反应详情

A mixture of methyl 4-bromo-2-methoxybenzoate (2.66 g, 10.85 mmol), 28% ammonium hydroxide (25 mL, 642 mmol) and ammonium chloride (2.0 g, 37.4 mmol) was stirred at RT for 20 min and then at 50° C. Once the material converted forms to an oil (ca. 20 min), the mixture was cooled to RT and more ammonium hydroxide (25 mL, 642 mmol) and ammonium chloride (2.0 g, 37.4 mmol) were added. Upon completion of addition, the reaction mixture was stirred at RT overnight. After this time, the mixture was heated to reflux in an open flask to drive off the excess ammonia and then cooled to RT. The mixture was neutralized with conc. HCl and then extracted with ethyl acetate. The extract was dried (Na2SO4) and then concentrated to give a residue. The residue was purified by flash chromatography (40 g silica gel cartridge; EtOAc/Hex) to give 4-bromo-2-methoxybenzamide (510 mg, 2.22 mmol, 20% yield) as a white solid.

1. customat 50° C
2. customto an oil (ca. 20 min)
3. temperaturethe mixture was cooled to RT
4. additionUpon completion of addition
5. stirringthe reaction mixture was stirred at RT overnight
6. temperatureAfter this time, the mixture was heated
7. temperatureto reflux in an open flask
8. temperaturecooled to RT
9. extractionextracted with ethyl acetate
10. dry with materialThe extract was dried (Na2SO4)
11. concentrationconcentrated
12. customto give a residue
13. customThe residue was purified by flash chromatography (40 g silica gel cartridge; EtOAc/Hex)