Quaternization of 4-pyridylcarbinol (I) by means of iodoethane provided pyridinium salt (II), which was reduced with NaBH4 to the tetrahydropyridine (III). Subsequent Mitsunobu coupling of (III) with 1-acetyl-6-bromo-2,3-dihydro-1H-indol-5-ol (IV) afforded ether (V). Intramolecular cyclization of (V) to the spiro compound (VI) was effected by treatment with tributyltin hydride and azobis(isobutyronitrile). The acetamide function of (VI) was then hydrolyzed by refluxing with HCl in H2O-EtOH to furnish intermediate diamine (VII).

Palladium-catalyzed coupling of phenyloxadiazol derivative (VIII) with 4-boronobenzoic acid (IX) yielded biphenyl (X). Further treatment of (X) with SOCl2 afforded acid chloride (XI). This was finally condensed with amine (VII) to provide the title carboxamide.