Cesium → 4,6-diethoxy-2-[1-phenyl-3-trifluoromethylpyrazol-5-yl-oxymethyl]-1,2-benzisothiazol-3(2H)-one 1,1-dioxide

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Reaktionsschritte

The cesium salt of 1-phenyl-3-trifluoromethyl-5-hydroxypyrazole [prepared from 1-phenyl-3-trifluoromethyl-5-hydroxypyrazole (0.714 g, 0.312 mmol) and Cs2CO3 (0.509 g, 0.156 mmol)] was suspended in DMF (20 ml) and treated with 2-chloromethyl-4, 6-diethoxy-1,2-benzisothiazol-3 (2H)-one 1,1-dioxide (0.5 g, 0.156 mmol). The reaction mixture was stirred at room temperature for 24 hours, then was poured onto ice-water and was extracted with ethyl acetate (300 mL). The organic layer was washed with water, then brine and then was dried over MgSO4. The solvent was removed and the residue was purified by flash chromatography on silica gel eluting with CH2Cl2 to afford 0.57 g (71%) of 4,6-diethoxy-2-[1-phenyl-3-trifluoromethylpyrazol-5-yl-oxymethyl]-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (Formula I: R1 =Ph; R2 =CF3 ; R3 =H; R4 =OEt; R5 =6-OEt), m.p. 159°-160° C.

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