An efficient one-pot synthesis of novel 4H,5H-pyrano[2,3-d]pyrido [1,2-a]pyrimidin-5-one derivatives has been developed. This method involves the three-component condensation of 2‑hydroxy-4H-pyrido[1,2-a]pyrimidin-4-one, aromatic aldehydes and (E)-N-methyl-1-(methylthio)-2-nitroethenamine at 120 °C under neat reaction conditions in Monowave 50 reactor. A simple procedure, catalyst free, short reaction time, high yields and non‐column chromatographic separation are attractive features of this process.

中文翻译：

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新型4H,5H-吡喃并[2,3-d]吡啶并[1,2-a]嘧啶-5-one衍生物的无催化剂一锅法合成

已开发出一种新型 4 H ,5 H -pyrano[2,3- d ] pyrido [1,2 - a ]pyrimidin-5-one 衍生物的高效一锅法合成方法。该方法涉及 2-羟基-4 H-吡啶并[1,2 - a ]嘧啶-4-酮、芳香醛和 ( E ) -N-甲基-1-(甲硫基)-2-硝基乙胺的三组分缩合在 Monowave 50 反应器中，在 120 °C 的纯反应条件下。该工艺具有程序简单、无催化剂、反应时间短、收率高和非柱色谱分离等特点。