Hydrochloric Acid → 3,5-Dibromo-2-methoxypyrazine

Temperature

60 °C

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+).

1. customthe solvent was evaporated
2. dissolutionThe residue was re-dissolved in dichloromethane
3. washwashed with saturated aqueous NaHCO3 and brine
4. dry with materialThe organic layer was dried over anhydrous Na2SO4
5. concentrationconcentrated in vacuo
6. customThe residue was further purified by flash column chromatography on silica gel with a 1:20 EtOAc/petroleum ether

ORD record

ord-feb6fb3a8f4e4eaa9502f68cb9f610f1

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08569300B2