[CH3:1][NH:2][C:3](=O)[C:4]1[CH:9]=[C:8]([N+:10]([O-:12])=[O:11])[CH:7]=[C:6]([Br:13])[CH:5]=1.[N-:15]=[N+:16]=[N-:17].[Na+].FC(F)(F)S(OS(C(F)(F)F)(=O)=O)(=O)=O.C(=O)([O-])O.[Na+]>C(#N)C.C(OCC)(=O)C>[Br:13][C:6]1[CH:5]=[C:4]([C:3]2[N:2]([CH3:1])[N:17]=[N:16][N:15]=2)[CH:9]=[C:8]([N+:10]([O-:12])=[O:11])[CH:7]=1
A suspension of N-methyl-3-bromo-5-nitrobenzamide (23.2 g, 90 mmol) in acetonitrile (200 mL) wad treated with sodium azide (5.82 g, 90 mmol) and cooled to 0° C. Trifluoromethanesulfonic anhydride (15.1 mL, 90 mmol) was added dropwise very slowly. After the mixture was stirred for 4 hours, saturated aqueous sodium hydrogen carbonate was added and the mixture was stirred for 10 minutes. The mixture was extracted with ethyl acetate and the organic phase was washed twice with saturated aqueous sodium hydrogen carbonate, once with saturated sodium chloride, and dried over magnesium sulfate. Concentration provided a dark amber oil which was stirred in ethyl acetate (25 mL) to provide a precipitate, which was isolated by filtration and dried to provide a tan solid (10.5 g). The filtrate was purified by silica gel chromatography, eluting with dichloromethane, to provide additional solid (9.0 g, 76% total). 1H NMR (300 MHz, CDCl3) δ8.60 (s, 1H), 8.55 (s, 1H), 8.32 (s, 1H), 7.26 (s, 1H), 4.29 (s, 3H).
Wird geladen…
