Aim and Objective: In the last decades, it has extensively been verified that nanostructured transition metal oxides emerge as inexpensive, available and extremely efficient heterogeneous catalysts in chemical transformations. The high electrical conductivity, high carrier concentration, and improved reactivity in cadmium oxide nanoparticles (CdO NPs) make it as a potential candidate for applications in the fields of nanocatalysis. [1]Benzopyran and pyridopyrimidine derivatives compose major classes of heterocyclic compounds, which have a wide spectrum of biological activities.

Materials and Methods: In the present work, we report a facile and highly effective synthesis of 8- aryl-8H-[1,3]dioxolo[4,5-g][1]benzopyran-6-carboxylic acids and 1,3-dimethyl-2,4-dioxo-5- phenyl-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine-7-carboxylic acids via CdO NPs catalyzed cyclo condensation reaction of 4-substituted phenylmethylidenepyruvic acids with 3,4- methylenedioxyphenol or 6-amino-1,3-dimethyluracil, which was accomplished under ethanoldrop grinding at room temperature. The described catalyst was prepared successfully by a simple precipitation method and characterized by the Fourier transformed infrared absorption (FT-IR) spectroscopy, X-Ray diffraction (XRD) analytical technique, and scanning electron microscopy (SEM).

Results: A number of [1,3]dioxolo[g][1]benzopyran-6-carboxylic acids and pyrido[d]pyrimidine- 7-carboxylic acids were effectively synthesized in high yields (96-98%) within short reaction times (10-15 min). All synthesized compounds were well-characterized by IR, 1H and 13C NMR spectroscopy, and also by elemental analyses.

Conclusion: In summary, we have developed a very simple and impressive procedure for the synthesis of 8-aryl-8H-[1,3]dioxolo[4,5-g][1]benzopyran-6-carboxylic acids and 1,3-dimethyl- 2,4-dioxo-5-phenyl-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine-7-carboxylic acids as biologically interesting structures in the presence of CdO NPs as an efficient recyclable heterogeneous catalyst. The remarkable advantages for the offered protocol compared with traditional methods are short reaction time, good yields of the products, and the ease of operation with simple work-up procedure.

目的和目的：在过去的几十年中，纳米结构的过渡金属氧化物在化学转化中作为廉价、可用且极其有效的多相催化剂已经得到广泛证实。氧化镉纳米粒子 (CdO NPs) 的高导电性、高载流子浓度和更高的反应性使其成为纳米催化领域应用的潜在候选者。[1]苯并吡喃和吡啶并嘧啶衍生物构成主要类别的杂环化合物，它们具有广泛的生物活性。

材料和方法：在目前的工作中，我们报告了 8-芳基-8H-[1,3] 二氧杂环 [4,5-g][1] 苯并吡喃-6-羧酸和 1,3 -二甲基-2,4-二氧-5-苯基-1,2,3,4,5,8-六氢吡啶并[2,3-d]嘧啶-7-羧酸通过CdO NPs催化4-取代的环缩合反应苯亚甲基丙酮酸与 3,4-亚甲二氧基苯酚或 6-氨基-1,3-二甲基尿嘧啶，这是在室温下乙醇滴研磨下完成的。所描述的催化剂通过简单的沉淀法成功制备，并通过傅里叶变换红外吸收 (FT-IR) 光谱、X 射线衍射 (XRD) 分析技术和扫描电子显微镜 (SEM) 进行表征。

结果：在较短的反应时间内，以高产率 (96-98%) 有效合成了许多 [1,3]dioxolo[g][1] 苯并吡喃-6-羧酸和吡啶并[d]嘧啶-7-羧酸（10-15 分钟）。所有合成的化合物均通过 IR、1H 和 13C NMR 光谱以及元素分析进行​​了充分表征。

结论：总而言之，我们开发了一种非常简单且令人印象深刻的方法来合成 8-芳基-8H-[1,3] 二氧杂环 [4,5-g][1] 苯并吡喃-6-羧酸和 1,3 -二甲基-2,4-二氧-5-苯基-1,2,3,4,5,8-六氢吡啶并[2,3-d]嘧啶-7-羧酸作为在CdO NPs存在下具有生物学意义的结构作为一种高效的可回收多相催化剂。与传统方法相比，所提供的协议的显着优点是反应时间短、产品收率高、操作简便、后处理程序简单。