반응 #471524

반응 방정식

2-(2-Methoxy-5-methyl-3-nitro-phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

2-(2-methoxy-5-methyl-3-nitro-phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

5-bromothiophene-2-carboxylic acid

sodium carbonate

→

5-(3-nitro-2-methoxy-5-methyl-phenyl)thiophene-2-carboxylic acid

수율 73.6%

용매

1,4-dioxane

water

반응 조건

후처리

1. 1
   온도The reaction mixture was heated
2. 2
   온도to reflux for 1 hour
3. 3
   농축The mixture was concentrated under reduced pressure
4. 4
   workup.DISSOLUTIONthe residue was dissolved in water
5. 5
   여과The mixture was filtered
6. 6
   기타to remove tetrakis(triphenylphosphine)palladium
7. 7
   추출the filtrate was extracted with ethyl acetate
8. 8
   기타to form
9. 9
   기타precipitates
10. 10
    workup.DISSOLUTIONThe precipitates were dissolved in ethyl acetate
11. 11
    건조dried over anhydrous magnesium sulfate
12. 12
    여과filtered
13. 13
    기타to remove the drying agent
14. 14
    농축concentrated under reduced pressure

실험 절차

2-(2-Methoxy-5-methyl-3-nitro-phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 24a (4.0 g, 14.5 mmol), 5-bromothiophene-2-carboxylic acid (1.0 g, 4.8 mmol), tetrakis(triphenylphosphine)palladium (0.276 g, 0.24 mmol) and sodium carbonate (1.01 g, 9.6 mmol) were dissolved in 30 mL of 1,4-dioxane and 10 mL of water. The reaction mixture was heated to reflux for 1 hour. The reaction was monitored by TLC until the disappearance of the starting materials. The mixture was concentrated under reduced pressure and the residue was dissolved in water. The mixture was filtered to remove tetrakis(triphenylphosphine)palladium and the filtrate was extracted with ethyl acetate. The aqueous layer was acidified to form precipitates. The precipitates were dissolved in ethyl acetate, dried over anhydrous magnesium sulfate, filtered to remove the drying agent and concentrated under reduced pressure to obtain the title compound 5-(3-nitro-2-methoxy-5-methyl-phenyl)thiophene-2-carboxylic acid 24b (1.03 g, 73.6%) as a yellow solid.

출처