Novel pyrazolo [4,3-e] [1,4] diazepin-5,8-diones

The synthesis of some pyrazolo [4,3-e] [1,4] diazepin-5,8-diones has been accomplished starting from the readily available 1-ethyl-3-methyl-4-nitro-5-pyrazolecarbonylchloride and the appropriate alpha-aminoesthers, 2a, b, c. The catalytic reduction of the obtained 3a, b, c gave the products 4a, b, c which were, in turn, cyclized into the title compounds 5a, b, c. The intermediates of type 3 and 4 and the pyrazolo-diazepin-diones 5 were tested in vitro for their antimicrobial activity.