Hydrochloric Acid → 3-(2-piperidinopropyl)-4-(3-methoxyphenyl)-1,5,6,7-tetrahydro-2H-azepinone

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Reaction Steps

The solution of 8.0 g of 3-acetonyl-4-(3-methoxyphenyl)-1,5,6,7-tetrahydro-2H-azepinone, 14.95 g of piperidine, 6.6 ml of 5 N methanolic hydrogen chloride and 1.9 g of sodium cyanoborohydride in 120 ml of methanol is refluxed overnight. An additional portion of 0.95 g of sodium cyanoborohydride is added and refluxing continued for 24 hours. The mixture is cooled to 0°, 30 ml of concentrated hydrochloric acid are added and the solution concentrated. The concentrate is diluted with 100 ml of water, the solution washed with benzene and rendered basic with 70 ml of 3 N aqueous sodium hydroxide. It is extracted with diethyl ether, the extract evaporated and the residue crystallized from petroleum ether and hexane, to yield the 3-(2-piperidinopropyl)-4-(3-methoxyphenyl)-1,5,6,7-tetrahydro-2H-azepinone of the formula ##STR7## melting at 97° to 99°.

Provenance & Evidence