benzyl 3(S)-tert-butoxycarbonylamino-4-oxo-2,3,4,5-tetrahydro-1,5-benzoxazepine-5-acetate → benzyl 3(S)-amino-4-oxo-2,3,4,5-tetrahydro-1,5-benzoxazepine-5-acetate hydrochloride

Participants

Reaction Steps

To 7.6 g of benzyl 3(S)-tert-butoxycarbonylamino-4-oxo-2,3,4,5-tetrahydro-1,5-benzoxazepine-5-acetate is added 30 ml of hydrogen chloride-ethyl acetate solution (5N) and the mixture stands for 3 hours at room temperature. The mixture is concentrated under reduced pressure and the resulting residue is crystallized from a mixture of ethyl acetate and ether to give 6.2 g of benzyl 3(S)-amino-4-oxo-2,3,4,5-tetrahydro-1,5-benzoxazepine-5-acetate hydrochloride as a colorless crystalline powder, melting at 169°-172° C.

Provenance & Evidence