反应详情

To a suspension of 2-tert-butoxycarbonylamino-thiazole-4-carboxylic acid (prepared as described in example 15) (183 mg, 0.75 mmol) in toluene (7 mL) was added thionyl chloride (2.2 mL, 30 mmol) and the mixture heated to reflux under argon for 2.5 hours. The mixture was then concentrated in vacuo, the residue suspended in dichloromethane (7 mL), a 2 M solution of dimethylamine in tetrahydrofuran (0.5 mL, 1 mmol) added and the mixture stirred at ambient temperature under argon overnight. The reaction mixture was concentrated in vacuo, the residue suspended in ethyl acetate and the solid removed by filtration. The filtrate was concentrated in vacuo and the residue purified by chromatography over silica gel eluted with 1% v/v methanol in ethyl acetate to give (4-dimethylcarbamoyl-thiazol-2-yl)-carbamic acid tert-butyl ester as a colorless solid (152 mg, 75%).

1. temperaturethe mixture heated
2. temperatureto reflux under argon for 2.5 hours
3. concentrationThe mixture was then concentrated in vacuo
4. concentrationThe reaction mixture was concentrated in vacuo
5. customthe solid removed by filtration
6. concentrationThe filtrate was concentrated in vacuo
7. customthe residue purified by chromatography over silica gel
8. washeluted with 1% v/v methanol in ethyl acetate