Conjugation of amino acid O-methyl esters with AZT-5′-O-phosphorothioate and phosphorodithioate

Based upon 1,3,2-oxathia(-dithia)phospholane chemistry, 5′-O-derivatisation of AZT with the O-methyl esters of l-phenylalanine and l-tryptophan was performed and the corresponding 5′-aminoacidophosphoramidothioates or phosphoramidodithioates of AZT were obtained in satisfactory yield.