Glycerol: A Promising Benign Solvent for Catalyst Free One‐Pot Multi‐Component Synthesis of Pyrano[2, 3‐c]pyrazoles and Tetrahydro‐benzo[b]pyrans at Ambient Temperature. Issue 33 (22nd November 2017)

• Record Type: Journal Article
• Authors: Abdel Hamid, Afaf; Abd‐Elmonem, Mohamed; Hayallah, Alaa M.; Abo Elsoud, Fatma A.; Sadek, Kamal U.
• Is Part Of: ChemistrySelect. Volume 2:Issue 33(2017)
• Page Start: 10689
• Page End: 10693
• Publication Date: 2017-11-22
• Subjects: Ambient temperature -- Glycerol -- Multi-component reaction -- Pyrano[2, 3-c]pyrazole -- Tetrahydrobenzo[b]pyran; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201702011
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: A simple and efficient synthesis of 6‐amino‐5‐cyano‐4‐aryl‐1, 4‐dihydropyrano[2, 3‐c]pyrazoles and 2‐amino‐3‐cyano‐4‐aryl‐7, 7‐dimethyl‐5, 6, 7, 8‐tetrahydrobenzo[b]pyrans has been developed that involves a four‐component reaction of aromatic aldehydes, malononitrile, hydrazine hydrate or phenyl hydrazine and 1, 3‐dicarbonyl compounds using glycerol as both solvent and catalyst at ambient temperature. Several advantages have been achieved such as high yields, facile conducting reactants or working up products, high Eco Scale, atom economy and the absence of toxic or hazardous catalysts or solvents. Abstract : We have developed an efficient synthesis of 6‐amino‐5‐cyano‐4‐aryl‐1, 4‐dihydropyrano[2, 3‐c]pyrazoles via a four component reaction of aromatic aldehydes, malononitrile, hydrazine hydrate and ethyl acetoacetate and 2‐amino‐3‐cyano‐4‐aryl‐7, 7‐dimethyl‐5, 6, 7, 8‐tetrahydrobenzo[b]pyrans via a three component reaction of aromatic aldehydes, malononitrile and Dimedone using Glycerol as both solvent and catalyst at ambient temperature. This method is of several advantages such green, high Eco Scale, atom economy and can be utilized for the synthesis of a large variety of essential polyfunctionally substituted Heterocycles.