Methyl 5-chloro-6-oxo-1-[4-(trifluoromethyl)-benzyl]-1,6-dihydro-3-pyridinecarboxylatemethyl 5-chloro-6-oxo-1-[4-(trifluoromethyl)benzyl]-1,6-dihydro-3-pyridinecarboxylateMethyl 5-chloro-1,6-dihydro-6-oxo-1-[4-(trifluoromethyl)benzyl]pyridine-3-carboxylate