3H-Pyrazol-3-one, 2,4-dihydro-2,5-dimethyl- → 4-isopropyl-6-methoxy-2-(1,3-dimethylpyrazol-5-yl-oxymethyl)-1,2-benzisothiazol-3(2H)-one 1,1-dioxide

Participants

Reaction Steps

To a solution of 2,4-dihydro-2,5-dimethyl-3H-pyrazol-3-one (475 mg; 4.24 mmol) in DMF (25 ml) was added 280 mg (4.83 mmol) of KF followed by 2-chloromethyl-4-isopropyl-6-methoxy-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (1 g, 3.3 mmol), and the resulting mixture was stirred at room temperature for 24 hours and then was poured into ice/water. The above mixture was extracted with ethyl acetate and the organic layer was washed with water, dried, and concentrated in vacuo. The residue was purified by flash chromatography to afford 0.46 g (37%) of 4-isopropyl-6-methoxy-2-(1,3-dimethylpyrazol-5-yl-oxymethyl)-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (Formula I: R1 =R2 =CH3 ; R3 =H; R4 =CH(CH3)2 ; R5 =6-OCH3) as a white solid, m.p. 146°-147° C.

Provenance & Evidence