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 2 hours. At the end of the reaction, methanol was removed to leave a crude solid. To this was added water (60 mi), 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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