Sodium hydride → N,N-dimethyl-2-chloro-5-[3,6-dihydro-4-trifluoromethyl-2,6-dioxo-1(2H)-pyrimidinyl]-benzenesulfonamide

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Reaction Conditions

Reaction Steps

To 30 ml of dried tetrahydrofuran (THF) cooled to -5° C. was added, under nitrogen, 3.6 g of sodium hydride as a 60% dispersion mineral oil. To the stirred slurry was added a solution of 10 g of ethyl 3-amino-4,4,4-trifluoro-2-butenoate in 30 ml of THF over a period of 30 minutes. After stirring at -5° C. for 1 hour, the reaction mixture was cooled to -65° C. and a solution of N, N-dimethyl-2-chloro-5-isocyanatobenzenesulfonamide (Example A-4 above) in 30 ml of THF was added dropwise maintaining the temperature below -60° C. The mixture was stirred at -65° C. for 2 hours and allowed to warm to room temperature. After stirring for 17 hours, solvent was removed using a rotary evaporator. About 50 ml of water was added to the residue. The resulting mixture was filtered to remove a small amount of undissolved solid and the filtrate was acidified with hydrochloric acid. The resulting precipitate was filtered to give 13 g of the title compound as a beige solid, m.p. 281°-283° C.

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