反应详情

温度

2.5 °C

4-Amino-2,6-dichlorobenzoic acid methyl ester (0.5 g) was suspended in 20% HCl (25 mL) and stirred for 30 min then cooled to 0-5° C. After slow addition of NaNO2 (188 mg), the mixture was stirred for 30 min at that temperature and added to boiling water (50 mL). The mixture was then refluxed for 2 h, allowed to cool to room temperature and extracted with AcOEt, dried (MgSO4), filtered and evaporated. The residue was purified by preparative TLC (silica gel; eluent: CH2Cl2) to give 2,6-dichloro-4-hydroxybenzoic acid methyl ester (275 mg).

1. stirringthe mixture was stirred for 30 min at that temperature
2. additionadded
3. temperatureThe mixture was then refluxed for 2 h
4. temperatureto cool to room temperature
5. extractionextracted with AcOEt
6. dry with materialdried (MgSO4)
7. filtrationfiltered
8. customevaporated
9. customThe residue was purified by preparative TLC (silica gel; eluent: CH2Cl2)