反应详情

5-Bromo-6-chloropicolinic acid (5 g, 21.1 mmol; CAN 959958-25-9) was dissolved in DMSO (100 mL) to give a colorless solution. To this solution potassium hydroxide (4.75 g, 84.6 mmol) was added. The reaction mixture turned into a white suspension which was stirred for 15 min. Then 1,1,1-trifluoropropan-2-ol (2.41 g, 1.92 mL, 21.1 mmol) was added. The mixture was stirred for 1 d at ambient temp., poured onto ice-water/1N HCl (200 mL) and extracted with EtOAc (2×400 mL). The organic layers were washed with ice-water/brine (200 mL), combined and dried over Na2SO4 and concentrated in vacuo to give the title compound (6.9 g, quant.) as orange solid. MS (EI): m/e=312.3 [M−H]−.

1. customto give a colorless solution
2. stirringThe mixture was stirred for 1 d at ambient temp.
3. additionpoured onto ice-water/1N HCl (200 mL)
4. extractionextracted with EtOAc (2×400 mL)
5. washThe organic layers were washed with ice-water/brine (200 mL)
6. dry with materialdried over Na2SO4
7. concentrationconcentrated in vacuo