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 (see Example 1I) for preparation), 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 with a water trap for 4 hours, during which a precipitate which originally separated out slowly dissolved. The toluene was then stripped off under reduced pressure, and the remaining residue was stirred with methyl tert-butyl ether and then filtered out. The resulting solid residue was dissolved in dichloromethane, and the solution was made alkaline by adding aqueous sodium carbonate solution while cooling in ice. The dichloromethane phase was then separated, washed with water, dried over sodium sulfate and evaporated. The resulting crude product was recrystallized from methyl tert-butyl ether for purification. 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 105° to 107° C.

Provenance & Evidence