Process for the synthesis and/or preparation of modafinil having a defined granulometry

Disclosed is a process for preparing modafinil having a granulometry wherein the ratio of median to mean is of 1:3 to 1:0.3 and median to mode is of 1:3 to 1:0.3, and having a granulometric median of between 2 and 60 micrometers, which comprises the steps of: (a) preparing a solution of DMSAM in a solvent, in which the concentration of DMSAM is of between 1 and 1.25 mol L-1; (b) contacting the solution obtained with NH3 at a temperature of between 15 Deg C and 65 Deg C and under a predetermined stirring; and (c) isolating the modafinil formed, wherein the stirring speed is predetermined in order to obtain said defined granulometry and granulometric median.