Application of 24241-18-7, A common heterocyclic compound, 24241-18-7, name is 2-Amino-3,5-dibromopyrazine, molecular formula is C4H3Br2N3, 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.
18b (3.0 g, 12 mmol) was added into acetic acid (20 mL) and concentrated sulfuric acid (4 mL) under ice bath. To this mixture was added a pre-prepared solution of NaNO2 (1.65 g, 24 mmol) in water (10 mL). The reaction mixturewas stirred at room temperature for 3 h, and then poured into ice water (100 g). The precipitate was collected by filtrated, washed with water and dried to give an off-white solid (1.8 g, yield 61%). 3,5-Dibromo-2-hydroxylpyrazine (21b)Yield: 61%, off-white solid, M.p.: 182-184 C. 1H NMR(400 MHz, CDCl3):delta 11.23 (br, 1H), 7.53 (s, 1H). 1HNMR (400 MHz, DMSO-d6): delta 13.16 (s, 1H), 7.94 (s, 1H).13C NMR (125 MHz, CD3OD): delta 154.19, 136.73, 131.57, 114.62. ESI-MS m/z: 250.9 [M – H]-.
The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.