Palladium-catalyzed displacement of 2,6-dibromotoluene (I) with cyclopropylamine (II) affords N-cyclopropyl-3-bromo-2-methylaniline (III). Subsequent condensation of aniline (III) with diethyl ethoxymethylenemalonate (IV) produces the enaminomalonate (V), which is further cyclized to the quinolinecarboxylate (VI) in hot PPA.

5-Bromo-2-chloro-3-methylpyridine (VII) is treated with aqueous methylamine to yield the aminopyridine derivative (VIII), which is further acetylated to (IX) using acetic anhydride in pyridine. Stannylation of the bromopyridine (IX) by means of hexabutylditin in the presence of palladium catalyst gives rise to the tributylstannyl pyridine (X). This compound is then subjected to Stille coupling with the bromoquinoline (VI) to furnish the corresponding pyridyl quinoline adduct (XI). Basic hydrolysis of the ethyl ester group of (XI) provides the quinolinecarboxylic acid (XII). The N-acetyl group of (XII) is finally hydrolyzed under acidic conditions to give the title compound.