4-Iodophenol (I) is alkylated with 1,2-dibromoethane (II) to afford 1-(2-bromoethoxy)-4-iodobenzene (III). Subsequent palladium-catalyzed coupling of aryl iodide (III) with 3-butyn-1-ol (IV) furnishes the phenylbutynol adduct (V), which is further hydrogenated in the presence of Pd/C to the saturated alcohol (VI). Condensation of the alkyl bromide (VI) with (R)-p-chlorobenzhydrylpiperazine (VII) produces the dialkylated piperazine (VIII). Then, Mitsunobu coupling of arylbutanol (VIII) with phenoxycarbonylaminophenoxyformate (IX) leads to the protected hydroxamic acid (X). This is finally treated with methanolic ammonia to provide the title N-hydroxyurea derivative.

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

Alkylation of 4-iodophenol (I) with 1,4-dibromobutane (II) provides ether (III). Subsequent palladium-catalyzed coupling between aryl iodide (III) and 3-butyn-1-ol (IV) leads to adduct (V). Reaction of bromide (V) with difluorobenzhydryl piperazine (VI) then gives (VII). Alcohol (VII) is subjected to Mitsunobu coupling with N,O-bis(phenoxycarbonyl)hydroxylamine to furnish the N-alkylated hydroxylamine derivative (VIII). This is finally reacted with methanolic ammonia to generate the title N-hydroxyurea compound.

A related method for the synthesis of the title compound has been reported. After esterification of 5-iodosalicylic acid (I), the methyl ester (II) is reacted with 1,2-dibromoethane to give bromide (III). Coupling of aryl iodide (III) with 3-butyn-1-ol (IV) leads to adduct (V). Displacement of bromide (V) with (R)-p-chlorobenzhydryl piperazine (VI) furnishes piperazine (VII). Then, ester group ammonolysis in (VII) leads to amide (VIII). Coupling of alcohol (VIII) with phenoxycarbonylamino phenoxyformate (IX) under Mitsunobu conditions furnishes the protected N-hydroxy carbamate (X). Finally, treatment of (X) with methanolic ammonia provides the desired N-hydroxyurea derivative