N,N-coupled heterobicycles from cyclic hydrazine derivatives. Part 7. Investigations on the synthesis and structure of 1-(N1,N2-alkanediylcarbamimidoyl)pyrazolidine derivatives

Abstract

1-(N¹, N²-Alkanediylcarbamimidoyl) pyrazolidines (containing either a dihydroimidazole or tetrahydrodiazepine ring unit) have been prepared in the form of crystalline iodine complexes from, pyrazolidine and cyclic N,N′-alkanediyl-S-methylisothiouronium salts, and the structures were investigated by NMR spectroscopy, mass spectrometry and X-ray crystallography. The compounds exhibited resonance behaviour typical of monoprotonated aminoguanidine derivatives. In consequence of the resonance in the guanidine moiety, a planar area including members of both heterocyclic ring systems was formed in the molecule.