Microwave‐assisted synthesis and evaluation of antimicrobial activity of 3‐{3‐(s‐aryl and s‐heteroaromatic)acryloyl}‐2H‐chromen‐2‐one derivatives

Abstract

in Wiley InterScience (www.interscience.wiley.com).The exploration of potential utilization of microwaves as an energy source for heterocyclic synthesis was herein investigated using condensation of 3-acetylcoumarin (1) with aromatic and heteroaromatic aldehydes to afford the corresponding aromatic chalcones (2a-j) and heteroaromatic chalcones (3a-e and 4a-e), respectively, in good to excellent yield within 1-3 min. The chemical structures were confirmed by analytical and spectral data. All the synthesized compounds were screened for their antibacterial activity and 3-{3-(4-dimethylaminophenyl)acryloyl}-2H-chromen-2-one (2i) was discovered to be the most active at minimum inhibitory concentration (MIC) value of 7.8 lg/mL.

Spectroscopic studies, DFT calculations, and cytotoxic activity of novel silver(I) complexes of hydroxy ortho-substituted-nitro-2H-chromen-2-one ligands and a phenanthroline adduct

“…Coumarins, a large class of benzopyrones, occur widely in nature and are the central moiety of many hundreds of synthetic compounds [1]. They have a rich medicinal chemistry and have been widely investigated as anticoagulants (warfarin, dicoumarol) [2], as antibiotics (novobiocin) [3], as antitumour, [4] and as antiviral compounds [5].…”

Microwave-assisted synthesis and antioxidant properties of hydrazinyl thiazolyl coumarin derivatives

“…It has been reported that the use of microwave heating is beneficial for 3-acetylcoumarin synthesis, allowing for low catalyst loadings and short reaction times to limit the generation of unwanted side products [33,34]. Although solvent-free conditions have been used for α-pyrone 3 formation under microwave irradiation [31,32] and conventional heating [36], in the presence of a catalytic amount of piperidine or l -proline, these give rise to widely varying reaction times, operating temperatures and thus chemical yields [31]. In our hands (entry 1), the solvent-free process resulted in a rapid rise of pressure and so was discarded in favour of the more reliable Leadbeater method, carried out in ethanol solvent, which has been reported to proceed in reasonable yield (67–81%) on multigram scale in sealed vessel microwave apparatus [33] and more recently in a large scale batch reactor [34].…”

Present status of quinoxaline motifs: Excellent pathfinders in therapeutic medicine

“…The antifungal screening of quinoxalinylhydrazones 111 [2], 112 [119], triazolo-113 [119] as well as Schiff base 114 [120] showed them to be promising agents against Candida albican. Sulfoxide derivative 115 was reported to be more effective than the reference drug metronidazole against Trichomonas vaginalis [121] while 116 inhibited the growth of Trichomonas vaginalis at MIC value of 6.25 µg/mL, after 24 h of incubation [121].…”