Synthesis, characterization and evaluation of novel benzothiazole clubbed chromene derivatives for their anti-inflammatory potential

Abstract

A series of chromene derivatives (5a–f) were prepared by multistep synthesis process using 2-[3-phenyl prop-2-ene nitrile] 1,3-benzothiazole and dimedone using piperidine as catalyst in ethanol. The reaction was found to proceed via Knoevenagel condensation of aldehydes with benzothiazole, followed by the elimination to afford the 2-(benzo[d]thiazol-2-yl)-3-(aryl)acrylonitrile, which then undergoes Michael addition with 5,5-dimethyl-1,3-cyclohexanedione, followed by intramolecular O-cyclization to give the products. The structures of all novel constructed derivatives were corroborated by elemental analysis and spectral data (FT-IR, ¹H-NMR, ¹³C-NMR and Mass). Subsequently, the compounds were tested for their in-vivo anti-inflammatory activity. This study revealed that these synthesized derivatives tend to have significantly anti inflammatory activity and shall prove as structural templates in the design and development of new anti inflammatory drugs.

Graphical Abstract

Keywords:

• 2-Aminobenzenethiol
• chromene
• carrageenan-induced paw edema
• anti inflammatory

Acknowledgements

The authors are thankful to Department of Chemistry, Mohanlal Sukhadia University, Udaipur, Rajasthan and Pharmacy College, B. N. University for anti-inflammatory activity. The UGC Project, New Delhi is duly acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.