process for the production of enollakton 2 oxycyclohexyliden acetic acid and used for production of 2 - coumaranon

摘要

Preparation of 2-oxo cyclohexylidene acetic acid enol-lactone (I) comprises: (i) reacting glyoxylic acid with cyclohexanone in the presence of a halogenated acid to give a crude reaction product; and (ii) dissolving the above product in an organic solvent in the presence of a strong soluble acid or a strongly acidic resin. In (i), the acid is preferably HCl added in a 1-100% molar amount w.r.t. glyoxylic acid and the reagents are heated above 50 degrees C. The resulting crude product is dissolved in a solvent containing a benzene ring and treated with methane sulphonic acid or p-toluene sulphonic acid or with a strongly acidic sulphonic Amberlist (RTM) resin.