1978 Volume 26 Issue 12 Pages 3666-3674
Synthesis of acyl and alkyl derivatives of 1-benzyl or 1-benzhydryl-2-imino-1, 3-diazacycloalkanes (1) was attempted. Acetylation of 1a, c having five-membered ring with ethyl acetate gave 2-acetyl derivatives. However, reactions of 1a, c with dialkylcarbonate, acyl chloride and alkyl or aryl isocyanate afforded a mixture of 2- and 3-substituted compounds and reactions of 1a, c with isothiocyanate derivatives gave predominantly 3-substituted compounds. On the other hand, 1b, d having six-membered ring gave predominantly 2-substituted compounds by the similar reactions. Direct alkylation of 1a, c with alkyl iodide in the presence of sodium hydride yielded 3-alkyl derivatives (5). In the similar alkylations, 2-alkoxycarbonylimino and 2-cyanoimino derivatives, 2 and 9, gave 3-alkyl compounds 7 and 8, in which 2-alkaxycarbonyl and 2-cyano groups were removed on heating in t-butanol containing a small amount of hydrochloric acid to give 5 in good yields. Heating 7 and 8 having 1-benzhydryl group with sodium hydride gave 2-oxo- or 2-imino-3, 3-diphenylimidazo [1, 2-a] [1, 3] diazacycloalkane derivatives (10, 11 and 12). Some of 1-substituted 3-acyl and 3-alkyl-2-imino-1, 3-diazacycloalkanes showed hypoglycemic activity.