Hydrochloric Acid → 1-(3-Aminopropyl)-4-(6-fluoro-1,2-benzisoxazol-3-yl)piperidine dihydrochloride

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Reaction Steps

A mixture of N-[3-[4-(6-fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl]-propyl]phthalimide (8.5 g, 21 mmol), hydrazine monohydrate (1.5 g, 30 mmol) in methanol (60 ml) was heated at reflux for hours. At the end of the reaction, methanol was removed to leave a crude solid. To this was added water (60 ml), then the mixture was acidified with HCl to pH 1. The insolubles were filtered with the aid of a pad of Celite. The aqueous solution was basified with 50% NaOH, (pH 13), then extracted with dichloromethane. The combined dichloromethane solution was washed with brine, then dried to a colorless oil (4.5 g). The analytical sample (1.5 g) was prepared by treating the oil with HCl in ethanol at 0° C. The 1-(3-aminopropyl)-4-(6-fluoro-1,2-benzisoxazol-3-yl)piperidine dihydrochloride was obtained as white crystals, 2.03 g, m.p.=231°-234° C.

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