反应详情

温度

0 °C

2-Chloro-5-fluoro-4-methoxyaniline (14.0 g, 79.7 mmol) was cooled to 0° C. and conc. HCl (40 mL) was added over 20 min. The suspension was heated to 55° C. until the aniline was completely dissolved, then cooled back to 0° C. A solution of sodium nitrite (6.1 g, 87.7 mmol) in water (15 mL) was added dropwise over 15 min. After complete addition the mixture was stirred at 0° C. for 30 min. Hexanes (24 mL) and dichloromethane (24 mL) were added followed by a solution of potassium iodide (26.5 g, 159.4 mmol) in water (25 mL) which was added dropwise over 30 min. After stirring at 0° C. for 4 h dichloromethane (50 mL) was added and the reaction quenched with sat. aq. NaHSO3. The solution was extracted with dichloromethane. The organic layers were washed with brine, dried (Na2SO4), filtered and concentrated in vacuo to give 21 g (92%) of 1-chloro-4-fluoro-2-iodo-5-methoxy-benzene: Crude 1H NMR (400 MHz, CDCl3): δ 7.48 (d, J=10.3 Hz, 1H), 7.04 (d, J=7.8 Hz, 1H), 3.86 (s, 3H). The crude material was pure enough to carry on to the next step.

1. dissolutionwas completely dissolved
2. additionAfter complete addition the mixture
3. additionwas added dropwise over 30 min
4. additionwas added
5. customthe reaction quenched with sat. aq. NaHSO3
6. extractionThe solution was extracted with dichloromethane
7. washThe organic layers were washed with brine
8. dry with materialdried (Na2SO4)
9. filtrationfiltered
10. concentrationconcentrated in vacuo