Condensation of isatin (I) with 2-methoxyacetophenone (II) in the presence of KOH afforded quinolinecarboxylic acid (III). Subsequent demethylation of the ether function of (III) with refluxing 57% HI gave (IV), which was then condensed with (S)-1-phenylpropyl amine (V) using DCC and HOBt to yield the title amide.

The quinolinecarboxylic acid (III) was obtained by the Pfitzinger reaction of isatin (I) with 2-methoxyacetophenone (II) in ethanolic KOH at 80 C. Subsequent methyl ether cleavage in (III) using concentrated HI provided 3-hydroxy-2-phenylquinoline-4-carboxylic acid (IV). Coupling of acid (IV) with (S)-1-phenylpropylamine (V) by means of DCC and HOBt gave amide (VI). Ester (VIII) was then obtained by alkylation of the 3-hydroxy quinoline (VI) with ethyl bromoacetate (VII) in the presence of K2CO3 and KI. Finally, hydrolysis of the ethyl ester (VIII) with refluxing HCl afforded the corresponding carboxylic acid.