合成路线1

NXY-059 is synthesized by condensation of N-tert-butylhydroxylamine (I) or its acetate or hydrochloride salts and disodium benzaldehyde-2,4-disulfonate (II) directly in refluxing MeOH or mixtures of MeOH/water or i-PrOH/MeOH/water or by means of MeONa in refluxing MeOH/water or i-PrOH/MeOH/water. N-tert-butylhydroxylamine (I) can be prepared as follows: a) Reduction of 2-methyl-2-nitropropane (III) with either Zn in HOAc/EtOH or aluminum foil and HgCl2 in EtOH/ether/H2O. b) Condensation of benzaldehyde (IV) with tert-butyl-amine (V) in refluxing toluene provides N-benzylidene-N-tert-butylamine (VI), which is oxidized with meta-chloroperbenzoic acid and Na2CO3 in water/toluene/ EtOH to furnish the phenyloxaziridine derivative (VII). Finally, the oxaziridine ring of (VII) is opened by treatment with H2SO4/HOAc in EtOH/H2O. c) Heating of the phenyloxaziridine derivative (VII) at 130 C gives N-tert-butylphenylnitrone (VIII), which is finally treated with H2SO4/HOAc in toluene. Disodium benzaldehyde-2,4-disulfonate (II) can be obtained as follows: a) Heating of 2,4-dichlorobenzaldehyde (IX) with sodium sulfite at 170 °C in water in water, followed by oxidation with sodium hypochlorite. b) Reaction of 2,4-dichlorobenzal chloride (X) with sodium sulfite and Na2CO3 or NaHCO3 at 170 C in water, followed by oxidation with sodium hypochlorite.