A common heterocyclic compound, 873-42-7, name is 2-Amino-3,5-dichloropyrazine, molecular formula is C4H3Cl2N3, 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. 873-42-7.
Into a flask, under an inert atmosphere of nitrogen, was placed 1,1,1,2,2-pentafluoro-4-iodobutane (21.7 g, 79 mmol), zinc metal (8.4 g, 128 mmol) and DMA (60 mL). This was followed by the dropwise addition of a solution of iodine (0.77 g, 3.05 mmol) in DMA (4 mL). The resulting mixture was stirred for 3 h at 80C. The reaction was cooled and directly used in the next step. In a flask, under an inert atmosphere of argon, was added 3,5-dichloropyrazin-2-amine (10.0 g, 61.0 mmol) and Pd(PPh3)2Cl2 (4.3 g, 6.1 mmol). The resulting mixture was allowed to stir for 1 h at RT. The intermediate from Step A (65 mL, 79 mmol) was added and the resulting solution was warmed at 45C for 3 h. The reaction was then quenched by the addition of sat. aq. NH4Cl. The resulting solution was extracted with EtOAc (3X), and the organic layers combined, washed with brine, dried over anhydr. Na2SO4, and filtered. The filtrate was conc. in vacuo to dryness. The residue was purified RP-HPLC with acetonitrile:water (0.2% TFA) to afford the title compound.
The synthetic route of 2-Amino-3,5-dichloropyrazine has been constantly updated, and we look forward to future research findings.
Reference:
Patent; MERCK SHARP & DOHME CORP.; BERGER, Raphaelle; DONG, Guizhen; RAGHAVAN, Subharekha; YANG, Zhiqiang; (179 pag.)WO2017/200857; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem