| abstract |
A process for preparing a compound of the formula <IMAGE> I wherein R1 and R2 are lower alkoxy or taken together are methylenedioxy; R3 is lower alkyl or hydrogen, which comprises the step of reacting an aromatic compound of the formula <IMAGE> wherein R1, R2 and R3 are as previously described, with a diamino-pyrimidine of the formula <IMAGE> wherein R4 is lower alkoxy, benzyloxy, hydroxy or halogen, in the presence of an inorganic or organic acid selected from the group consisting of ortho-phosphoric acid, poly-phosphoric acid, hydrohalic acids and tri-haloacetic acids, at a temperature in the range of from about 50 DEG C. to about 110 DEG C., is described. |