반응 #347109

반응 방정식

HCl

Sodium nitrate

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

→

title compound

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

용매

water

diethyl ether

반응 조건

후처리

1. 1
   온도After slowly raising the temperature to room temperature the mixture
2. 2
   추출Extraction between H2O (20 mL) and CH2Cl2 (3×30 mL)
3. 3
   기타drying the organic phase
4. 4
   여과with MgSO4, filtration and evaporation under reduced pressure
5. 5
   기타gave
6. 6
   workup.ADDITIONa mixture of products
7. 7
   기타Purification by silica gel chromatography (HOAc-EtOAc-toluene 1:2:8)

실험 절차

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).

출처