反应详情

Heat to reflux a mixture of 5-methyl-thiazole-4-carboxylic acid ethyl ester (4.87 g, 28.5 mmol) and N-bromosuccinimide (5.06 g, 28.5 mmol) in CCl4 (100 mL) by irradiation with a 275 watt tungsten sun lamp. After 3 h, cool to room temperature and filter off a tan solid. Concentrate the filtrate by rotavap to give 6.42 g crude product as an orange oil. Purify on silica gel [115 g, 0-15% (2M NH3/MeOH)/(1:1 CH2Cl2/hexanes)] to give 3.61 g (51%) of the title compound as a yellow solid. LC-ES/MS m/z 250, 252 (M+1), TR=2.0 min (86%). Starting material: m/z 172 (M+1), TR=1.7 min (14%).

1. temperatureHeat
2. temperatureto reflux
3. filtrationfilter off a tan solid
4. concentrationConcentrate the filtrate by rotavap
5. customto give 6.42 g crude product as an orange oil
6. customPurify on silica gel [115 g, 0-15% (2M NH3/MeOH)/(1:1 CH2Cl2/hexanes)]