The Reactions of Guanidine and Urea with Cyanohydrines

Article abstract of DOI:10.1007/BF00899786

Action of guanidine or urea on cyclohexanone-, cyclopentanone-, cycloheptanone- and acetonecyanohydrine 3a-3d generates very different products: 3a reacts with guanidine in DMF to yield 1,3-diazaspiro<4.5>decane-2,4-diimine (5a).Heating the components without solvent affords 7,14-diazadispiro<5.1.5.2>pentadecan-15-one (7), the guanidine not participating in the reaction; similarly 3b is transformed by guanidine to a pentacyclic dispirocompound (possible formulae 19 and 20), whereas 3d reacts to give 3,3,5,5-tetramethylpiperazine-2,6-dion (21).In 3-pentanone guanidine- cyanide condensates itself to give 2,4-diamino-triazine (22).Action of urea on 3a-3d yields the 4-imino-1,3-diazaspiroalkan-2-ones 6a-6c and the 4-imino-5,5-dimethylimidazolidin-2-one 6d resp.If the reaction of urea and 3d is carried out in DMF, however, 5,5-dimethyl-4-ureido-3-imidazolin-2-one (28) (or the tautomeric carbamoyliminoimidazolidinone 27) is produced.The structures of the compounds prepared are proved by NMR-, IR- and mass spectra. - Keywords: 1.3-Diazaspiroalkan-2-ones. 4-imino; 1.3-Diazaspiro<4.5>decan-2.4-diimine; Guanidine-cyanide. reactions with ketones; Guanidine. reactions with cyanohydrines; 2-Imidazolines, 4-imino-5.5-disubstituted; Urea. reactions with cyanohydrines