Mechanochemical synthesis of coumarins <i>via</i> Pechmann condensation under solvent-free conditions: an easy access to coumarins and annulated pyrano[2,3-<i>f</i>] and [3,2-<i>f</i>]indoles
作者:Ainur D. Sharapov、Ramil F. Fatykhov、Igor A. Khalymbadzha、Vladimir V. Sharutin、Sougata Santra、Grigory V. Zyryanov、Oleg N. Chupakhin、Brindaban C. Ranu
DOI:10.1039/d1gc04564d
日期:——
A green protocol has been developed for the synthesis of simple coumarins and linear pyrano[2,3-f] and [3,2-f]indoles by the reaction of phenol derivatives with β-ketoesters under ball milling at ambient temperature in the presence of methanesulfonic acid as a mild acid catalyst. The significant advantages of this procedure are high yields, scalability, no use of hazardous acids or solvents, shorter
已开发出一种绿色方案,用于通过苯酚衍生物与 β-酮酯在环境温度下球磨下的反应,合成简单的香豆素和线性吡喃并[2,3- f ] 和 [3,2 - f ] 吲哚。甲磺酸作为温和的酸催化剂。该方法的显着优势是高产率、可扩展性、不使用有害酸或溶剂、反应时间短、环境温度低、成本低以及无需柱色谱即可直接纯化。此过程与高 EcoScale 指标和低E因子相关联。与传统的 Pechmann 缩合过程相比,机械化学方案可合成具有优异区域选择性和高产率的吡喃吲哚。