Efficient solvent free synthesis of tetrahydrobenzo[<i>a</i>]xanthene-11-one derivatives using nano-AlPO₄/Ti (IV) as a green, heterogeneous and reusable catalyst

A new green protocol has been developed for synthesis of tetrahydrobenzo[a]xanthen-11-ones via a three component, one-pot condensation reaction of dimedone, β-naphthol and aromatic aldehydes using nano-AlPO4/Ti (IV) (NAP-Ti(IV)) as a reusable and novel catalyst at 90 °C under solvent-free condition. Short reaction times, high yields, scale up and easy work-up are advantages of this protocol. The prepared nano-AlPO4/Ti(IV) was fully characterized by EDX, XRD, SEM, IR analysis. The obtained tetrahydrobenzo[a]xanthen-11-ones were characterized by various methods such as FT-IR, 1HNMR.本研究开发了一种新型绿色合成工艺，以纳米磷酸铝/四价钛（nano-AlPO4/Ti(IV)，缩写NAP-Ti(IV)）为可重复使用的新型催化剂，在90℃无溶剂条件下，通过达米酮（dimedone）、β-萘酚（β-naphthol）与芳香醛（aromatic aldehydes）的三组分一锅缩合反应，合成四氢苯并[a]呫吨-11-酮（tetrahydrobenzo[a]xanthen-11-ones）。该工艺具备反应时长较短、产物收率高、可放大制备以及后处理简便等优势。所制备的纳米磷酸铝/四价钛（NAP-Ti(IV)）通过能谱（EDX）、X射线衍射（XRD）、扫描电子显微镜（SEM）与红外光谱（IR）等分析手段完成了全面表征。所得四氢苯并[a]呫吨-11-酮则通过傅里叶变换红外光谱（FT-IR）、氢核磁共振波谱（¹HNMR）等多种方法完成表征。