title: Efficient synthesis of 9,10-dihydropyrano[2,3-h]chromene-2,8-dione derivatives in ionic liquid and the study of their antioxidant activity.
abstract: Ionic liquid N,N,N',N'-tetramethylguanidinium trifluoroacetate (TMGT) has been applied as a green and reusable catalyst for the one-pot synthesis of 10-aryl substituted-9,10-dihydropyrano[2,3-h]chromene-2,8-diones via reaction of various aromatic aldehydes, 5,7-dihydroxycoumarin derivatives and Meldrum's acid. The reactions were rapid, clean and the products were prepared in good yield. The ionic liquid was stable during the reaction process and reused without significant loss of its activity. The synthesised compounds were evaluated for their antioxidant activity by a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay.
authors.affiliation: a Department of Chemistry, Firoozkooh Branch , Islamic Azad University , Firoozkooh , Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Lasemi
authors.affiliation: b Faculty of Chemistry, Department of Organic Chemistry , University of Mazandaran , Babolsar , Iran.
authors.forename: Razieh
authors.initials: R
authors.lastname: Azimi
authors.affiliation: b Faculty of Chemistry, Department of Organic Chemistry , University of Mazandaran , Babolsar , Iran.
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Azizi Amiri
mesh_terms: D000975:Antioxidants / Q000138:chemical synthesis* / Q000494:pharmacology*; D001713:Biphenyl Compounds; D002867:Chromones / Q000138:chemical synthesis* / Q000494:pharmacology*; D004146:Dioxanes; D007202:Indicators and Reagents; D052578:Ionic Liquids / Q000737:chemistry; D010084:Oxidation-Reduction; D010851:Picrates
chemical_list: C000618171:9,10-dihydropyrano(2,3-h)chromene-2,8-dione; D000975:Antioxidants; D001713:Biphenyl Compounds; D002867:Chromones; D004146:Dioxanes; D007202:Indicators and Reagents; D052578:Ionic Liquids; D010851:Picrates; C076489:Meldrum's acid; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: 5,7-dihydroxycoumarin; N,N,N',N'-tetramethylguanidinium trifluoroacetate; antioxidant activity; aromatic aldehyde; meldrum’s acid