Synthesis and evaluation of antiinflammatory and analgesic activities of a novel series of coumarin Mannich bases.

ABSTRACT

A novel series of coumarinyl Mannich bases (3a-1) have been synthesized by reacting 3-acetyl coumarin (1) with various substituted secondary amines (2a-1) in presence of paraformaldehyde. The structures of the newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR and HRMS (high resolution mass spectral) data. Title compounds were screened for in vivo acute anti-inflammatory activity using the carrageenan-induced rat paw edema assay model. Among the compounds tested, 3-[3-(diethylamino)propanoyl]-2H-chromen-2-one (3a)and 3-[3-(piperidine-1-yl) propanoyl]-2H-chromen-2-one (3c) showed 63.1 and 66.7% inhibition, respectively, as compared to the standard drug diclofenac (CAS 15307-86-5, 68.8%). These potent compounds showed encouraging analgesic andantipyretic activities.