo, Alexandra Lindner and Ulf Schuchardt, Applied Catalysis A: General, Vol. 27x, p. xxx (2004) - Article in Press
DOI:10.1016/j.apcata.2004.06.035



Abstract
The Wacker oxidation of cyclohexene to cyclohexanone, using the chloride ion-free catalytic system Pd(NO3)2/CuSO4/H3PMo12O40, was investigated at different air pressures, temperatures, and catalyst concentrations. The results show that this system is very efficient and highly selective. After 1 h of reaction at 80°C and an air pressure of 50 bar, a conversion of 80%, with a turnover frequency of 260 h−1, and a selectivity of more than 99% for cyclohexanone was obtained. Using aqueous hydrogen peroxide and no external pressure, the oxidation was more rapid, giving 80% conversion already after 30 min and 95% conversion after 60 min without the formation of any byproducts.
The Hive - Clandestine Chemists Without Borders 		 
 
 
 
    Dope_Amine
(Hive Bee)
10-20-04 09:05
No 536765
User Picture  		      Perchloric tallyWACKER
(Rated as: excellent) 		    

Hi Y'all!  Someone is willing to do research.

Perchloric Wacker

     The improved wack was done by my favorite harry primate: Max the bonobo, and no joke, he seriously went ape-shit over the results.  Not only was the molar % of Pd greatly reduced from previous times, but the amount of benzoquinone too was reduced which makes life a lot easier.   As many familiar with the benzo-wack know, the work-up is equally as important as the rxn for a pleasant outcome, so please take note of those details below or Max will throw some poop at you.


Based on the improved wacker article on Rhod's page:

 120 g safrole (.74 moles)
 1.66 g Pd(OAc)2 (1 molar %)
 72 g benzoquinone (90 molar %)
 19 g 70% perchloric acid
 440 mL acetonitrile
 60 mL water



     Pd(OAc)2 was stirred for 30 minutes (to ensure good dissolution) w/350 mL AcCN in a 3 neck 2 L rb.  Benzoquinone was added (endothermic), the funnel washed with 50 mL AcCN, and the solution was allowed to stir until temp climbed back up to ambient (~1 hr).  Perchloric acid was then gently poured in (.24 M at midpoint of saf. addition).  Flask was fitted with a condenser (not really necessary) and an addition funnel with 120 g safrole dissloved in 40 mL AcCN.  Addition was started at a healthy drip rate.  The flask heated up within minutes, but no condensate was ever noted in the condenser.  The flask was allowed to stir until it returned to room temperature (~2 hours).


Work-up:

     The reaction mix was filtered through an inch of packed, solvent-wetted celite (makes filtration very easy).  The filtrate was then poured into a 4 L separatory funnel and shaken with (.45 L conc. HCl + 200 mL brine + 800 mL water).  This is then extracted with 600, 300, 200, and 100 mL DCM, taking very great patience to allow a full as possible separation and with light agitation as it drains to knock DCM globs to the bottom.  Care was also taken to not allow the crud at the bottom edge of the water layer into the pooled DCM.  The DCM was then washed once with 500 mL sodium bicarbonate.  This is the main wash where product will be lost if not careful, so patience with the separation is very beneficial as well as maybe the addition of some brine (50-100 mL).  One can check that they got most all of their product by making sure that the total pooled DCM adds up to close to 1200 mL (DCM) + 110 mL ('tone) + ~150 mL more DCM (used to wash the rxn flask, filter funnel, and filter flask) or, alternatively one could back extract with a bit of DCM.  Next, the DCM/'tone is washed once with 500 mL brine and twice with 10% NaOH (again care and patience).  The DCM/'tone is then dried with mag. sulfate and distilled (24/40 regular vac. distill set-up pulls faster and potentially with more theoretical plates than a short path).  There is no noticable forerun of saf/isosaf, just straight bright neon-yellow/clearish 'tone (118 g) and a bit of black crap left in the flask.  Yield: 89.5%  The H'nMR looked very good, very clean. 

If only ya didn't have to do the washes, I think this modified wacker would get up to 95%.  Might asarone do as well or would the perchloric acid cause some issues?  Hmmm.....
something for your mind....... 		 
 
 
 
    XrLeap
(Hive Bee)
10-22-04 12:19
No 537129
       Hi dope_amine, good work.     

Hi dope_amine,

good work. may swim know what is the CAS of Pd(OAc)2? Is it 14588-08-0?

SWIM just wanna make sure he gets the correct item as palladium is more expensive than gold in SWIM's area.:)
oops i did it again 		 
 
 
 
    Dope_Amine
(Hive Bee)
10-23-04 01:27
No 537235
User Picture  		      Jeez, I thought I woulda gotten more of a...     

