5-甲基-4-氧代-3,4-二氢噻吩并[2,3-d]嘧啶-6-甲酸乙酯衍生物的合成

在吗啡啉催化下,利用Gewald反应使乙酰乙酸乙酯、氰基乙酸乙酯与硫反应得到中间体5-氨基-3-甲基噻吩-2,4-二甲酸乙酯(2),再与原甲酸三乙酯反应生成5-乙氧基亚甲胺-3-甲基噻吩-2,4-二甲酸乙酯(3),最后再与相应的伯胺反应生成了4个目标产物5-甲基-4-氧代-3,4-二氢噻吩并2,3-d]嘧啶-6-甲酸乙酯衍生物(4a~4d),所得产物结构经由1H NMR,IR,MS进行了确证.结果表明:该研究方法原料易得,反应条件适宜,所得化合物产量较高.

Synthesis of 5-Methyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrimidine-6-carboxylate Derivatives

5-amino-3-methylthiophene-2,4-dicarboxylate (2) was synthesized by ethyl acetoacetate, ethyl cyanoacetate and sulfur through Gewald reaction under the catalysis of morpholine. Then 5-(ethoxymethyleneamino)-3-methylthiophene-2,4-dicarboxylate (3) was synthesized by reacting 2 with triethyl orthoformate. Finally four derivatives (4a~4d) of 5-methyl-4-oxo-3,4-dihydrothieno 2,3-d]pyrimidine-6-carboxylate were obtained from the reaction of 3 with the corresponding amines. The structures were confirmed by 1H-NMR, IR and MS. The results showed that the raw materials were easily available and the target compounds could be obtained with mild reaction conditions and high yield.