Patent ID: 6930197

Claim:
A process for preparing a compound of the formula: wherein R 1 is C 1 -C 6 alkyl and the C 1 -C 6 alkyl moiety is straight or branched: comprising the steps of: a) reacting a benzene acetic acid ester of the formula: wherein R 1 is C 1 -C 6 alkyl and the C 1 -C 6 alkyl moiety is straight or branched; with a 4-halo-substituted butyrylhalide under Friedel-Crafts conditions to provide a mixture of para and meta substituted ω-halo-α-keto-benzeneacetic acid ester of the formula: wherein R 1 is as previously defined herein and X is Cl, Br, or I; (b) hydrolyzing the mixture of para and meta substituted (ω-halo-α-keto substituted benzene acetic acid ester to provide a mixture of para and meta substituted (cyclopropylcarbonyl)benzene acetic acid ester of the formula: (c) selectively crystallizing and isolating the substantially pure 4-(cyclopropylcarbonyl)benzene acetic acid.