中文摘要：

甲基脲和氰乙酸经缩合、环化制得3-甲基-4-氨基脲嘧啶（2）;2与亚硝酸盐经亲电加成制得3-甲基-4-氨基-5-亚硝基脲嘧啶（3）;3经加氢还原、酰化、闭环及酸化合成了3-甲基黄嘌呤（6a）及其衍生物（6b～6f,其中6c～6f为新化合物）,其结构经1H NMR和FT-IR表征。

英文摘要：

4-Amino-3-methyluracil（2） was prepared from methylurea with cyanoacetic acid by condensation and cyclization.4-Amion-3-methyl-5-nitrosouracil（3） was obtained by electrophilic addition of 2 with nitrite.3-Methylxanthine（6a） and its derivatives（6b～6f,6c～6f were new compounds） were synthesized from 3 by hydrogenation,acylation,cyclization and acidification.The structures were characterized by 1H NMR and FT-IR.