反应详情

The product from Step 1 (935 mg, 4.11 mmol) was taken up in CHCl3 (20 mL) and placed in a cool water bath. NaHCO3 (380 mg, 4.52 mmol) was added, followed by bromine (1.315 g, 8.23 mmol). After stirring for 2 h at room temperature, some starting material remained, so additional NaHCO3 (380 mg, 4.52 mmol) and bromine (1.315 g, 8.23 mmol) were added. After another 2 h at room temperature, the reaction was diluted with aqueous 10% Na2S2O3 and aqueous saturated NaHCO3 and extracted with CH2Cl2 (2×). The combined organic layers were washed with brine, dried (Na2SO4), and evaporated. Flash chromatography (0-10% ethyl acetate in hexanes) afforded tert-butyl 2-(5-bromo-1,3-thiazol-2-yl)-2-methylpropanoate (1.032 g, 82%) as a colorless oil. MS ESI: [M-t-Bu]+ m/z 249.9/251.9.

1. customplaced in a cool water bath
2. waitAfter another 2 h at room temperature
3. extractionextracted with CH2Cl2 (2×)
4. washThe combined organic layers were washed with brine
5. dry with materialdried (Na2SO4)
6. customevaporated