Benzyl cyanoacetals of formula: ##STR1## wherein R.sup.1, R.sup.2 and R.sup.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.sup.4 is an alkoxycarbonyl group, or an aldehyde group; And R.sup.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 .alpha.-substituted-.beta.-benzylpropionitrile and then the resulting cyanoacetal is converted to the benzyl-pyrimidine by reaction with guanidine.
公式为:##STR1## 其中R.sup.1、R.sup.2和R.sup.3相同或不同,每个都是卤素或氢原子、烷氧基、烷基或二烷基
氨基;R.sup.4是烷氧羰基基团或醛基;而R.sup.5是烷基;烷基或烷氧基每个具有1至4个碳原子,并且它们作为中间体在制备抗菌2,4-二
氨基-5-苄基
嘧啶时使用。它们是通过正交酯和α-取代-β-苄基
丙腈之间的反应制备的,然后将得到的
氰酸酯与
胍反应转化为苄基
嘧啶。