11/22/11 - Conversion of an Ester to an Acyl Chloride

   This here is a pretty complexed reaction to perform something simple that can be done in two steps.  But this technology saves much time and money in not having to do two steps and to separate and purify after those steps.  This involves taking the ester, and treating it with chlorosulfonic acid and phthalyl chloride while heating it in a mixture.  This reaction is limited to esters that can withstand these treatment conditions in the heat, so before the reaction the esters must be confirmed to not decompose in  these conditions.

Ref + Photo:
W.J. Middleton. J.  Org. Chem., Vol. 44,  No. 13, 1979