Nitric Acid → 5-Chloro-6-methyl-3-nitropyridin-2-amine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To stirred conc H2SO4 (70 mL) at 0° C. was added 45 (6.0 g, 41.8 mmol) in portions. To the resulting dark brown solution was added dropwise 70% HNO3 (3.5 mL, 54 mmol) at 0° C. After the addition, the reaction mixture was stirred at 50° C. under N2 for 2.5 h, cooled to room temperature and poured into crushed ice (about 700 g). The mixture was basified to pH 9 by the addition of 40% aq. NaOH dropwise with stirring and cooling (ice-water bath). The precipitate was filtered, washed with water (4×100 mL) and MeOH (3×25 mL), and dried to give 5.28 g (67%) of 46 as a yellow powder, mp 214°-5° C. (lit. 214°-6° C., Cress et al., J. Org. Chem. 93-6 (1976)). 1H NMR (DMSO-d6) δ2.445 (s, 3H), 8.011 (bs, 2H), 8.340 (s, 1H).

Herkunft & Nachweise