合成路线1

N-Boc-L-4'-Aminophenylalanine-N-methylamide (VIII) was converted to the guanidine derivative (X) by reaction with pyrazole-N,N'-bis(benzyloxycarbonyl)carboxamidine (IX). After acidic Boc group cleavage in (IX), the resultant amino amide (XI) was coupled with the carboxylic acid (VII) to produce a diastereomeric mixture of amides, which were separated by column chromatography. The desired isomer (XII) was then treated with 95% aqueous trifluoroacetic acid to remove the tert-butyl ester group, yielding acid (XIII). Coupling of (XIII) with O-benzyl hydroxylamine furnished the O-benzyl hydroxamate (XIV). Finally, the benzyl and benzyloxycarbonyl protecting groups of (XIV) were removed by catalytic hydrogenation over Pd/C to afford the title compound.