反应 #347109

反应方程式

HCl

Sodium nitrate

4-bromo-3-hydroxy-6-methoxybenzoic acid

→

title compound

4-Bromo-3-hydroxy-6-methoxy-2-nitrobenzoic acid

溶剂

water

diethyl ether

反应条件

后处理

1. 1
   温度After slowly raising the temperature to room temperature the mixture
2. 2
   萃取Extraction between H2O (20 mL) and CH2Cl2 (3×30 mL)
3. 3
   其他drying the organic phase
4. 4
   过滤with MgSO4, filtration and evaporation under reduced pressure
5. 5
   其他gave
6. 6
   workup.ADDITIONa mixture of products
7. 7
   其他Purification by silica gel chromatography (HOAc-EtOAc-toluene 1:2:8)

实验过程

Sodium nitrate (361 mg, 4.25 mmol) was dissolved in water (4 mL) and LaNO3 *6H2O (18 mg, 0.04 mmol) and HCl (12M, 4 mL) were added. The solution was cooled to 0° C. and a slurry of 4-bromo-3-hydroxy-6-methoxybenzoic acid in diethyl ether (20 mL) was added to the reaction mixture in portions during 10 min. After slowly raising the temperature to room temperature the mixture was stirred for 7 h. Extraction between H2O (20 mL) and CH2Cl2 (3×30 mL), drying the organic phase with MgSO4, filtration and evaporation under reduced pressure gave a mixture of products. Purification by silica gel chromatography (HOAc-EtOAc-toluene 1:2:8) gave the title compound (0.6 g). 1H NMR (CD3OD): δ7.57 (s, 1H), 3.85 (s, 3H). MS (EI, 70 eV): m/z (rel. int.) 291/293 (M+, 21/19).

来源