合成路线1

In an alternative route to the title compound, dinitro derivative (XV) was converted into the benzofuroxan (XVI) by treatment with sodium azide in hot DMSO. Furazan ring opening by means of tert-butyl acetoacetate (XVII) under basic conditions generated the quinoxaline N,N'-dioxide (XVIII). The Pummerer-like rearrangement of the N-oxide (XVIII) in the presence of trifluoroacetic anhydride gave rise to the unstable trifluoroacetoxymethyl quinoxaline (XIX), which was further converted to bromide (XX) upon heating with LiBr in acetone. Alkylation of N,N-di-Boc-hydroxylamine (III) with bromide (XX) provided the protected O-alkyl hydroxylamine (XXI). Reduction of the remaining N-oxide group of (XXI) and simultaneous N-Boc groups cleavage by means of boron tribromide furnished quinoxaline (XXII). The fully deprotected quinoxaline (IX) was then obtained by acidic treatment of (XXII). Condensation of keto amide (XIII) with hydroxylamine (IX) in the presence of tetrabutylammonium bisulfate produced the oxime adduct (XXIII). Finally, the title compound was obtained by deformylation of (XXIII) under acidic conditions.