Summary 1. Although 2-nitramino-A2-1, 3-diazacyclopentene,-cyclohexene and- cycloheptene can be converted to the corresponding 1, 3-dinitro-1, 3-diazacyclopentanone- 2,-cyclohexanone-2 and-cycloheptanone-2, only the first of the nitramines gave a cyclic N, N1-dinitroguanidine. This nitration is unique among disubstituted acylic or cyclic guanidines, and may be owing to the enforced planarity of the diazacyclopentene ring.
