Synthesis of 3-carboxylated Coumarins by Knoevenagel Condensation and Exploratory Anti-inflammatory Activity Evaluation by in vivo model

Coumarins are versatile organic compounds that possess multiple biological properties. Recently, their synthesis and biological activities have received a great deal of interest. We report the synthesis of four coumarins derived from the Knoevenagel condensation of o-vanillin aldehyde and dimethyl or diethyl malonate and further transesterification. The condensation was performed by a one pot procedure, and the yield reached 96-97%. Meanwhile, the transesterification procedure took place in two steps with a 60% yield. We also explored the anti-inflammatory activity of one of the derivatives by using the carrageenan-induced rat paw edema.