Boron tribromide → 2,6-Dichloro-4-hydroxybenzoic acid
反応式
[Cl:1][C:2]1[CH:10]=[C:9]([O:11]C)[CH:8]=[C:7]([Cl:13])[C:3]=1[C:4]([OH:6])=[O:5].B(Br)(Br)Br>C(Cl)Cl>[Cl:1][C:2]1[CH:10]=[C:9]([OH:11])[CH:8]=[C:7]([Cl:13])[C:3]=1[C:4]([OH:6])=[O:5]参加物
4
反応条件
- 温度
- -78 °C
実験手順
2,6-Dichloro-4-methoxy-benzoic acid (500 mg, 2.3 mmol) was taken up in CH2Cl2 and cooled to −78° C. BBr3 (6.9 ml of a 1 M solution in CH2Cl2) was added to the solution at −78° C. The solution was warmed to 25° C. and stirred at that temperature for 16 h. The solution was quenched with 3 N NaOH. The aqueous layer was extracted with CH2Cl2. The aqueous layer was cooled (0° C.) and acidified with conc. HCl (pH=1-2). The aqueous layer was extracted with CH2Cl2. The combined organic layers were dried (Na2SO4). Filtration and concentration gave the crude phenol which was used without further purification.