反应详情

To a solution of the ethyl 2-(6-chloro-3-pyridyl)thiazole-4-carboxylate (0.61 g, 2.3 mmol) and MeOH (50 mL) was added solid NaOMe (135 mg, 2.5 mmol) and stirred at RT. After 3 h the ethyl ester transesterified to the methyl ester. NaOMe (1 eq, 135 mg) was added and the mixture was heated to reflux. After 15 h, the ester hydrolyzed to the 2-(6-chloro-3-pyridyl)thiazole carboxylic acid. NaOMe (2 eq) was added and the reaction was heated at reflux for 18 h. The mixture was acidified to pH 5 with concentrated HCl, extracted with EtOAc, washed with H2O and brine; dried (MgSO4) and concentrated in vacuo to give the desired carboxylic acid as a yellow solid. MS m/z: 237.1 (M+H).

1. temperaturethe mixture was heated to reflux
2. temperaturethe reaction was heated
3. temperatureat reflux for 18 h
4. extractionextracted with EtOAc
5. washwashed with H2O and brine
6. dry with materialdried (MgSO4)
7. concentrationconcentrated in vacuo