Ethyl 7-oxo-3-(4-tolyl)-4,5,6,6a,7,8-hexahydro-3H-cyclopenta[b][1,2,4]triazolo[4,3-a][1,5]benzodiazepine-1-carboxylate and ethyl 3-(4-chlorophenyl)-8-methyl-7-oxo-4,5,6,6a,7,8-hexahydro-3H-cyclopenta[b][1,2,4]triazolo[4,3-a][1,5]benzodiazepine-1-carboxylate

The condensation reaction of 1,5-benzodiazepin-2-one with ethyl hydrazono-[alpha]-bromoglyoxylate in the presence of triethylamine is peri and regioselective, as indicated by the structures of the title cycloadducts. Moreover, these structures indicate that the dipole addition occurs in a unique way on the C=N double bond.

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