An efficient procedure for the synthesis of coumarin derivatives using TiCl4 as catalyst under solvent-free conditions
作者:Hassan Valizadeh、Abbas Shockravi
DOI:10.1016/j.tetlet.2005.03.124
日期:2005.5
titanium(IV) chloride as a catalyst to promote the Pechmann condensation reaction with a range of phenols and β-keto esters is described.The reaction was carried out by addition of TiCl4 to a mixture of the phenol and the β-keto ester with thorough stirring in the absence of a solvent and represents an improvement on the classical Pechmann conditions. The yields of coumarins obtained via this novel protocol
描述了氯化钛(IV)催化与一系列酚和β-酮酸酯进行Pechmann缩合反应的能力。该反应是通过将TiCl 4添加到酚和β-酮的混合物中进行的在没有溶剂的情况下充分搅拌下得到的酮酸酯,代表了对经典Pechmann条件的改进。通过该新颖方案获得的香豆素的产率明显高于使用常规方法的香豆素的产率,并且反应持续时间减少至数分钟甚至数秒。