Regiospecific synthesis, antibacterial and anticoagulant activities of novel isoxazoline chromene derivatives

The synthesis and pharmacological evaluation of new series of 4-((3-aryl-4,5-dihydroisoxazol-5-yl)methoxy)-2H-chromen-2-ones 3a–f prepared by cycloaddition reaction using various arylnitrile oxides with the suitable 4-(allyloxy)-2H-chromen-2-one 2a are described. The 2-methyl-2,3-dihydrothieno[3,2-c]chromen-4-one 8 was also synthesized due to chemospecificity by the thio-Claisen rearrangement of 4-(allylthio)-2H-chromene-2-thione 7a. We also describe the new heterocyclic compounds 4-(R-thio)-2H-chromene-2-thiones 7a–d, 4-(2-thioxo-2H-chromen-4-ylthio) 5 and 4,4′-thiobis (2H-chromen-2-one) 6 which were prepared by a classical and PTC alkylation of 4-mercapto-2H-chromene-2-thione 4 with allylic halides.