Synthesis and biological evaluation of some 4‐(isoxazolinyl or 1,2,4‐oxadiazolyl) coumarins

Abstract

Abstract Reaction of compound 3 with nitrile oxide 4a affords compounds 5a and 6 in 73% and 3% yield respectively, while reaction of 3 with 4b affords only compound 5b (85%). Reactions of compound 8 with the nitrile oxides 4a,b result in compounds 9a,b . The compound 10 , prepared from 1 and O ‐methylhydroxylamine, reacts with nitrile oxide 4b to give the oxadiazole derivative 12 . The above referred coumarins are screened for antiinflammatory activity in vivo using the carrageenin rat paw edema and in vitro through their antiproteolytic activity and their ability to inhibit β‐glucuronidase and 12‐Lipoxygenase.