Alkylation of 1-(2-isopropoxyphenyl)piperazine (I) with 1-azido-3-(p-toluenesulfonyloxy)-2-propanol (II) in hot NMP gave (III). Subsequent hydrogenation of the azido group of (III) over Pd/C provided the intermediate amine (IV).
(S)-Epichlorhydrin (V) was treated with benzylamine to afford aminoalcohol (VI). After protection of the amino group of (VI) as the tert-butyl carbamate (VII) with Boc2O, displacement of the chlorine of (VII) with arylpiperazine (I) furnished (VIII). Deprotection of the N-Boc group of (VIII) by means of trifluoroacetic acid gave (IX). Then, the N-benzyl group of (IX) was removed by transfer hydrogenolysis employing ammonium formate and Pd/C to provide the intermediate amine (IV).
Condensation of 1,2,4-benzenetricarboxylic anhydride (X) with N,N-dimethyl-p-phenylenediamine (XI) in boiling AcOH produced phthalimide (XII). The title amide was then obtained by coupling of acid (XII) with amine (IV) in the presence of HATU, or EDC, HOBt and DMAP in dichloromethane.