Water → 4-isopropyl-6-methoxy-2-[1-(4-nitrophenyl)-3-trifluoromethylpyrazol-5-yl-oxymethyl)-1,2-benzisothiazol-3(2H)-one 1,1-dioxide

Participants

Reaction Conditions

Reaction Steps

A mixture of 1-(4-nitrophenyl)-3-trifluoromethyl-5-hydroxypyrazole (450 mg; 1.65 mmol) and Cs2CO3 (269 mg; 0.825 mmol) in methanol (9 ml) was stirred at 20° C. for 4 hours. The solvent was concentrated in vacuo, and the residue was dried in vacuo overnight. To a solution of the above residue in 7 ml of DMF was added 2-bromomethyl-4-isopropyl-6-methoxy-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (479 mg, 1.37 mmol) and the resulting mixture was stirred at room temperature (20° C.) for 3 hours and then poured into water. The above mixture was extracted with ether (3×) and the organic layer was dried over sodium sulfate, and concentrated in vacuo. The residue was purified by column chromatography (silica gel; 18-33% ethyl acetate in hexane) and recrystallized from methylene chloride/hexane to afford 350 mg (47%) of 4-isopropyl-6-methoxy-2-[1-(4-nitrophenyl)-3-trifluoromethylpyrazol-5-yl-oxymethyl)-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (Formula I: R1 =4-NO2 --Ph; R2 =CF3 ; R3 =H; R4 =CH(CH3)2 ; R5 =6-OCH3) as a white solid, m.p. 185°-187° C.

Provenance & Evidence