21138-15-8Relevant academic research and scientific papers
Synthesis of 1-(3H)isobenzofuranone compounds by tin powder promoted cascade condensation reaction
Wang, Shangxian,Wang, Ke-Hu,Chang, Bo,Huang, Danfeng,Hu, Yulai
, (2021/03/31)
An efficient approach for the construction of phthalide compounds is developed through tin powder mediated cascade condensation reaction of 2-formylbenzoic acids with allyl bromides or α-bromoketone under mild reaction conditions. This method is easy to operate and can tolerate various functional groups to give the corresponding phthalides in good to excellent yields. The phthalides produced from α-bromoketone can be further transformed to 3,3a-dihydro-8H-pyrazolo[5, l-a]isoindol-8-one and 8H-pyrazolo[5, l-a]isoindol-8-one.
Alternate synthesis route of 2-(substituted phenyl)-3,3a-dihydro-8H- pyrazolo[5,1-a[isoindol-8-ones via chalcone-based n-formyl-pyrazolines
Ahmed, Naseem,Dev, Dharm
, p. 689 - 704 (2013/01/15)
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 (TFA) as a catalyst to afford functionalized 2-(substituted phenyl)-3,3a-dihydro-8H-pyrazolo[5,1-a]isoindol-8-ones in good to excellent yield (74-94%) at reflux in acetonitrile. Our synthetic route avoids expensive reagents and significantly improves yields.
