合成路线1

Suzuki coupling of methyl 2-bromo-4-nitrobenzoate (I) with 1-naphthylboronic acid (II) provided naphthyl benzoate ester (III). The nitro group of (III) was then reduced by hydrogenation over Pd/C yielding aniline (IV). Diazotization of (IV), followed by reaction with KI gave aryl iodide (V), and subsequent halogen displacement by KCN in the presence of palladium catalyst afforded nitrile (VI). After basic hydrolysis of the methyl ester of (VI), the resulting carboxylic acid (VII) was coupled to L-leucine methyl ester (VIII) using EDC and HOBt to yield amide (IX). Reduction of the nitrile group of (IX) with NaBH4 and CoCl2 gave the corresponding amine, which was isolated as the tert-butyl carbamate (X) upon treatment with Boc2O.