A catalyst-free and solvent-free synthetic route for convenient one-pot synthesizing pyrano[2,3-d] pyrimidine scaffolds through Knoevenagel-Michael cyclocondensation is reported using visible light irradiation as a green promoter at room temperature based on green chemistry principles. Completing the reactions takes thoroughly less time while obtaining the products in outstanding yields. This green method includes the application of non-hazardous reaction circumstances, direct work-up without column chromatographic separation, catalyst-free, solvent-free, cost effective, simple synthesis, one-pot procedure, and high atom-economy.

中文翻译：

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可见光辐射促进室温下无催化剂和无溶剂合成吡喃并[2,3- d ]嘧啶骨架

据报道，基于绿色化学原理，在室温下使用可见光作为绿色助催化剂，通过Knoevenagel-Michael环缩合反应方便地一锅合成吡喃并[2,3- d ]嘧啶骨架的无催化剂和无溶剂合成路线。完成反应所需的时间大大减少，同时获得了优异的收率。这种绿色方法包括在无危险的反应情况下应用，无需柱色谱分离即可直接进行后处理，无催化剂，无溶剂，经济高效，合成简单，一锅法和高原子经济性。