To 6.5 g of triphenyl phosphine and 2.5 g of potassium t-butoxide dissolved in 75 ml of THF and cooled to -70° C. was added 3.5 g of chloroform. After stiring for 5 minutes a solution of 3.9 g of N-(4-trifluoromethoxyphenyl)-3-(4-chlorophenyl)-4-formyl-4-methyl-4,5-dihydro-1H-pyrazole-1-carboxamide in 10 ml of THF is added and the mixture is allowed to warm to 10° C. over 1 hour. The resulting mixture is partitioned between ether and water, dried, rotovaped and chromatographed (ether/hexane) on silica gel yielding 3.1 g of N-(4-trifluoromethoxyphenyl)-3-(4-chlorophenyl)-4-(2,2-dichlorovinyl)-4-methyl-4,5-dihydro-1H-pyrazole-1-carboxamide mp 138°-141° C. NMR and IR data were consistent with the structure.
