Efficient synthesis of (R)-6-benzyloxycarbonylamino-1-methyl-4-(3- methyl-benzyl)hexahydro-1,4-diazepine. 2. Novel formation of hexahydro-1,4- diazepine ring using 1,2,3-trisubstituted aminopropane derivative and glyoxal

Article abstract of DOI:10.1016/S0040-4020(98)00616-4

An efficient and practical method for synthesis of the optically active hexahydro- 1,4-diazepine 2, which is a key intermediate of DAT-582, a potent and selective serotonin-3 receptor antagonist, is described. Treatment of the (R)-1,2,3-trisubstituted aminopropane dihydrochloride 5b prepared from methyl (S)-1-tritylaziridine-2-carboxylate (4) via the (S)-1- benzyloxycarbonylaziridine-2-carboxamide 8 with glyoxal in the presence of NaBH₃CN or boran-triethylamine complex directly gave 2 in good yield without racemization.