Possible Peracetic Revision

[Rhodium]

After mixing H2O2, Acetic acid and H2SO4, the mixture must be allowed to stand for at least 12h for the peracetic acid to form.

I really think someone should try to substitute MEK for the acetone in both the peracetic and performic reaction and report back if there was any difference in workup/yield using that solvent. It is VERY similar to acetone, but with the difference that it doesn't form a crystalline peroxide easily.

[noj]

On a second attempt at the peracetic following the writeup at Rhodium's site, I ended up with an extremely viscous fluid that looked like the ketone, but had little smell. It was too thick. I had to dilute with methanol to pour it out at room temperature. It also would not aminate. The reaction wasn't buffered and acetone was used as a solvent, albeit less than the writeup purposed. A crystalline substance appeared in the condenser that would only rinse out with acetone. The peracid was allowed to form for 16 hrs before use. I'm not certain what is going wrong.
No One's Jurisdiction

[Rhodium]

Have you performed the H2SO4 hydrolysis of the crude reaction product, done the extraction and distilled the oil?

If so, what color is it, what temp/pressure did it distill at, and what was your yield? How thick is it?

[goiterjoe]

This is the first time I've read this thread, and I think I missed out on a lot of good information.

Semtexium, thanks for confirming my results.  SWIM ended up with an oil that boiled like ketone, but became syrupy in the freezer.  it didn't aminate correctly, instead resulting in a plasticized looking substance that was thrown out. 

Rhodium, wouldn't substituting MEK for acetone still result in MEK peroxide being formed which is also a powerful sensitive explosive?
Sed quis custodiet ipsos custodes?

[terbium]

Rhodium, wouldn't substituting MEK for acetone still result in MEK peroxide being formed which is also a powerful sensitive explosive?
From personal experience, the MEK hydroperoxide polymer is a very sensitive explosive. I have not seen it in solid form though. Perhaps Rh's point is just that the MEK peroxide doesn't drop out of solution as easily and is thus more likely to stay diluted in solution where it is less dangerous.

[PoohBear4Ever]

Check out this info on acetone peroxide:

http://www.xinventions.com/main/pyro/ap.htm

I wonder what the maximum amount of this could likely be produced from the peracetic rxn, and what amount of energy such an amount possesses.  If we are only talking about loosing an arm or a leg, no big deal; however, I am somewhat attached to the rest of my body   .

PB

[Rhodium]

Yes, my point is to use MEK instead of acetone because MEK peroxide (while still being as explosive as acetone peroxide) will not crystallize out of the solution, and thus will be much less likely to detonate from impact/friction, as it stays diluted in the organic solvents.

[noj]

Rhodium, yes. Everything as written on your review of peracids. The post rearrangement product was thick, like motor oil, but looked fluorescent yellow. It came over 25° higher than safrole under vacuum, over a 10° range. My only guess would be the wood bleach peroxide was not pure. Will try it again in a few days with reagent grade chemicals. Will also try buffering.
No One's Jurisdiction

[Osmium]

> The post rearrangement product was thick, like motor oil,
> but looked fluorescent yellow. It came over 25° higher
> than safrole under vacuum, over a 10° range.

and

> ended up with an oil that boiled like ketone, but became
> syrupy in the freezer.  it didn't aminate correctly,
> instead resulting in a plasticized looking substance

You guys didn't hydolyse/rearrange for long enough, sounds like the glycol to me.

[noj]

So perhaps one should go longer than the 2hrs? A stronger acid solution?
No One's Jurisdiction

[PoohBear4Ever]

From swims experience, it seems that while 2 hours of 75-80C is hot enough for performic h2so4 rearrangements, SWIM thinks it might be better for cleaving the acetyls with a longer/hotter reaction.  SWIM always ran his a little hot, but one time, exactly 2 hours, carefully monitored at 75-80C temps, yielded some obviously fucked up ketone, which was aminated for shits and giggles, and yielded NOTHING.

