[Cl:1][C:2]([Cl:11])([Cl:10])[C:3]([C:5]1[NH:6][CH:7]=[CH:8][CH:9]=1)=[O:4].[N+:12]([O-:15])(O)=[O:13].[CH:16](O)(C)C>C(OC(=O)C)(=O)C>[N+:12]([C:8]1[CH:9]=[C:5]([C:3](=[O:4])[C:2]([Cl:1])([Cl:10])[Cl:11])[N:6]([CH3:16])[CH:7]=1)([O-:15])=[O:13]To a well stirred solution of trichloroacetyl chloride (1 kg, 5.5 mole) in 1.5 liter ethyl ether in a 12 liter flask was added dropwise over a period of 3 h a solution of N-methylpyrrole (0.45 kg, 5.5 mole) in 1.5 liter anhydrous ethyl ether. The reaction was stirred for an additional 3 hours and quenched by the dropwise addition of a solution of 400 g potassium carbonate in 1.5 liters water. The layers were separated and the ether layer concentrated in vacuo to provide 2-(trichloroacetyl)pyrrole (1.2 kg, 5.1 mol) as a yellow crystalline solid sufficiently pure to be used without further purification. To a cooled (−40° C.) solution of 2-(trichloroacetyl) pyrrole (1.2 kg, 5.1 mol) in acetic anhydride (6 L) in a 12 L flask equipped with a mechanical stirrer was added 440 mL fuming nitric acid over a period of 1 hour while maintaining a temperature of (−40° C.). The reaction was carefully allowed to warm to room temperature and stir an additional 4 h. The mixture was cooled to −30° C., and isopropyl alcohol (6 L) added. The solution was stirred at −20° C. for 30 min during which time a white precipitate forms. The solution was allowed to stand for 15 min and the resulting precipitate collected by vacuum filtration.
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