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

Abstract

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 NaBH 3CN or boran-triethylamine complex directly gave 2 in good yield without racemization.