[Br:1][C:2]1[CH:3]=[C:4]([CH:9]=[C:10]([N+:12]([O-:14])=[O:13])[CH:11]=1)[C:5]([NH:7][CH3:8])=O.[N-:15]=[N+:16]=[N-:17].[Na+].S(OS(C(F)(F)F)(=O)=O)(C(F)(F)F)(=O)=O.C([O-])(O)=O.[Na+]>C(#N)C.C(OCC)(=O)C>[Br:1][C:2]1[CH:3]=[C:4]([C:5]2[N:7]([CH3:8])[N:17]=[N:16][N:15]=2)[CH:9]=[C:10]([N+:12]([O-:14])=[O:13])[CH:11]=1
3-bromo-N-methyl-5-nitrobenzamide (23.20 g, 90 mmol, 1 equiv.) was suspended in 200 ml of acetonitrile at 25° C. under nitrogen then sodium azide (5.82 g, 90 mmol, 1 equiv.) was added. Cooled to 0° C. then very slowly added triflic anhydride (15.07 ml, 90 mmol, 1 equiv.) dropwise via an addition funnel. The reaction became an amber solution. Worked up after 4 hours by adding 200 ml of sat'd NaHCO3 and stirred 10 minutes. Then added ethyl acetate and separated the layers. The ethyl acetate was rinsed twice with sat'd NaHCO3 then once with brine. The ethyl acetate was dried over MgSO4 then stripped in vacuo to give a dark amber oil which was stirred in 25 ml of ethyl acetate. After stirring 5 minutes, solids which precipitated were filtered off, and pumped under high vacuum to give 10.5 g of tan solids. The filtrate was stripped then purified over silica gel in 100% methylene chloride to obtain an additional 9.0 g of solids. By NMR both solids were identical for product and were combined.
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