Microwave-assisted solvent-free synthesis of biologically active novel heterocycles from 3-formylchromones

Abstract

A series of novel chromone derivatives have been synthesized employing 3-formylchromones and 5-acetyl-1,3-dimethylbarbituric acid as starting materials both under conventional heating method and microwave irradiation technique in good yields. The synthesized compounds were screened in vitro antibacterial activity against the representative panel of two Gram-positive bacteria and two Gram-negative bacteria. The synthesized compounds were also tested for their inhibitory action against three strains of fungus. The various compounds show potent inhibitory action against test organisms.

Chromone: A Valid Scaffold in Medicinal Chemistry

“…The presence of three electrondeficient carbons (C-2, C-4 and CHO) on the 3-formylchromone structure makes this compound an exceptional starting material for several nucleofilic additions, which in turn can lead to a great diversity of derivatives. Taking advantage of these features, several heterocyclic substituted chromones were obtained, namely with aza [294,295] , diaza [170,296] , oxa [297] and dithiazole [298][299][300][301][302] groups as well as vinyl chromone derivatives [303,304] (scheme 2.13).…”

Synthesis of heterocyclic analogs of isoflavone and homoisoflavone based on 3-formylchromone

“…Some pyrazolylchromone derivatives 39 were active against Gram-positive (Staphylococcus aureus, Bacillus subtilis) and Gram-negative (Escherichia coli, Salmonella typhimurium) bacteria and fungi strains (Candida albicans, Aspergillus niger, and Aspergillus fumigatus). 53,54 The treatment of nitrovinylchromones 40 with the generated in situ aromatic aldehyde N-methylhydrazones gave pyrazole isofl avone analogs 41 (Scheme 14). 55 The -Hydroxyiminoketones 47 reacted with 3-formylchromone 1a to give 3-(1-hydroxyimidazol-2-yl)chromones 48 (Scheme 18).…”

Benign Approaches for the Microwave‐assisted Synthesis of Five‐membered 1,2‐N,N‐heterocycles

“…Thus, the reaction of heterochalcones ( 22 ) with Br 2 in chloroform at room temperature afforded 2,3‐dibromodihydrochalcones ( 23 ) quantitative yields. Further, 2,3‐dibromodihydrochalcones ( 23 ) were converted to pyrazole derivative ( 24 ) in dry pyridine at room temperature and in a solvent‐free condition (Scheme ) .…”