Methyl 4-chloro-6-oxo-1-[3-(trifluoromethyl)-phenyl]-1,6-dihydro-3-pyridazinecarboxylatemethyl 4-chloro-6-oxo-1-[3-(trifluoromethyl)phenyl]-1,6-dihydro-3-pyridazinecarboxylate3-[4-Chloro-3-(methoxycarbonyl)-6-oxopyridazin-1(6H)-yl]benzotrifluorideMethyl 4-chloro-1,6-dihydro-6-oxo-1-[3-(trifluoromethyl)phenyl]pyridazine-3-carboxylate4-Chloro-1,6-dihydro-3-(methoxycarbonyl)-6-oxo-1-[3-(trifluoromethyl)phenyl]pyridazine