Synthetic Route of 59489-71-3, These common heterocyclic compound, 59489-71-3, name is 2-Amino-5-bromopyrazine, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
Preparation c-120 5-Bromo-pyrazin-2-ol Sodium nitrite (1,35 g, 19.53 mmol) was added portionwise to concentrated sulfuric acid (9.8 mL) at 0 C. The mixture was heated at 50 C. until all of the sodium nitrite had dissolved and the mixture was again cooled to 0 C. A solution of 5-bromo-pyrazin-2-ylamine (2.57 g, 14.68 mmol) in concentrated sulfuric acid (14.7 mL) was added dropwise to the nitronium solution at 0 C. The ice bath was removed, the mixture warmed to ambient temperature and stirred for 15 minutes before heating to 45 C. for seven minutes. After cooling to ambient temperature, the mixture was poured slowly with precaution into crushed ice water (100 mL). The aqueous phase was neutralized to pH 4 with 20% aqueous sodium hydroxide then extracted with ethyl acetate (3*100 mL). The combined organic extracts were washed with water (50 mL), dried (anhydrous magnesium sulfate), filtered, and evaporated to afford the title compound (1.88 g, 73%) as a yellow solid. 1H NMR (CDCl3, 300 MHz): delta 8.07 (1H, s), 7.62 (1H, d, J=3.0 Hz).
Statistics shows that 2-Amino-5-bromopyrazine is playing an increasingly important role. we look forward to future research findings about 59489-71-3.
Reference:
Patent; Pfizer Inc; US2005/187266; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem