9, 9-Dialkyloctahydropyrimido [3, 4-a]-s-triazines were synthesized by iminodimethylation reaction between a 5, 5-dialkyl-6-aminopyrimidine-2, 4 (3H, 5H)-dione, a substituted aniline and two moles of formaldehyde. The synthesis of 5, 5-dialkyl-6-aminopyrimidinedione consisted of the condensation of urea with ethyl 2, 2-dialkylcyanoacetates. 18 Octahydropyrimido [3, 4-a]-s-triazines were synthesized and compounds resulting from a ...