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 benzylpyrimidine 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;R.sup.5是烷基;烷基或烷
氧基中的每个都有1至4个
碳原子,它们用作制备抗菌
2,4-二
氨基-5-
苄基嘧啶的
中间体。它们是由正
酯和α-取代的β-
苄基丙腈的反应制备而成,然后将得到的
氰酸酯与
胍反应转化为
苄基嘧啶。