反应详情

To a solution of 3-bromo-5-nitro-phenol (16.9 g, 77.52 mmol, commercially available [CAS 116632-23-6 {Specs}]) in ethanol (300 ml) and water (100 ml) was added solid ammonium chloride (16.59 g, 310 mmol) and then powdered electrolytic iron (34.4 g, 698 mmol). The material was heated from ambient to reflux temperature (oil bath). The material was refluxed for 3 hours and then filtered, hot, through a plug of celite, washing well with several volumes of hot EtOAc. The solvent was stripped and the remainder was taken up in EtOAc (150 ml) and water (150 ml) and the material shaken. The organic phase was collected and washed with brine (150 ml). The aqueous phases were back extracted with EtOAc (2×100 ml). The organics were combined, dried (MgSO4), filtered and stripped to provide a crude oil. The material was adsorbed onto silica (50 g) and purified by silica gel chromatography, eluting with 15% to 50% ethyl acetate in hexanes to afford 10.35 g of 3-amino-5-bromo-phenol as a dark golden-brown viscous oil.

1. temperatureThe material was heated from ambient
2. temperatureto reflux temperature (oil bath)
3. temperatureThe material was refluxed for 3 hours
4. filtrationfiltered
5. washhot, through a plug of celite, washing well with several volumes of hot EtOAc
6. customThe organic phase was collected
7. washwashed with brine (150 ml)
8. extractionThe aqueous phases were back extracted with EtOAc (2×100 ml)
9. dry with materialdried (MgSO4)
10. filtrationfiltered
11. customto provide a crude oil
12. custompurified by silica gel chromatography
13. washeluting with 15% to 50% ethyl acetate in hexanes