Abstract: 2,4-diamino-5-methyl-6-substituted-benzyl pyrido-(2,3d) pyrimidines are a kind of promising anticancer drugs. ¹³C NMR spectra of 24 kinds of 7-chloro and 7-oxo compounds have been studied in this paper. The chemical shifts of all carbons in the parent nuclei and subitituted benzyl have successfully been assigned. The influential factors on chemical shifts of all carbons in parent nuclei for two substituted groups have been approached in depth. To date, the data in this paper have not been published in the world.

Key words: ¹³C NMR, 2,4-diamino-5-methyl-6-substituted-benzyl pyrido-(2,3d) pyrimidines