Jeez, I thought I woulda gotten more of a reaction from people than this....

According to: [url= http://chemfinder.cambridgesoft.com the CAS # for palladium acetate is 3375-31-3.

Sometimes it's called palladium acetate trimer.  The "trimer" is just extra info, it's still the same stuff.

I would think it would be a bit cheaper that PdCl2 since the molecular weight is higher.

I wish I knew of a way to easily extract the catalyst from that nasty benzo/hydroquinone rxn mixture.
something for your mind....... 		 
 
 
 
    XrLeap
(Hive Bee)
10-23-04 07:36
No 537275
       Hehe     

Hi Dope_Amine,

SWIM is certainly feeling great with this posting, allowing SWIM to say thank you.

You are great and SWIM will plan to reproduce the work done.

Just a question, what was the temperature range that 'tone was distilled over? SWIM normally does it over 25 degrees range.....
oops i did it again 		 
 
 
 
    Dope_Amine
(Hive Bee)
10-23-04 11:27
No 537285
User Picture  		      It depends on your vac.     

It depends on your vac.  Max's is somewhat crappy right now so it came over at ~130 +/-5 °C 

These questions are kinda more dependant from person to person and since I think you are mostly going to ask q's that only serve you, I think pm is the best way to converse.  Reduce the crap that peope have to filter when going through TFSE ya know. 

Anywayz, typically if you have good 'tone, it is yellow.  Double distilled 'tone is clear.  So, clear-ish/yellow 'tone from the first distillation would bee a good sign.  During distillation, normally with the regular benzo wack, one gets a few mL's of completely clear isosaf b4 the temp climbs a bit and the 'tone comes over.

Not the case with the perchloric version....tongue
something for your mind....... 		 
 
 
 
    bbeeasheets
(Hive Bee)
11-02-04 04:25
No 539165
       please clarify for newbie this statement     

from the workup
"The filtrate was then poured into a 4 L separatory funnel and shaken with (.45 L conc. HCl + 200 mL brine + 800 mL water"

does this mean all at once? or each of those separately? i know this is a stupid question, but .....i am new after all!

i am planning on testing this thursday....since my performics appear to suck on yields

thanks for the awesome research Dope_Amine! 		 
 
 
 
    Dope_Amine
(Hive Bee)
11-02-04 06:00
No 539176
User Picture  		      Yea, all at once. One of the biggest problems...     

Yea, all at once. 

One of the biggest problems with the benzo wacker is the work-up.  It can totally fuck your yields.  I absolutely do not recommend trying to scale up the 'tone without scaling up the washings also.  What is stated is barely enough to get it well clean enough for a good distillation- mainly refined by doing extra washes and realizing that they didn't do all that much.  In the future, it might bee decided to get rid of the bicarb wash altogether, cuz that's a real motherfucker on da yield....  Prolly, next time it'll bee dropped and we'll see how it goes.  If you wanna give it a try, then get rid of the bicarb wash and maybee do an extra brine wash or maybee not.  Then let us know.  Otherwize, we'll have to wait a while for the bonobo to do it (he's a busy primate).tongue
something for your mind....... 		 
 
 
 
    Sunlight
(Pioneer Researcher)
11-10-04 03:33
No 540736
       good work     

Congratulations, fine to read your work. A question about the distillation, in the regular benzo wacker with DMF, the range of temp is wide, about 25 C, and the distillate contains crystalline solids. The yield in the conversion of that ketone to aminee is low, so the real yield of ketone is not really good, 50-60 %. In your experience did you observe this winde range of temp in distillation and solid impurities or the rxn seems more clean ? 		 
 
 
 
    Dope_Amine
(Hive Bee)
11-12-04 02:28
No 541140
User Picture  		      Thanks Sunlight! No solid impurities were...     

Thanks Sunlight!

No solid impurities were noted. There wasn't much left in the distilling flask at all.  The temp range that it came over was ~10 °C. Unfortunately, the H-nMR taken was from darker yellow residue on the side of the distilling flask (Max was being a cheap-skate, won't do that again).

Was the DMF 'tone that you speak of that blue kind?  This 'tone was a very especially clear bright yellow.

I'm sure Max the bonobo would have done more tests by now if it weren't for the fact that his benzo supply has run dry...
something for your mind....... 		 
 
 
 
    Sunlight
(Pioneer Researcher)
11-13-04 20:08
No 541420
       Yellow     

It has been said reppeated times that ketone from benzo is fluorescent green, you can see pictures in Rhod's page, but what I saw was a yellow ketone, not specially different in colour from the ketone coming from performic.
Your experience sounds promising. 		 
 

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