A procedure for the alkylation of hydroxypyrones with alkyl halides in the presence of potassium hydroxide in dimethyl sulphoxide (DMSO) at ambient temperature has been described. The method supercedes in simplicity and efficiency to those previously reported. The alkylation has been found to be very effective especially with methyl or ethyl iodide or benzyl bromide. To prove the general applicability of the method some related 4­hydroxycoumarins have also been alkylated.


M IQBAL ,M SIDDIQ ,M A MUNAWAR ,