Benzyl Alcohol → 1-benzyloxycarbonylmethyl-3-amino-2,3,4,5-tetrahydro-1H-[1]benzazepin-2-one

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Reaction Steps

10.5 g of tert-butyl 3-amino-2,3,4,5-tetrahydro-2-oxo-1H-1-benzazepine-1-acetate (preparation, see Example 3I), 8.25 g of p-toluenesulfonic acid hydrate and 20.1 ml of benzyl alcohol were added to 174 ml of toluene. The reaction mixture was boiled for 4 hours on a water separator, during which period a precipitate which had originally separated out went slowly in solution. After that, the toluene was swept off under reduced pressure and the remaining residue was stirred with methyl tert-butyl ether and then filtered off. The solid residue which was obtained in this way was dissolved in dichloromethane and the solution was rendered alkaline by adding aqueous sodium carbonate solution while cooling with ice. After that, the dichloromethane phase was separated, washed with water, dried over sodium sulfate and evaporated. The resulting crude product was recrystallized, for purification, from methyl tert-butyl ether. 8.2 g of benzyl 3-amino-2,3,4,5-tetrahydro-2-oxo-1H-1-benzazepine-1-acetate were obtained with a melting point of from 105° to 107° C.

Provenance & Evidence