The Structure of Acrylonitrile-Guanidine-Condensates. Heterocyclic Compounds. 81. Commun.

Article abstract of DOI:10.1007/BF00810006

Repetition of the work of Sugino and Tamaka showed that acrylonitrile and guanidine react in DMF to yield not only 3,4,6,7-tetrahydro-2H-pyrimido<1,2-a>pyrimidine-2,8(1H)-diimine (1), but a mixture (F) of 1 (as a main product) and 2-amino-4-imino-1,4,5,6-tetrahydropyrimidine-1-propionitrile (7) besides one or two bases not identified so far. 1 and 7 were isolated as picrates.For the prove of their structures, 1- and 7-picrate were also prepared by an unequivocal synthesis starting from iminodipropionitrile hydrochloride 8*HCl.The latter on reaction with cyanamide gave 9 which cyclized to afford a mixture of 1, 7 and 2-amino-4-oxo-1,4,5,6-tetrahydropyrimidine-1-propionitrile (10).The picrates of 1 and 7 were identical with those prepared from the acrylonitrile-guanidine condensate F.This result supports the prior proposed structures of pyrimidopyrimidine 1 and of 4, 5 and 6, obtained by hydrolysis of 1.Nmr-, ir- and some of the mass spectra of 1, 4, 7-10 (and their salts) are reported. - Keywords: Guanidine, N,N-bis(2-cyanoethyl), hydrochloride; 2H-Pyrimido<1,2-a>pyrimidin-2,8(1H)-diimine, 3,4,6,7-tetrahydro, picrate and sulfate; Pyrimidine-1-propionitrile, 1,4,5,6-tetrahydro-2-amino-4-imino and -4-oxo, picrates