Hydrochloric Acid → 3,5-Dibromo-2-methoxypyrazine
Reaktionsgleichung
[Br:1][C:2]1[C:3](N)=[N:4][CH:5]=[C:6]([Br:8])[N:7]=1.Cl.[CH3:11][OH:12]>>[Br:1][C:2]1[C:3]([O:12][CH3:11])=[N:4][CH:5]=[C:6]([Br:8])[N:7]=1Komponenten
4
Reaktionsbedingungen
- Temperatur
- 60 °C
Versuchsvorschrift
A 100 mL round bottom flask was charged with 3,5-dibromopyrazin-2-amine (1.0 g, 4.0 mmol), methanol (10 mL), methanolic HCl (2.5 M, 0.32 mL, 0.80 mmol) and isoamylnitrile (1.6 mL, 12 mmol). The resulting mixture was heated at 60° C. for 2 h. TLC indicated a complete conversion. Work-up: the solvent was evaporated. The residue was re-dissolved in dichloromethane, washed with saturated aqueous NaHCO3 and brine. The organic layer was dried over anhydrous Na2SO4 and concentrated in vacuo. The residue was further purified by flash column chromatography on silica gel with a 1:20 EtOAc/petroleum ether, to afford 0.50 g (47%) of the product as a white crystal. MS m/z: 267 (M+H+).