合成路线1

Esterification of 5-iodosalicylic acid (I) with methanol and H2SO4 provides the methyl ester (II). Subsequent palladium-catalyzed coupling of (II) with 3-butyn-1-ol (III) yields adduct (IV). Alkylation of the phenolic hydroxyl group of (IV) with 1,2-dibromoethane affords the bromoethyl ether (V). The bromide group of (V) is then displaced with (R)-p-chlorobenzhydryl piperazine (VI) to produce the disubstituted piperazine (VII). Mitsunobu coupling of alcohol (VII) with phenoxycarbonylamino phenoxyformate (VIII) furnishes the protected N-hydroxy carbamate (IX). Finally, ammonolysis of the ester groups of (IX) gives rise to a mixture of the title N-hydroxyurea derivative, along with the analogous methyl ester (X), which can be separated by means of flash chromatography