Potassium Carbonate → 2-Pyrazinecarboxylic acid, 5-(difluoromethoxy)-, methyl ester

Temperature

100 °C

To 5-hydroxypyrazine-2-carboxylic acid methyl ester (2.0 g, 13 mmol) in a glass tube reaction vessel in DMF (26 mL) was added potassium carbonate (5.3 g, 39 mmol) and sodium 2-chloro-2,2-difluoroacetate (4.0 g, 26 mmol). The reaction vessel was capped and warmed to 100° C. The reaction was stirred for 30 minutes and cooled to room temperature. The reaction was filtered washing with EtOAc. The filtrate was concentrated in vacuo. The residue was taken up into EtOAc and washed with brine. The organic layer was dried (MgSO4), filtered, and concentrated in vacuo. The residue was purified by silica gel chromatography (0-40% EtOAc/hex) to give methyl-5-(difluoromethoxy)pyrazine-2-carboxylate (0.09 g, 0.46 mmol) (0.40 g, 20%).

1. customThe reaction vessel was capped
2. temperaturecooled to room temperature
3. filtrationThe reaction was filtered
4. washwashing with EtOAc
5. concentrationThe filtrate was concentrated in vacuo
6. washwashed with brine
7. dry with materialThe organic layer was dried (MgSO4)
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customThe residue was purified by silica gel chromatography (0-40% EtOAc/hex)

ORD record

ord-66d47338b9954add9807be48842679e4

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09428475B2