Patent ID: 7012145

Claim:
A method of making 4-(3-cyanophenyl)-5-oxo-2-(trifluoromethyl)-1,4,5,6,7,8-hexahydroquinoline-3-carboxylic acid, comprising: a) reacting an ester of 4,4,4-trifluoro-3-oxobutanoate with 1,3-cyclohexanedione and 3-cyanobenzaldehyde to form an ester of 4-(3-cyanophenyl)-2-hydroxy-5-oxo-2-(trifluoromethyl)1,2,3,4,5,6,7,8-octahydroquinoline-3-carboxylate; b) dehydrating said ester of 4-(3-cyanophenyl)-2-hydroxy-5-oxo-2-(trifluoromethyl)-1,2,3,4,5,6,7,8-octahydroquinoline-3-carboxylate to form an ester of 4-(3-cyanophenyl)-5-oxo-2-(trifluoromethyl)-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate, and c) de-esterifying said ester of 4-(3-cyanophenyl)-5-oxo-2-(trifluoromethyl)-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate to form 4-(3-cyanophenyl)-5-oxo-2-(trifluoromethyl)-1,4,5,6,7,8-hexahydroquinoline-3-carboxylic acid.