Triphenylphosphine → 4-isopropyl-6-[3-methyl-3-(phenylmethyloxycarbonyl)butoxy]-2-(1-phenyl-3-trifluoromethylpyrazol-5-yl-oxymethyl)-1,2-benzisothiazol-3 (2H)-one 1,1-dioxide

Participants

Reaction Steps

A mixture of 4-isopropyl-6-hydroxy-2-(1-phenyl-3-trifluoromethylpyrazol-5-yl-oxymethyl)-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (7 g; 14.55 mmol), 4-hydroxy-2,2-dimethylbutyric acid phenylmethyl ester (3.88 g;17.46 mmol), DEAD (3.04 g; 17.46 mmol) was dissolved in 180 ml of THF at 00C and then (Ph)3P (4.575 g; 17.46 mmol) was added at 0° C. The above mixture was stirred overnight at room temperature and concentrated in vacuo, and the residue was purified by column chromatography (2×, silica gel; 12-33% ethyl acetate/hexane;methylene chloride/hexane, 1/4-30/1) to afford 3.65 g (37%) of 4-isopropyl-6-[3-methyl-3-(phenylmethyloxycarbonyl)butoxy]-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 =CH(CH3)2 ; R5 =6-O(CH2)2 C(CH3)2CO2Ph) as a solid.

Provenance & Evidence