[C:1]([C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=1[NH2:11])([CH3:4])([CH3:3])[CH3:2].[N+:12]([O-])([O-:14])=[O:13].[K+]>S(=O)(=O)(O)O>[C:1]([C:5]1[CH:10]=[CH:9][C:8]([N+:12]([O-:14])=[O:13])=[CH:7][C:6]=1[NH2:11])([CH3:4])([CH3:2])[CH3:3]To a cooled solution of sulfuric acid (90%, 50 mL) was added dropwise 2-tert-butyl-phenylamine (4.5 g, 30 mmol) at 0° C. Potassium nitrate (4.5 g, 45 mmol) was added in portions at 0° C. The reaction mixture was stirred at 0-5° C. for 5 min, poured into ice-water and then extracted with EtOAc three times. The combined organic layers were washed with brine and dried over Na2SO4. After removal of solvent, the residue was purified by recrystallization using 70% EtOH—H2O to give 2-tert-butyl-5-nitroaniline (3.7 g, 64%). 1H NMR (400 MHz, CDCl3) δ 7.56 (dd, J=8.7, 2.4 Hz, 1H), 7.48 (d, J=2.4 Hz, 1H), 7.36 (d, J=8.7 Hz, 1H), 4.17 (s, 2H), 1.46 (s, 9H); HPLC ret. time 3.27 min, 10-99% CH3CN, 5 min run; ESI-MS 195.3 m/z (MH+).
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