2, 4-Diamino-6-phenethylpyrimidines (11) were formed by condensation of 5-aryl-3- ketovalerates with guanidine carbonate to afford 2-amino-4-hydroxy-6- phenethylpyrimidine~, which were chlorinated and aminated. 2, 4-Diamino-6- phenethyltriazines (111) formed on condensation of biguanide with hydrocinnamates. Ring- halogenated hydrocinnamic acids were common intermediates to I1 and 111. 2, 4- ...