合成路线1

Itaconic acid mono-tert-butyl ester (IV) was prepared via esterification of itaconic acid (I) with methanol in the presence of an acidic ion exchange resin to form the mono-methyl ester (II), which was further converted to methyl tert-butyl ester (III) upon treatment with isobutylene and sulfuric acid. Subsequent hydrolysis of the methyl ester function of (III) using LiOH furnished mono-ester (IV). Reduction of acid (IV) to the primary alcohol (V) was accomplished using the NaBH4-I2 reagent. Michael addition of p-bromothiophenol (VI) to the unsaturated ester (V) provided the thioether adduct (VII). Mitsunobu coupling of alcohol (VII) with benzo[1,2,3]triazin-4-one (VIII) yielded the 3-substituted triazinone (IX). The biphenyl system (XI) was then obtained by Suzuki coupling of the aryl bromide (IX) with (4-chlorophenyl)tributyltin (X) in the presence of palladium tetrakis(triphenylphosphine) and lithium chloride. Trifluoroacetic acid-promoted cleavage of the tert-butyl ester group of (XI) gave acid (XII), which was subsequently coupled to O-allyl hydroxylamine (XIII) to afford the allyl hydroxamate (XIV). The O-allyl group was finally removed by treatment with tributyltin hydride and a palladium catalyst.