Novel Coumarin Isoxazoline Derivatives: Synthesis and Study of Antibacterial Activities

A highly efficient and mild protocol for the syntheses of ethyl-3- [7-benzyloxy-4-methyl-2-oxo-2H-8-chromenyl]-5-aryl-4,5-dihydro-4- isoxazole carboxylates and ethyl-3-[7-benzyloxy-3-chloro-4-methyl-2- oxo-2H-8-chromenyl]-5-aryl-4,5-dihydro-4-isoxazole carboxylates in good yields via [3 þ 2] cycloaddition of in situ–generated nitrile oxides from 7-benzyloxy-4-methyl-coumarin hydroxymoylchlorides and 7-benzyloxy-3-chloro-4-methyl-coumarin hydroxymoylchlorides respectively with ethyl-3-aryl prop-2-enoate has been developed. The new compounds are screened for antibacterial activity.