反応 #52991

反応方程式

4-Amino-2,6-dichlorobenzoic acid methyl ester

NaNO2

water

→

2,6-dichloro-4-hydroxybenzoic acid methyl ester

収率 54.8%

溶媒

HCl

反応条件

後処理

1. 1
   workup.STIRRINGthe mixture was stirred for 30 min at that temperature
2. 2
   workup.ADDITIONadded
3. 3
   温度The mixture was then refluxed for 2 h
4. 4
   温度to cool to room temperature
5. 5
   抽出extracted with AcOEt
6. 6
   乾燥dried (MgSO4)
7. 7
   ろ過filtered
8. 8
   その他evaporated
9. 9
   その他The residue was purified by preparative TLC (silica gel; eluent: CH2Cl2)

実験手順

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).

出典