Sulfuric Acid → 4-isopropyl-6-[3-(carboxy)propoxy]-2-[1-(4-chlorophenyl)-3-trifluoromethylpyrazol-5-yl-oxymethyl]-1,2-benzisothiazol-3(2H)-one 1,1-dioxide

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-isopropyl-6-[3-(phenylmethyloxycarbonyl)propoxy]-2-[1-(4-chlorophenyl)-3-trifluoromethylpyrazol-5-yl-oxymethyl]-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (4.19 g; 6.055 mmol) and 50 ml of 20% sulfuric acid in 80 ml of dioxane was heated at 100° C. for 20 hours. The mixture was cooled, poured into ice, neutralized with sodium bicarbonate solution (160 ml, to pH=5), and the resulting solid was filtered and recrystallized (3×, ethyl acetate/hexane; methylene chloride/hexane; and acetonitrile) to afford 2.56 g of 4-isopropyl-6-[3-(carboxy)propoxy]-2-[1-(4-chlorophenyl)-3-trifluoromethylpyrazol-5-yl-oxymethyl]-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (Formula I: R1 =4-Cl--Ph; R2 =CF3 ; R3 =H; R4 =CH(CH3)2 ; R5 =6-O(CH2)3CO2H) as a white solid, 162°-164° C.

Provenance & Evidence