Potassium Fluoride → 4-isopropyl-6-methoxy-2-[1-(4-pyridyl)-3-trifluoromethylpyrazol-5-yl-oxymethyl]-1,2-benzisothiazol-3(2H)-one 1,1-dioxide

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Reaction Steps

To a mixture of 1-(4-pyridyl)-3-trifluoromethyl-5-hydroxypyrazole (316 mg; 1.36 mmol) in DMF (20 ml) was added 128 mg (2.24 mmol) of KF at room temperature under nitrogen, and the mixture was stirred for 20 minutes. To the above solution was added 2-bromomethyl-4-isopropyl-6-methoxy-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (400 mg, 1.12 mmol) and the resulting mixture was stirred at room temperature for 45 minutes. The above mixture was quenched with ice/saturated ammonium chloride, extracted with ether (3×) and the organic layer was washed with water, dried over magnesium sulfate, and concentrated in vacuo. The residual yellow solid was purified by column chromatography (silica gel; 30-50% ethyl acetate in hexane) to afford 240 mg (43%) of 4-isopropyl-6-methoxy-2-[1-(4-pyridyl)-3-trifluoromethylpyrazol-5-yl-oxymethyl]-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (Formula I: R1 =4-pyridyl; R2 =CF3 ; R3 =H; R4 =CH(CH3)2 ; R5 =6-OCH3) as a white solid, m.p. 161°-162° C.

Provenance & Evidence