To provide a method for purifying 2',3'-didehydro-3'-deoxythymidine (d4T) used as an anti-HIV (human immunodeficiency virus) pharmaceutical.
This method for purifying the d4T comprises (a) reacting 5-metyluridine expressed by formula X with mesyl chloride in the presence of an organic base having a pKa value of 5.5 to 8.0, to mesylate hydroxy groups at the 2', 3', and 5' positions, and treating the mesylated compound with a hydroxide to synthesize 2,2'-anhydro-compound VIII, (b) substituting the 5'-mesyl group of the compound VIII with a benzoate anion, then hydrobrominating the substituted compound VIII, to synthesize 5'-benzoyl-2'-bromo-compound VI, and further subjecting the compound VI to reductive elimination reaction in the presence of a reduction metal, to form d4T 5'-benzoate III, (c) treating the compound III with butylamine and further treating the treated compound III with N-methylpyrrolidine and butyl acetate, to obtain d4T-NMPO solvate II, and (d) heating the d4T-NMPO solvate II in an alcoholic medium, to decompose the solvate II.
STARK DERRON R
BAKER STEPHEN R
QUINLAN SANDRA L
