3-(1-Piperazinyl)-1,2-benzisothiazole → 1-[4-[4-[4-(1,2-Benzisothiazol-3-yl)-1-piperazinyl]butoxy]3-methoxyphenyl]ethanone

Participants

Reaction Steps

A mixture of 3-(1-piperazinyl)-1,2-benzisothiazole (4.0 g, 18.2 mmol), 1-[4-(4-bromobutoxy)-3-methoxyphenyl]ethanone (6.0 g, 20.0 mmol), K2 CO3 (3.0 g, 21.8 mmol), KI (200 mg), and acetonitrile (125 ml) was stirred at reflux under N2 for 5 hours. Most of the solvent was removed in vacuo and the resultant gummy residue was partitioned between ethyl acetate and water. The organic extract was washed with water, dried with MgSO4, and concentrated to yield 7.8 g. Purification by preparative HPLC (Waters Associates Prep LC/System 500, utilizing 2 silica gel columns and 4% methanol-methylene chloride as eluent) afforded 6.5 g of a damp, off-white solid. The product was recrystallized twice from toluene to provide 3.1 g (39%) of 1-[4-[4-[4-(1,2-benzisothiazol-3yl)-1-piperazinyl]butoxy]-3-methoxyphenyl]ethanone as a white solid, m.p.=114°-116° C.

Provenance & Evidence