| abstract |
Benzyl cyanoacetals of formula: ##STR1## wherein R 1 , R 2 and R 3 are the same or different and each is a halogen or a hydrogen atom, an alkoxy group, an alkyl group, or a dialkylamino group; R 4 is an alkoxycarbonyl group, or an aldehyde group; n And R 5 is an alkyl group; the alkyl or alkoxy groups each having from 1 to 4 carbon atoms, and their use as intermediates in the preparation of antibacterial 2,4-diamino-5-benzylpyrimidines. They are prepared from a reaction between an orthoester and an α-substituted-β-benzylpropionitrile and then the resulting cyanoacetal is converted to the benzyl-pyrimidine by reaction with guanidine. |