Nitric Acid → 5-Bromo-4-chloro-3-nitropyridin-2-amine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

5-Bromo-4-chloro-pyridin-2-ylamine (0.640 g, 3.0 mmol) was added in portions to conc. H2SO4 (6 ml) while the temperature kept at −10° C. The reaction mixture was then stirred at −10° C. for 15 min. The resulting solution was then heated at 55° C. and HNO3 (208 μL, 3.2 mmol) was added dropwise while the temperature was kept at 55° C.-60° C. maximum. The reaction mixture was stirred at 55° C. for 30 min then cooled to room temperature and poured slowly into ice (20 g). The pH was adjusted to 7 with 40% aqueous NaOH. The precipitated product was filtered, washed with water (20 ml) and dried in vacuo over P2O5 for 16 h to give the title compound as a yellow solid (0.580 g). 0.48 g was further purified by chromatography (hexane/ethyl acetate; v/v 7:3) to give the title compound as a yellow solid (0.287 g); 1H-NMR (250 MHz, CDCl3) 8.29 (s, 1H, 6-H).

Herkunft & Nachweise