Methanol → Quinoxaline-6-carboxylic acid

To a solution of methyl quinoxaline-6-carboxylate (500 mg, 2.66 mmol) in 10 mL of THF was added sodium hydroxide (5N, 2.5 mL, 12.5 mmol) followed by methanol (2.5 mL). The reaction was stirred at room temperature overnight and then concentrated in vacuo to remove THF/MeOH. The resulting aqueous mixture was acidified with 1N HCl until the pH was slightly acidic (pH=5). The resulting solution was extracted with EtOAc (3×), and the combined organic layers were then washed with brine, dried over anhydrous MgSO4, filtered and concentrated in vacuo. The resulting white solid was used without further purification. LC-MS: 3.50 min. (M+H)=175.16.

1. concentrationconcentrated in vacuo
2. customto remove THF/MeOH
3. extractionThe resulting solution was extracted with EtOAc (3×)
4. washthe combined organic layers were then washed with brine
5. dry with materialdried over anhydrous MgSO4
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customThe resulting white solid was used without further purification
9. custom3.50 min. (M+H)=175.16

ORD record

ord-6568c7a2e8af427090b3339e0c3ef933

Source dataset

uspto-grants-2009_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07625938B2