Glycerol: green solvent used at the synthesis of flavones

A. SATHICQ; E. ALARCÓN; A. VILLA; P. VÁZQUEZ; G. ROMANELLI

Foz do Iguaçu

Conferencia; 4th International IUPAC Conference on Green Chemistry ? 4th ICGC ? August 25-29, 2012-Foz do Iguaçu, Brazil.; 2012

Flavones constitute a large number of natural products. They exhibit diverse pharmacological activities, for example, antibacterial, antifungal, anticancer, gastro-protective and antioxidant [1]. One of the most commonly used methods for the synthesis of flavones consists of the cyclodehydration of 1-(2-hydroxyphenyl)-1,3-diketones (scheme 1). This is usually a catalyzed reaction and it has been performed in different media. Some reaction conditions employed were the use of excess of sulfuric acid in glacial acetic acid. All these reported methods suffer from strong acidic conditions, prolonged reaction times, low yields and high cost of the reagents [2]. In this way, the use of HPAs allows to obtain high yields and short reaction times, avoiding corrosion and environmental pollution. Glycerol, obtained in high amounts from biodiesel production, is non-toxic and has promising physical and chemical properties as an alternative safer solvent [3]