Process for the large scale production of Stavudine

An improved process for the preparation of Stavudine comprising the steps of:

• a) heating 3′,5′-anhydrothymidine in acetonitrile in potassium t-butoxide;
• b) adding methanol to the reaction mass;
• c) neutralizing with an acid and filtering the reaction mass to remove the insoluble salts;
• d) evaporating the solvent from the filtered mass;
• e) dissolving the crude Stavudine in an organic solvent which is selected from alcohol or ketone, wherein the alcohol is selected from the group consisting of methanol, ethanol, n-propanol, 2-propanol, 1-butanol and isobutanol, and the ketone is selected from the group consisting of acetone, methyl ethyl ketone and methyl isobutyl ketone;
• f) treating with a solvent selected from the group consisting of N,N-Dimethylpropyleneurea, N,N-Dimethylethyleneurea and their mixtures thereof in an organic solvent to precipitate corresponding Stavudine solvate which is isolated from the reaction mixture;
• and
• g) desolvating the Stavudine solvate in a solvent is selected from water, alcohol, or ketone, wherein the alcohol is selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and isobutanol, and the ketone is selected from the group consisting of acetone, methyl ethyl ketone and methyl isobutyl ketone.