There are disclosed novel intermediates useful in the preparation of pyrido[2,3-d]pyrimidines having the following structures: ##STR1## wherein R is CH.sub.3, CH.sub.3 CH.sub.2, CH.sub.3 CH.sub.2 CH.sub.2, CH.sub.2 .dbd.CHCH.sub.2 or CH.tbd.CCH.sub.2 ; and ##STR2## wherein R is CH.sub.3, CH.sub.3 CH.sub.2, CH.sub.3 CH.sub.2 CH.sub.2, CH.sub.2 .dbd.CHCH.sub.2 or CH.tbd.CCH.sub.2. These intermediates have the formulas: ##STR3## wherein Y is CHO, CH.sub.2 OH or CH.sub.2 Br; and Z is CH.sub.2 OH or CH.sub.2 Br.
揭示了一种在制备具有以下结构的
吡啶并[2,3-d]
嘧啶时有用的新型中间体:##STR1## 其中R为CH.sub.3,CH.sub.3 CH.sub.2,CH.sub.3 CH.sub.2 CH.sub.2,CH.sub.2 .dbd.CHCH.sub.2或CH.tbd.CCH.sub.2;以及##STR2## 其中R为CH.sub.3,CH.sub.3 CH.sub.2,CH.sub.3 CH.sub.2 CH.sub.2,CH.sub.2 .dbd.CHCH.sub.2或CH.tbd.CCH.sub.2。这些中间体的公式为:##STR3## 其中Y为CHO,CH.sub.2 OH或CH.sub.2 Br;Z为CH.sub.2 OH或CH.sub.2 Br。