NOTE: The preparation of isoxazole derivative of 4-hydroxycoumarin

摘要

A method for preparation of an isoxazole derivative of 4-hydroxycoumarin, 3-phenyl-5-(4-hydroxy-3-coumarinyl)-isoxazole has been described. The reaction se- quence includes addition of bromine to 3-cinnamoyl-4-hydroxycoumarin, and the subsequent treatment of the obtained dibromo derivative with 2 equivalents of sodium azide. Due to steric reasons, the azido group is introduced in the β-position with respect to the side chain carbonyl group, so that an isoxazole ring can be formed. The total yield of the reaction was 58/100.