An efficient, solvent-free and one-pot procedure for the synthesis of pyrido[2,3-d]pyrimidine derivatives by condensation of aromatic aldehydes, malononitrile and 6-amino-1,3-dimethyl uracil at 90°C catalyzed by lactic acid as an inexpensive, biological and eco-friendly compound is described. The remarkable benefits of this procedure are green and environmentally friendly reaction conditions, high yields, short reaction time, simple methodology and easy workup.

中文翻译：

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以乳酸为绿色环保催化剂高效无溶剂合成吡啶并[2,3-d]嘧啶衍生物

一种高效、无溶剂、一锅法合成吡啶并[2,3-d]嘧啶衍生物的方法，通过乳酸催化芳香醛、丙二腈和6-氨基-1,3-二甲基尿嘧啶在90°C的缩合反应酸作为一种廉价、生物和环境友好的化合物被描述。该方法的显着优点是反应条件绿色环保、收率高、反应时间短、方法简单、后处理容易。