反应详情

A solution of 2-bromo-6-ethylphenol 1 (3.8 g, 18.8 mmol) hexamethylene tetraamine (10.6 g, 75.4 mmol), and acetic acid (120 mL) was heated at reflux for 12 h. Most of the solvent was removed under reduced pressure, and the residue was poured into water (500 nL), and extracted with ethyl acetate (3×100 mL). The combined organic layers were washed with saturated aqueous NaHCO3 until gas evolution ceased. The organic layer was washed with brine (1×100 mL), dried (Na2SO4), filtered, and concentrated. The residue was purified by silica gel chromatography (SiO2, gradient elution 5 to 10% ethyl acetate/hexanes) to yield 2.0 g (46%) of 3-bromo-5-ethyl-4-hydroxybenzaldehyde 2 as a colorless solid.

1. temperatureat reflux for 12 h
2. customMost of the solvent was removed under reduced pressure
3. additionthe residue was poured into water (500 nL)
4. extractionextracted with ethyl acetate (3×100 mL)
5. washThe combined organic layers were washed with saturated aqueous NaHCO3 until gas evolution
6. washThe organic layer was washed with brine (1×100 mL)
7. dry with materialdried (Na2SO4)
8. filtrationfiltered
9. concentrationconcentrated
10. customThe residue was purified by silica gel chromatography (SiO2, gradient elution 5 to 10% ethyl acetate/hexanes)