Water → N-[4-(1-(2-Methoxyphenyl)-4-piperazinyl)butyl]-1,2-benzisothiazole-3-carboxamide dihydrochloride

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Reaction Steps

A mixture of 1,2-benzisothiazole-3-carboxylic acid chloride (2.44 g), 1-(2-methoxyphenyl)-4-(4-aminobutyl)piperazine (3.26 g), and triethylamine (6 ml), in sieve-dried toluene (100 ml) was heated to 80° C., with stirring, overnight. After 24 hr, the reaction mixture was cooled to room temperature and poured into water. The organic phase was separated and the aqueous phase was extracted with ether. The ether extracts and toluene phase were combined, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated in vacuo. The residue was chromatographed on silica using ethyl acetate as the eluent. The appropriate fractions were collected and concentrated. The residue was taken up in ether and ethereal hydrogen chloride was added. The precipitate was recrystallized from ethanol/ethyl acetate and dried (0.1 mm mercury, refluxing toluene temperature) to provide 2.13 g (34.6%) of product, mp 174°-178° C.

Provenance & Evidence