Hydrochloric Acid → 2-(6-Methoxy-3-pyridinyl)-1,3-thiazole-4-carboxylic acid

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Reaction Steps

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).

Provenance & Evidence