Enantioselective Synthesis of Modafinil Drug using Chiral Complex of Titanium and Diethyltartarate

Modafinil (Diphenyl methyl Sulfinyl acetamid) is used clinically in the treatment of narcolepsy and sleeping disorders. The synthesis of R-modafinil, have started with the reaction of benzhydrol and thioglycolic acid in trifluoroacetic acid to afford benzhydryl sulfanyl acetic acid. The reaction of acid with thionyl chloride in benzene followed by treatment with ammonium hydroxide gave acetamide. The process occurs at room temperature in toluene as a solvent and in the presence of a bidendate diethyltartarate–titanium isopropoxide complex as chiral catalyst. The reaction using this catalyst exhibits very good yield and appropriate enantioselectivity. The obtained products were characterized with FT-IR, 1 H NMR, 13C NMR, and mass spectral. The ee of the obtained sulphoxide has been determined by high performance liquid chromatography (HPLC).