反应详情

温度

0 °C

85% strength phosphoric acid (50 ml) and 65% strength nitric acid (20 ml) were combined at 0° C. 3.12 g (20.0 mmol) of 4-tert-butylthiazol-2-ylamine were added to this solution and a solution of 1.38 g (20 mmol) of NaNO2 in water (10 ml) was subsequently added dropwise at 0° C. in the course of 30 min. The reaction solution was stirred at 0° C. 1 h and then added dropwise to a suspension of 20.0 g of NaBr and 5.8 g of CuBr in water (20 ml) cooled to 0° C. The mixture was stirred until evolution of gas could no longer be observed. Subsequently, the mixture was adjusted to a pH>10 using 50% strength aq. KOH solution and the product was separated off by steam distillation. The distillate was extracted with EE. The organic phase was dried over MgSO4, filtered, and concentrated in vacuo. 3.03 g (13.8 mmol, 69%) of 2-bromo-4-tert-butylthiazole were obtained as a residue.

1. customwere combined at 0° C
2. temperaturecooled to 0° C
3. stirringThe mixture was stirred until evolution of gas
4. customthe product was separated off by steam distillation
5. extractionThe distillate was extracted with EE
6. dry with materialThe organic phase was dried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo