Synthesis and bio-evaluation of novel 7-hydroxy coumarin derivatives via Knoevenagel reaction

• Published in: Research on chemical intermediates Vol. 41; no. 2; pp. 1115 - 1133
• Main Authors: Darla, Mark Manidhar, Krishna, Balam Sateesh, Umamaheswara Rao, K., Reddy, N. Baktavathsala, Srivash, Manoj Kumar, Adeppa, K., Sundar, Ch. Syama, Reddy, Cirandur Suresh, Misra, Krishna
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.02.2015
• Subjects: Catalysis; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Physical Chemistry; Cyano acetamide derivatives; Knoevenagel reaction; Fluconazole; Norfloxacin
• ISSN: 0922-6168; 1568-5675
• DOI: 10.1007/s11164-013-1258-1

Coumarin and 7-hydroxy coumarins have great significance as natural fragrances, having a characteristic odour like vanilla beans and their hydroxy position at 7 has importance in biosynthesis. Treatment of 8-formyl-7-hydroxy coumarin with N,N -disubstituted cyano acetamides in the presence of piperidine afforded novel 8-substituted-7-hydroxy coumarin derivatives. Their structures were characterized by IR, 1 H, 13 C NMR, mass spectral and elemental analysis data. Two out of these 12 compounds, i.e. 2-Cyano-3-(7-hydroxy-2-oxo-2H-chromen-8-yl)- N -[2-(2-methoxy-phenoxy)-ethyl]-acrylamide and 2-Cyano- N -(2,5-dihydro-thiazol-2-yl)-3-(7-hydroxy-2-oxo-2H-chromen-8-yl)-acryl amide showed enhanced in vitro antifungal activity against Candida albicans and Aspergillus niger vis-à-vis standard, i.e. fluconazole, and enhanced in vitro antibacterial activity against Escherichia coli , Staphylococcus aureus , and Pseudomonas aeruginosa vis-à-vis standard, i.e. norfloxacin. Graphical Abstract .