反应详情

Hexamethylenetetramine (14.7 g, 105 mmol) was slowly added to a solution of 2-bromo-4-fluoro-phenol (10 g, 52.4 mmol) in trifluoroacetic acid (40 ml) at rt and heated to reflux for 18 h. The reaction mixture was cooled to rt and then water (60 ml) and sulfuric acid (30 ml, 50%) were added. The mixture was stirred for 3 h at rt and then extracted twice with ethyl acetate. The combined organic extracts were washed with 1N HCl, water, dried (Na2SO4), filtered and concentrated under reduced pressure to give 9.5 g (83%) of 3-bromo-5-fluoro-2-hydroxy-benzaldehyde.

1. temperatureheated
2. temperatureto reflux for 18 h
3. extractionextracted twice with ethyl acetate
4. washThe combined organic extracts were washed with 1N HCl, water
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure