合成路线1

In an enantioselective synthesis of the (S)-enantiomer, asymmetric alkylation of the chiral N-butyryl oxazolidinone (I) with benzyl 5-bromomethyl-2-methoxybenzoate (II) in the presence of lithium hexamethyldisilazide leads to isomer (III) in high diastereomeric excess. Subsequent benzyl ester hydrogenolysis in (III) employing Pd/C affords carboxylic acid (IV), which is further converted to the mixed anhydride (V) with ethyl chloroformate and triethylamine. Coupling of anhydride (V) with 4-trifluoromethylbenzylamine (VI) furnishes the corresponding amide (VII). The chiral auxiliary is then removed from (VII) by hydrolysis with lithium peroxide to yield the target (S)-enantiomer.