A microwave-promoted multicomponent reaction of 3-formylchromones, amines, and paraformaldehyde was achieved under catalyst-free and solvent-free conditions, delivering 5H-chromeno[2,3-d]pyrimidin-5-one derivatives in good to excellent yields via an unexpected annulation pathway, which further expanded the synthetic application of paraformaldehyde as a C1 building block.

中文翻译：

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微波促进多组分反应合成5H-Chromeno[2,3-d]pyrimidin-5-one衍生物

在无催化剂和无溶剂条件下实现了 3-甲酰基色酮、胺和多聚甲醛的微波促进多组分反应，以良好至优异的产率提供 5 H-色烯[2,3 - d ]嘧啶-5-酮衍生物通过一个意想不到的环化途径，进一步扩大了多聚甲醛作为 C1 结构单元的合成应用。