Background: Nanoscale metal oxide catalysts have been extensively employed in organic reactions because they have been found to influence the chemical and physical properties of bulk material. The chromene (benzopyran) nucleus constitutes the core structure in a major class of many biologically active compounds, and interest in their chemistry consequently continues because of their numerous biological activities. The xanthene (dibenzopyran) derivatives are classified as highly significant compounds which display a number of various bioactive properties. Pyrimidinones have also gained interest due to their remarkable biological utilization, such as antiviral, antibacterial, antihypertensive, antitumor, and calcium blockers effects.

Objective: The aim of this work presented herein was to prepare activated carbon/MoO3 nanocomposite and explore its role as a green and recyclable catalyst for the synthesis of chromeno[d]pyrimidinediones and xanthenones under ethanol-drop grinding at room temperature.

Methods: The activated carbon/MoO3 nanocomposite was prepared successfully via a simple route in which the carbonization of gums as new natural precursors was used for the synthesis of activated carbon. This nanocomposite was then effectively used in a reaction of 3,4-methylenedioxyphenol, aromatic aldehydes, and active methylene compounds, including 1,3-dimethylbarbituric acid and dimedone, to synthesize a series of chromeno[d]pyrimidinediones and xanthenones in high yields. The synthesized catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), Powder x-ray diffractometry (XRD), Scanning electron microscope (SEM), Raman spectroscopy, and also by TGA analysis. Confirmation of the structures of compounds 5(a-g) and 6(a-g) were also established with IR, 1H NMR, and 13C NMR spectroscopic data and also by elemental analyses.

Results: A number of 6,8-dimethyl-10-phenyl-6,10-dihydro-7H-[1,3]dioxolo[4´,5´:6,7]chromeno[2,3- d]pyrimidine-7,9(8H)-diones and 7,7-dimethyl-10-(4-methylphenyl)-6,7,8,10-tetrahydro-9H-[1,3]dioxolo[ 4,5-b]xanthen-9-ones were effectively synthesized using activated carbon/MoO3 nanocomposite (0.05 gr) as a catalyst under ethanol-drop grinding at room temperature. The desired products were obtained in high yields (93-97%) within short reaction times (15-20 min).

Conclusion: This paper investigates the catalytic potential of the synthesized activated carbon/MoO3 nanocomposite for the preparation of chromeno[d]pyrimidinediones and xanthenones under the ethanol-drop grinding procedure. The mildness of the reaction conditions, high yields of products, short reaction times, experimental simplicity, and avoiding the use of harmful solvents or reagents makes this procedure preferable for the synthesis of these compounds.

背景：纳米级金属氧化物催化剂已被广泛用于有机反应，因为已发现它们会影响散装材料的化学和物理性质。色烯（苯并吡喃）核构成了许多生物活性化合物的主要类别的核心结构，由于其众多的生物活性，因此对其化学的兴趣继续存在。呫吨（二苯并吡喃）衍生物被归类为具有多种生物活性特性的非常重要的化合物。嘧啶酮还因其显着的生物利用而引起了人们的兴趣，例如抗病毒、抗菌、抗高血压、抗肿瘤和钙阻滞剂作用。

目的：本文提出的这项工作的目的是制备活性炭/MoO3 纳米复合材料，并探索其作为绿色和可回收催化剂的作用，用于在室温下乙醇滴磨下合成色基[d]嘧啶二酮和呫吨酮。

方法：以树胶的碳化为新的天然前驱体合成活性炭，通过简单的途径成功制备了活性炭/MoO3纳米复合材料。然后，该纳米复合材料有效地用于 3,4-亚甲基二氧基苯酚、芳香醛和活性亚甲基化合物（包括 1,3-二甲基巴比妥酸和二甲酮）的反应，以高产率合成一系列色诺[d]嘧啶二酮和呫吨酮。通过傅里叶变换红外光谱 (FT-IR)、粉末 X 射线衍射 (XRD)、扫描电子显微镜 (SEM)、拉曼光谱以及 TGA 分析对合成的催化剂进行了表征。还通过 IR、1H NMR 和 13C NMR 光谱数据以及元素分析确定了化合物 5(ag) 和 6(ag) 的结构。

结果：许多 6,8-二甲基-10-苯基-6,10-二氢-7H-[1,3]dioxolo[4´,5´:6,7]chromeno[2,3-d]pyrimidine- 7,9(8H)-二酮和 7,7-二甲基-10-(4-甲基苯基)-6,7,8,10-四氢-9H-[1,3]dioxolo[4,5-b]xanthen-使用活性炭/MoO3纳米复合材料（0.05克）作为催化剂，在室温下乙醇滴磨下有效地合成了9-ones。在短反应时间（15-20 分钟）内以高产率（93-97%）获得所需产物。

结论：本文研究了合成的活性炭/MoO3 纳米复合材料在乙醇滴磨法下制备色基[d]嘧啶二酮和呫吨酮的催化潜力。反应条件温和，产物收率高，反应时间短，实验简单，避免使用有害溶剂或试剂，使该程序更适合合成这些化合物。