Re: Promoting decarboxylation

[EMAIL PROTECTED] (David Naugler) wrote in message news:<[EMAIL PROTECTED]>...
> Uncle Al <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>...
> > David Naugler wrote:

> > > This query was also posted to sci.chem

> > > Hi,

> > > I'm doing a reaction similar to that of Organic Syntheses, CV 4, 234
> > > (see: http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV4P0234

> > > In place of cyclohexanone, I'm using acetone so the desired product
> > > after the second step is methallyl cyanide (trivial name). The first
> > > step appears to go to completion since a full equivalent of water is
> > > collected in the Dean Stark trap. NMR tells me decarboxylation in the
> > > second step is incomplete and unreacted isopropylidenecyanoacetic acid
> > > (trivial name) is carried over with product even after two
> > > distillations. I'd like to improve on the published procedure (and
> > > avoid wasted product in a base wash). What would be some good ideas
> > > for promoting decarboxylation in the second step; added trace of H2SO4
> > > or Ag2O? Suggestions? Discussion? Thanks.





My suggestion would be DMAP (N,N-Dimethylaminopyridine) or chlorid
ions under nucleophilic conditions (e.g. sodium chloride in
dimethylformamide with heating).
-- 
Paul J. Franklin(moderator - sci.chem.organic.synthesis) 
http://organicworldwide.net/sci.chem.organic.synthesis
Georgia State University <[EMAIL PROTECTED]>
Atlanta, GA