Water → 1-[3-(4-(4-Fluorophenyl)piperazinyl)propyl]-5,6-dihydro(1H,4H)-1,2,5-thiadiazolo[4,3,2-ij]quinoline 2,2-dioxide

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Reaction Conditions

Reaction Steps

A solution of 5,6-dihydro(1H,4H)-1,2,5-thiadiazolo[4,3,2-ij]quinoline 2,2-dioxide (5.34 g) in dry N,N-dimethylformamide (50 cc) is added dropwise to a suspension of sodium hydride (0.72 g, 80% suspension in oil) in N,N-dimethylformamide (20 cc). After 15 minutes' stirring, 1-(3-chloropropyl)-4-(4-fluoro-phenyl)piperazine (7.68 g) is added. The reaction mixture is heated to 100° C. for 1 hour and 30 minutes and is then cooled and poured into a mixture of water (300 cc) and ethyl acetate (500 cm). The organic phase is washed with water (3×200 cc), is dried over magnesium sulphate and is concentrated to dryness under reduced pressure (2.7 kPa). The residue is chromatographed on a column of silica gel (0.2-0.063-mm particle size, 6-cm diameter, 50-cm height) and eluted at a pressure of 0.7 bars of nitrogen with a mixture of cyclohexane and ethyl acetate (80-20 by volume), 125-cc fractions being collected. Fractions 10 to 28 are combined and concentrated to dryness under reduced pressure (2.7 kPa). The solid obtained is recrystallized from ethanol (80 cc). 1-[3-(4-(4-Fluorophenyl)piperazinyl)propyl]-5,6-dihydro(1H,4H)-1,2,5-thiadiazolo[4,3,2-ij]quinoline 2,2-dioxide (7.2 g) is obtained, melting at 98° C.

Provenance & Evidence