Methanol → Methyl pyrazinoate

A solution of pyrazine-2-carboxylic acid (Aldrich, 12.41 g, 0.1 mol) in MeOH (Aldrich, anhydrous, 100 mL) was stirred with H2SO4 (Aldrich, concentrated, 2 mL) at reflux for 6 hours. The reaction mixture was then concentrated and treated with saturated aqueous Na2CO3 solution (20 mL) till pH=8-9. The mixture was extracted with EtOAc (3×100 mL), and the combined extracts were washed with brine (2×20 mL) and dried over MgSO4. The drying agent was removed by filtration. The organic solution was concentrated and dried to give the title compound 1H NMR (300 MHz, CDCl3) δ 4.06 (s, 3H), 8.73 (dd, J=2.4, 1.6 Hz, 1H), 8.79 (d, J=2.4 Hz, 1H), 9.33 (d, J=1.6 Hz, 1H) ppm. MS (DCI/NH3) m/z 139 (M+H)+.

1. temperatureat reflux for 6 hours
2. concentrationThe reaction mixture was then concentrated
3. additiontreated with saturated aqueous Na2CO3 solution (20 mL) till pH=8-9
4. extractionThe mixture was extracted with EtOAc (3×100 mL)
5. washthe combined extracts were washed with brine (2×20 mL)
6. dry with materialdried over MgSO4
7. customThe drying agent was removed by filtration
8. concentrationThe organic solution was concentrated
9. customdried

ORD record

ord-f02349b0c7b8416b9d0827330b7240c7

Source dataset

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08383658B2