Isn't this what unnil was just talking about?  I wonder what parameters he uses when wishing to aminate for reasons other than "shits and giggles?"


PB

[Chromic]

I made a post on a peracetic acid in DCM... it works wonderfully. It is necessary to give the H2O2/acetic acid nearly a week to come to equilibrium (mind you, it stores very well in a fridge, make up extra...).  Ever mixed GBL/water together? Ever noticed how long it takes to come to equilibrium of GHB/GBL/H2O? (nearly a week...) Anyways, I never had success on the peracetic until I had some vidid dreams of an old man that guided me towards success. Try it, you won't be displeased.

[goiterjoe]

What would be the recommended length of acid reflux hydrolysis then?  It's been a while since swim last did this, but he remembers letting it go for 2 hours.  Would a 2x stronger acid concentration with a 3h reflux be good or excessive?
Sed quis custodiet ipsos custodes?

[goiterjoe]

would the glycol be fairly soluble in methanol or a methanol/nitromethane mix?  And if the plasticized post amination product were still around somewhere, is there a simple test that could be performed on it to see if was indeed the glycol that was used as the starting material?
Sed quis custodiet ipsos custodes?

[Osmium]

TLC.

[unnilhexium]

The original Fugasawa/Deguchi performic synth called for a 3 hour rearrangement, but now every synth I see calls for 2 hours.  Whose idea was it to shorten the time?  Was the shorter time shown to yield more ketone(or maybe just more distillate?)?  SWIM believes that the longer time would yield purer ketone, as it seems a lot of the glycol is left over after only 2 hours.
106

[Rhodium]

I don't believe there was anyone in particular who told us to shorten the acid reflux time (except perhaps Ritter in

Post 41983 (missing)

(Ritter: "Re: Modified Performic", Methods Discourse)).

[unnilhexium]

That damn ritter thinks he knows everything   LOL ritter, you are my idol.  SWIM just tried lengthening the h2so4 reflux in a peracetic dream, to 2 hours and 20 minutes.  The result: narrower distillation temp range, and a more flourescent color to the ketone.  The subsequent amination dream failed, but SWIM is certain that the failure was due to other factors(problems with amalgamation, and using the MeOH/MeNO2 azeotrope instead of pure MeNO2).  SWIM is going to go for the full 3 hours next time.  In that post, ritter says that methanol is not necessary, so without the use of methanol, the reaction would run considerably hotter, and 2 hours probably would be sufficient for the rearrangement to take place, IMO.   
106

[goiterjoe]

SWIM decided to be ballzy and test out the plasticized crystals, and sure enough they worked they had a delayed taste to them, but then the taste was undeniable, and the effects were definitely undeniable(extreme empalthy, dilated eyes in light, talkative, loss of appetite, etc.).  SWIM guess this could be the beginning of a new era, as he can now say that the peracetic in DCM definitely works.  it's just a question of where the yeilds got so wrong.  as was said earlier, the acid hydrolysis should have been run for at least 3 hours instead of barely 2.
If Pacman had influenced us, we'd run around dark rooms eating pills and listen to repetitive music

[foxy2]

Thought I would add this reference to a similar epoxidation.

Patent EP1140788

The epoxidation of an optionally substituted trans-cinnamic alcohol of formula:

to give an epoxide of formula la can conveniently be carried out using a suitable epoxidizing agent, for example, vanadic anhydride and hydrogen peroxide, vanadium (acetylacetonate) 2 and tert-butyl hydroperoxide, or a peroxy acid such as perbenzoic acid, m-chloroperbenzoic, peracetic acid, pertrifluoroacetic acid or mono-or di-peroxy-phthalic acid. The reaction can be carried out in any suitable solvent or combination of solvents, for example, in a hydrocarbon, a halogenated hydrocarbon, a linear or branched ether, a carboxylic acid, or an ester. Specific solvents include benzene, toluene, chloroform, methylene chloride, diethyl ether, dioxane, acetic acid, and ethyl acetate. Preferably the reaction is carried out in methylene chloride or ethyl acetate. More preferably in methylene chloride. The reaction can be carried out at any suitable temperature from the freezing point to the reflux temperature of the reaction mixture. Preferably the reaction is carried out at a temperature in the range of about 0 C to about 50 C. More preferably at a temperature in the range of about 5 C to about 25 C.

