The use of sustainable and efficient heterogeneous catalyst system TsOH‐SiO₂ shows unprecedented catalytic efficiency in the synthesis of biologically active 4H‐pyrido[1,2‐a]pyrimidin‐4‐one derivatives from 2‐aminopyridine and β‐oxo esters. The protocol provides advantages such as faster reactivity, high catalytic activities without any additives, high yields, no toxic/corrosive byproducts, broad substrate scope, reusability of the catalyst under solvent‐free conditions and scalable to gram scale, thus having economical and ecological advantages.

中文翻译：

---

多金属催化剂上无金属合成4H-吡啶并[1,2-a]嘧啶-4-酮衍生物的方法

使用持续高效多相催化剂体系加入TsOH-的SiO ₂中的生物活性4的合成示出了前所未有的催化效率ħ -吡啶并[1,2-一个]嘧啶-4-酮由2-氨基吡啶和β氧代酯衍生物。该协议具有以下优势：反应速度更快，没有任何添加剂的高催化活性，高收率，无毒/腐蚀性副产物，广泛的底物范围，催化剂在无溶剂条件下的可重复使用性以及可扩展至克级，因此具有经济和生态优势。