Friedl鋘der cyclization between 2-aminobenzophenone (I) and 2-oxobutyric acid (II) by means of NaOMe in MeOH gives carboxylic acid (III), which is then converted into the corresponding acid chloride (IV) by reaction with SOCl2 in CH2Cl2. Finally, the target product is obtained by reaction of (IV) with N-methylbenzylamine (V) by means of Et3N.