反应详情

A solution of 2-methyl-thiazole-4-carboxylic acid (2.48 g, 17.32 mmol) in tetrahydrofurane (200.00 ml) was cooled to −78° C. under argon and treated with a 1.6N solution of buthyllithium in hexanes (22.74 ml, 36.38 mmol). The reaction mixture was left to warm to room temperature over 15 min, then cooled again to −78° C. A solution of elemental bromine (3.04 g, 19.05 mmol) in hexane (2.00 ml) was added. The reaction mixture was left to warm to room temperature, then quenched by addition of 1N HCl. The mixture was extracted three times with methylene chloride, and the combined organic layers were dried over sodium sulphate and evaporated. 5-Bromo-2-methyl-thiazole-4-carboxylic acid (3.79 g, 99%) was obtained as a yellow solid, MS (ISP): m/e=220.0, 222.1 (M−H), which was used crude.

1. waitThe reaction mixture was left
2. temperaturecooled again to −78° C
3. waitThe reaction mixture was left
4. temperatureto warm to room temperature
5. customquenched by addition of 1N HCl
6. extractionThe mixture was extracted three times with methylene chloride
7. dry with materialthe combined organic layers were dried over sodium sulphate
8. customevaporated