01-03-02 17:21
No 252350
Has anyone ever tried using 3-chloroperoxy benzoic acid to form the epoxide of the isoalkene instead of the usual performic / peracetic. Here's the difference. The 3-chloroperoxy benzoic acid is a stable crystal that doesn't have to be prepared on the spot. It's generally a lot safer to handle and the work up looks the same on paper. There isn't any nasty waste to deal with, the side product is simply 3-chlorobenzoic acid. Yield is typically around 60%.
Isoalkene can be recovered easily for re-reaction.
I like to cook! . . . but some dudes in blue vests with yellow letters took my kitchen.
(Hive Bee)
01-03-02 18:55
No 252377
How OTC is this 3-chloroperoxy benzoic acid stuff anyhow? Is this from Rhodium's site? if not, you should post the whole written up procedure with references and maybe Rhodium'll add it to his collection! eh Rhodium?!
Does the crystal just get added straight or is it made into an alcoholic solution?
May The Source Bee With You....Always.
(Hive Addict)
01-03-02 19:36
No 252393
Yeah, 3-chloroperbenzoic acid is commonly used in labs for preparing epoxides. The yields are similar to other peroxyacids.
I think peracetic acid is much nicer for clandestine chemists as its easier to acquire than MCPBA and its almost as stable as MCPBA once prepared (especially when stored in fridge).
And, of course, performic is great for generating on the spot.
And potassium persulfate (Oxone) is a good choice for bees who don't have access to hydrogen peroxide and either acetic acid or formic acid.
(Old P2P Cook)
01-03-02 20:03
No 252412
The 3-chloroperoxy benzoic acid is a stable crystal
People I know generally refer to it as "meta-chloroperbenzoic acid" or MCPBA as Chromic calls it. Stability is a relative term, the stuff I have worked with had a tendency to fume off if it wasn't stored in a freezer.
that doesn't have to be prepared on the spot.
If you can buy MCPBA you can also buy premade peracetic acid or you can buy 100% formic acid or acetic anhydride and 50% H2O2 and easily prepare your own performic and peracetic acids.
It's generally a lot safer to handle
I'm not so sure about that.
There isn't any nasty waste to deal with, the side product is simply 3-chlorobenzoic acid.
Formic acid, acetic acid and their peracids would be seem to be much more biodegradable than meta-chlorobenzoic acid, just dump them down the toilet.
MCPBA is used when epoxide only is desired. For our purposes a mixture of glycol and epoxide is fine so there does not seem to be any advantage to using MCPBA.
(Hive Bee)
01-07-02 19:34
No 253828
Hey, I'm a youngin trying to help! :( im only 23!
I like to cook! . . . but some dudes in blue vests with yellow letters took my kitchen.
(Hive Prodigy)
01-07-02 19:40
No 253829
It's all about the information, not about the age of the presenter. Your information is much appreciated. So is the contrasting information presented by the others.
Issues need to be looked at from all views, or things easily become biased. The main reason we have so much information at our disposal here is because of one major Hive trait: it is a rare occurrance that we all agree on something. This brings out vast amounts of data, as it is necessary to back your statements.
This data is what is printed.
PrimoPyro
Vivent Longtemps la Ruche!
(Junior Service Representative)
01-08-02 11:22
No 254075
Hey, I'm a youngin trying to help! :( im only 23!
You still have a handful of years on myself. Being a teen-ager does have some advantageous, though...
PB