Patent ID: 8110702

Claim:
A process for the manufacture of a compound of formula (I) wherein R 1 is hydrogen, C 1 -C 4 alkyl groups, C 1 -C 4 alkoxy group R 2 is hydrogen, C 1 -C 4 alkyl or phenyl and R 3 is a C 1 -C 12 alkyl, wherein the process comprises reacting a cyanoacetic ester of formula (II) with a carbonyl compound of formula (III) in a molar ratio of the cyanoacetic ester to the carbonyl compound in a range of about 0.7 to 0.8 and in the presence of: (i) an organic solvent, (ii) a C 3 -C 6 monocarboxylic acid, and (iii) an ammonium compound.