Sodium Hydroxide → 5-Methoxy-3-methylpyrazine-2-carboxylic acid

Temperature

40 °C

To a solution of methyl 5-methoxy-3-methylpyrazine-2-carboxylate (5.1 g, 28.0 mmol) in MeOH (50 mL) was added sodium hydroxide 1.0 N solution (30.8 mL, 30.8 mmol). The reaction was heated to 40° C. for 2 h. The reaction mixture was concentrated, diluted with water and pH adjusted to 4. The solid that precipitated was filtered and dried. The remaining acidic solution was extracted with EtOAc and DCM. The combined organics were dried with Na2SO4, and concentrated in vacuo to give another batch of solid. The solids were combined and dried to give 5-methoxy-3-methylpyrazine-2-carboxylic acid (4.5 g, 96% yield). 1H NMR (300 MHz, DMSO-d6) δ 13.00 (br. s., 1H), 8.18 (s, 1H), 3.96 (s, 3H), 2.67 (s, 3H).

1. concentrationThe reaction mixture was concentrated
2. additiondiluted with water
3. customThe solid that precipitated
4. filtrationwas filtered
5. customdried
6. extractionThe remaining acidic solution was extracted with EtOAc and DCM
7. dry with materialThe combined organics were dried with Na2SO4
8. concentrationconcentrated in vacuo
9. customto give another batch of solid
10. customdried

ORD record

ord-650eb4ba98ce4548a29eb49cdb106b27

Source dataset

uspto-grants-2016_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09309263B2