The present invention provides novel methods for the synthesis of racemic
and enantiomers of modafinil via microbial oxidation-amidation
transformation. The methods include the successive oxidation-amidation of
benzhydrylsulfanyl carboxylic acid to produce racemic and enantiomers of
modafinil using at least one microorganism of yeast, bacteria, or fungus.
Also disclosed are pharmaceutical compositions of racemic and enantiomers
of modafinil along with their use in the treatment of diseases, including
attention deficit hyperactivity disorder and drug addiction.