Method A, 0–2 °C, overnight; Method B, room temp., overnight; Method C, DMF, room temp., 1.5 h; Method D, THF, room temp., overnight; Method E, 0–2 °C, 1.5 h; Method F, room temp., 1.5 h; Method G, THF, room temp., overnight. ... Total yield of 2b and 3a (8:1 ratio deduced by 1 H NMR). ... Compound 3b was also obtained in 10 % yield. ... The use of AgPy 2 MnO 4 instead of KMnO 4 led to the desired N-alkyl-2,4-dinitroanilines 2a–g in 37–73 % yields ( ...