Azepinones: IV. A synthetic route to some Dihydro- and Tetrahydro-1, 3-diazepines

Lh-4, 5, 6, 7-Tetrahydro-2-methyl-1, 3-diazepine (1), 4H-1, 5-dihydro-3-methyl-benzo[e]-[1, 3]-diazepine (11), and 3H-4, 5-dihydro-2-methylbenzo[d]-[1, 3]-diazepine (IV) have been synthesized in good yields by treating suitably substituted 1, 4-diaminobutanes with acetamidine hydrochloride under mild experimental conditions. This synthetic method may well be a general one for such compounds. When protonated, the compounds exist as amidinium salts, and the free bases (1) and (11) have basicities comparable to the 1, 4, 5, 6,-tetrahydropyrimidines. I.r., N.M.R., and mass spectra data are reported for (1), (11), and (IV)