Synthesis of isomelamines and isocyanurates and their biological evaluation

The reaction of cyanogen bromide (1) with primary amines (2a-p), including arylmethylamines (2l-p), gave the corresponding cyanamides (3a-p). Trimerization of 3a-p gave 1,3,5-trisubstituted 2,4,6-triiminohexahydro-1,3,5-triazines (isomelamines) (4a-p), which were treated with hydrochloric acid to give the corresponding 1,3,5-trisubstituted 2,4,6-trioxohexahydro-1,3,5-triazines (isocyanurates) (5a-c, f) and 1,3,5-trisubstituted 2-imino-4,6-dioxohexahydro-1,3,5-triazines (5b'-e'). Biological evaluation of 4a-p, 5a-c,f, and 5b'-e' was carried out, and some of these compounds showed bronchodilator and positive inotropic activities.