Alternate Synthesis Route of 2-(Substituted Phenyl)-3,3a-dihydro-8H-pyrazolo[5,1-<i>a</i>]isoindol-8-ones via Chalcone-Based N-Formyl-pyrazolines
作者:Naseem Ahmed、Dharm Dev
DOI:10.1080/00397911.2011.606414
日期:2013.1.1
Abstract An alternate approach to 2-(substituted phenyl)-3,3a-dihydro-8H-pyrazolo[5,l-a] isoindol-8-ones via chalcone-based N-formyl-pyrazolines is described. N-Formyl-pyrazolines were prepared in excellent yield (81–96%) by the reaction of chalcones with hydrazine hydrate in the presence of formic acid, which undergoes intramolecular Friedel–Crafts acylation in the presence of trifluoroacetic acid
摘要 描述了通过基于查尔酮的 N-甲酰基-吡唑啉生成 2-(取代苯基)-3,3a-二氢-8H-吡唑并[5,1a] 异吲哚-8-酮的替代方法。通过查耳酮与水合肼在甲酸存在下的反应,在三氟乙酸(TFA)作为催化剂的存在下进行分子内弗瑞德-克来福特酰化反应,以优异的收率(81-96%)制备了 N-甲酰基-吡唑啉在乙腈中回流,以良好至极好的收率(74-94%)提供官能化的 2-(取代苯基)-3,3a-二氢-8H-吡唑并[5,1-a]异吲哚-8-酮。我们的合成路线避免了昂贵的试剂并显着提高了产量。图形概要