Sodium hydride → 2-{3-[4-(4-Fluorophenyl)-1-piperazinyl]butyl}naphtho[1,8-cd]isothiazole 1,1-dioxide

Participants

Reaction Conditions

Reaction Steps

A solution of naphtho[1,8-cd]isothiazole 1,1-dioxide (3.25 g) in dimethylformamide (50 cc) is poured over 30 minutes into a mixture of sodium hydride (0.76 g) in a 50% dispersion in vaseline oil and dimethylformamide (10 cc), under a current of argon. The reaction medium is stirred for 2 hours at a temperature of about 20° C. 1-(4-bromo-2-butyl)-4-(4-fluorophenyl)piperazine (5 g) in dimethylformamide (100 cc) is added over 10 minutes. The reaction mixture is stirred for 15 hours at a temperature close to 20° C., then concentrated to dryness at 40° C. under reduced pressure (20 mm Hg; 2.7 kPa). The residual oil is purified by flash-chromatography on silica column, under a current of argon at medium pressure (0.5-1.5 bar) with a mixture of dichloromethane and ethyl acetate (80-20 vol) as eluant. After recrystallization from boiling acetonitrile (13 cc), 2-{3-[4-(4-fluorophenyl)-1-piperazinyl]butyl}naphtho[1,8-cd]isothiazole 1,1-dioxide (1.8 g) is obtained, m.p. 122° C.

Provenance & Evidence