| 摘要 |
Pyrimidines and purines are made according to the following reaction scheme, in which the last two stages are optional. <FORM:1089482/C2/1> The benzene ring contains 0-3 substituents (R1) which are C1- 4 alkyl, C1- 4 alkoxy, OH, halogen, NO2, SO3H or CO2H, and instead of the cyanoacetamide there may be used the corresponding cyanohydrazide, -hydroxylamide, -C1- 4-alkylamide, -carboxylic acid or its C1- 4 alkyl ester. The formamidine (which may be in the form of an acid addition salt) may be C-substituted by OH, SH, NH2, C1- 4-alkyl, -alkoxy or alkylmercapto, aryl, C1- 4-alkyl- or -alkoxy-phenyl, aryl-C1- 4-alkyl, or 2-pyridyl. In examples, the end-products ore hypoxanthine (and its 2-Me, 2-SH and 2-SMe derivatives), guanine and xanthine. |
