Application of 24241-18-7, These common heterocyclic compound, 24241-18-7, name is 2-Amino-3,5-dibromopyrazine, 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.
Zn dust (2 g, 30.6 mmol, 3.8 eq. ) and I2 (200 mg, 10percent of Zn) were added to a dry 100 mL two-necked round bottom flask under argon atmosphere. 12 mL of anhydrous THF and 8 mL of dry DMF were successively added using a syringe. The mixture was stirred at RT until the brown color of I2 disappeared. Then benzylbromide(1.5 mL, 12 mmol, 1.5 eq.) was added using a syringe and the reaction mixture was stirred at 85 °C for 3 h. After insertion of Zn, the reaction mixture was cooled to RT and 2-amino-3,5-dibromopyrazine (2g, 8 mmol, 1.0 eq.) and bis(triphenylphosphine)palladium(II) chloride (220 mg, 0.31 mmol , 11 percent of pyrazine) in 18 mL of anhydrous THF and 12 mL of dry DMF were added. The reaction mixture was continuously stirred at RT for 12 h.Then the mixture was filtered by diatomite. The filtrate was poured in 50 mL of water and extracted with ethyl acetate (3*30 mL). The organic fractions were combined and dried over anhydrous sodium sulfate and then concentrated on a rotary evaporator. The resulting residue was purified by silica gel column chromatography using petroleum ether/ethyl acetate (3/1,v/v ), affording 3-benzyl-5-bromopyrazine-2-amine (5) as a yellow viscous oil (1.8 g, 84.9percent). 1H NMR (CDCl3, 300 MHz): delta 4.10 (s, 2H,CH2), 4.60 (br s, 2H, NH2),7.10-7.41 (m, 5H, Ar-H), 8.15 (s, 1H, Ar-H); ESI-MS calcd. for C11H10BrN3: 263.0, found: 264.3 (M+H+).
The synthetic route of 24241-18-7 has been constantly updated, and we look forward to future research findings.
Reference:
Article; Yuan, Ming-Liang; Jiang, Tian-Yu; Du, Lu-Pei; Li, Min-Yong; Chinese Chemical Letters; vol. 27; 4; (2016); p. 550 – 554;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem