An Efficient One-pot Synthesis of Dihydropyrano[c]chromenes and Amino-2-chromenes under Solvent-free Conditions
作者:Davood Habibi、Atefeh Shamsian
DOI:10.3184/174751913x13639572643562
日期:2013.4
in the three-component condensation reaction of aldehydes and malononitrile with α- or β-naphthol or 4-hydroxycoumarin. The products, amino-4H-chromenes and dihyropyrano[c]chromenes respectively, were obtained under mild conditions without any additional organic solvents in good to excellent yields and short reaction times. The catalyst could be recycled several times with only slight loss of activity
Synthesis of pyranopyrazoles, benzopyrans, amino-2-chromenes and dihydropyrano[c]chromenes using ionic liquid with dual Brønsted acidic and Lewis basic sites
efficient ionicliquid with both Brønstedacidic and Lewis basic sites, namely 1,4-dimethyl-1-(4-sulphobutyl)piperazinium hydrogen sulphate (IL1), was synthesised and characterised. IL1 is a “green”, homogeneous and reusablecatalyst for: i) the synthesis of pyranopyrazoles (Va-Vj)and benzopyrans (VIa-VIj and VIIa-VIIf) at ambient temperature under solvent-free conditions and ii) the synthesis of amino-2-chromenes