To 25.5 g (50.8 mmole) of N-(4-trifluoromethoxyphenyl)-3-(4-difluoromethoxyphenyl)-4-(N-methyl-N-(methoxycarbonyl)amino)-4,5-dihydro-1H-pyrazole-1-carboxamide dissolved in 25 g of tetrahydrofuran and 25 g of t-butanol was added 10 g of potassium t-butoxide. The mixture was refluxed for 1 hour and an additional 3.5 g of potassium t-butoxide was added. After refluxing an additional hour the mixture was acidified with acetic acid, concentrated in vacuo, and partitioned between methylene chloride and water. The organic layer was dried over anhydrous magnesium sulfate, filtered, concentrated in vacuo, and chromatographed over silica gel using hexane and diethyl ether to yield the expected compound, a white solid, mp 228°-233° C.