United States patent 5,068,433 and related United States patent 5,391,735 disclose that an epoxide of formula Ib can be prepared from trans-cinnamic alcohol using a suitable oxidizing agent, for instance vanadic anhydride and hydrogen peroxide, or a peroxy acid such as, e. g., perbenzoic acid, m-chloroperbenzoic, peracetic, mono-or di-peroxyphthalic, or peroxy-trifluoroacetic acid. At Example 1, these patents specifically exemplify the preparation of an epoxide of formula Ib by the oxidation of trans-cinnamic alcohol with m-chloroperbenzoic acid. The oxidation of trans-cinnamic alcohol with m-chloroperbenzoic acid was also reported by P. Melloni et al. Tetrahedron, 1985,41, no. 7,1393-1399.
m-Chloroperbenzoic acid is expensive to use on a commercial scale. Thus, a different epoxidation reagent would be preferred for the commercial scale production of a compound of formula (A). Studies with mono-peroxy-phthalic acid have shown that this reagent can be used to prepare epoxide Ib on a commercial scale. However, the preparation of mono-peroxy-phthalic acid from phthalic anhydride and hydrogen peroxide is time consuming. Additionally, the epoxidation reaction with mono-peroxy-phthalic acid generates a large amount of solid phthalic acid by-product that must be filtered from the product mixture. This filtration step is time consuming and generates a large amount of aqueous and solid wastes. Thus, m-chloroperbenzoic acid and mono-peroxy-phthalic acid are not ideally suited for the commercial scale epoxidation of trans-cinnamic alcohol.

It has been discovered that the epoxidation of cinnamyl alcohol can conveniently be carried out on a commercially scale using peracetic acid. Peracetic acid is less expensive and, as a liquid, is easier to handle on a large scale than m-chloroperbenzoic acid, which is a solid. Additionally, the use of peracetic acid reduces the time required for preparing epoxide Ib, by eliminating the need to prepare mono-peroxy-phthalic acid; peracetic acid also substantially reduces the amount of aqueous and solid waste generated by the epoxidation reaction compared to the reaction with mono-peroxy-phthalic acid.

Accordingly, the invention provides a method for preparing an epoxide of formulala:

comprising oxidizing a corresponding optionally substituted trans-cinnamic alcohol with peracetic acid. The epoxide la is highly sensitive to decomposition by strong acids.

Commercial peracetic acid is stabalized with sulfuric acid. Accordingly, the peracetic acid should be treated with a suitable base (e. g. sodium or potassiun acetate) prior to use; or the reaction can conveniently be run in the presence of a suitable solid base (e. g. sodium or potassium carbonate). Preferably, the reaction is carried out on a commercial scale.

Preferably, the reaction is carried out in methylene chloride and at a temperature below about 30 C.


Example 1. (2RS, 3RS)-2,3-Epoxy-3-phenylpropanol (I).

Sodium carbonate (224 g) and trans-cinnamyl alcohol (200.0 g) were mixed with 2L of methylene chloride. a slow nitrogen sweep was maintained through the vapor space of the flask and the mixture was cooled to 15-20 C with a cold water bath. Peracetic acid solution (35%, 381.2mL) was added over a 3 hour period, maintaining the internal temperature below 25 C. After the peracetic acid addition was complete, the mixture was stirred for 2-3 hours until complete, as shown by HPLC analysis. The mixture was cooled to 10 C with an ice bath, and a solution of sodium sulfite (160g) in 1200 ml water was added slowly over 90 minutes, keeping the temperature below 30 C. The phases were separated and the aqueous phase was extracted with methylene chloride (200 mL) to give a solution of the title compound.
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