合成路线1

The diazonium salt (VI), prepared by diazotization of p-anisidine (V), was added to 4-methoxy-2-tert-butylphenol (VII) yielding the azo adduct (VIII). Protection of the phenolic hydroxyl group of (VIII) was carried out by alkylation with methoxymethyl chloride and NaH to give methoxymethyl ether (IX). Then, reductive cleavage of the diazo group of (IX) by hydrogenation over Pd/C furnished aniline (X) (1). Subsequent reaction of (X) with triphosgene and triethylamine in cold CH2Cl2 produced isocyanate (XI), which was condensed with amine (IV) to afford urea (XII). After acid deprotection of the methoxymethyl group of (XII), treatment with phosphoric acid in EtOH provided the title triphosphate salt.