反应详情

To a mixture of 4-[(dimethyl-carbamoyl)sulfanyl]-2-methyl-thiazole-5-carboxylic acid ethyl ester (0.84 g, 3.06 mmol) in MeOH (30 ml) is added sodium hydride (60% oil dispersion) (0.4 g, 10.1 mmol). The mixture is refluxed for 1 h under an atmosphere of nitrogen and concentrated. The residue is treated with 1M hydrochloric acid and extracted with EtOAc (3×30 ml). The combined organic layers are washed with brine (30 ml), dried over sodium sulfate and concentrated to give 4-mercapto-2-methyl-thiazole-5-carboxylic acid ethyl ester (0.58 g, 2.83 mmol, 94%), which is used in the next step without further purification.

1. temperatureThe mixture is refluxed for 1 h under an atmosphere of nitrogen
2. concentrationconcentrated
3. additionThe residue is treated with 1M hydrochloric acid
4. extractionextracted with EtOAc (3×30 ml)
5. washThe combined organic layers are washed with brine (30 ml)
6. dry with materialdried over sodium sulfate
7. concentrationconcentrated