Journal of Heterocyclic Chemistry, vol. 23, Sep.-Oct. 1986, pp. 1443-1449, K. Takagi, et al., "Synthesis of Pyrimidino[4,5-b][1,5]Benzodiazepin-2-Ones And Pyrimidino[1,6-a]Benzimidazol-1-Ones From 4-Ethoxycarbonylamino-1H-1,5-Benzodiazpine-3-Carbonitrile . . . ". |
Journal of Heterocyclic Chemistry, vol. 28, No. 2, Feb.-Mar. 1991, pp. 485-487, T. Aotsuka, et al., "Ring Transformation Of 4-Amino-1H-1,5-Benzodiazepine-3-Carbonitrile And Ethyl 4-Amino-1H-1,5-Benzodiazepine-3-Carboxylate Into Benzimidazole . . . ". |