反応 #9652

反応方程式

methyl 4-(4-bromophenyl)-2,2-dimethyl-4-oxobutanoate

bis(pinacolato)diboron

potassium acetate

5-chloro-2-nitroanisole

cesium carbonate

→

methyl 4-(3′-methoxy4′-nitro-1,1′-biphenyl-4-yl)-2,2-dimethyl-4-oxobutanoate

収率 48.2%

溶媒

N,N-dimethylformamide

water

反応条件

後処理

1. 1
   その他was degassed
2. 2
   その他by bubbling a flow of argon for 30 minutes
3. 3
   温度After the mixture was cooled to rt
4. 4
   温度the reaction mixture was heated at 80° C. for 16 h
5. 5
   温度The mixture was then cooled to rt
6. 6
   抽出The aqueous layer was extracted with ethyl acetate
7. 7
   乾燥the combined organic phases were dried over anhydrous sodium sulfate
8. 8
   その他Solvent was removed under reduced pressure
9. 9
   その他the residue was purified by flash chromatography (Biotage Flash 40M, 1:3 ethyl acetate/hexane)

実験手順

A suspension of methyl 4-(4-bromophenyl)-2,2-dimethyl-4-oxobutanoate (200 mg, 0.67 mmol), bis(pinacolato)diboron (170 mg, 0.67 mmol), potassium acetate (197 mg, 2.01 mmol), and palladium acetate (5 mg, 0.02 mmol) in N,N-dimethylformamide (4.0 mL) was degassed by bubbling a flow of argon for 30 minutes. The reaction mixture was then heated at 80° C. for 3 h. After the mixture was cooled to rt, 5-chloro-2-nitroanisole (125 mg, 0.67 mmol), tetrakis(triphenyl-phosphine)palladium(0) (23 mg, 0.02 mmol), and cesium carbonate (327 mg, 1.0 mmol) were added and the reaction mixture was heated at 80° C. for 16 h. The mixture was then cooled to rt, and water was added. The aqueous layer was extracted with ethyl acetate and the combined organic phases were dried over anhydrous sodium sulfate. Solvent was removed under reduced pressure and the residue was purified by flash chromatography (Biotage Flash 40M, 1:3 ethyl acetate/hexane) to afford methyl 4-(3′-methoxy4′-nitro-1,1′-biphenyl-4-yl)-2,2-dimethyl-4-oxobutanoate (120 mg, 48%). LC-MS ret. time 3.38 min, m/z 371.8 (MH+); 1H NMR (300 MHz, CDCl3) δ 1.19 (s, 6H), 3.36 (s, 2H), 3.51 (s, 3H), 4.02 (s, 3H), 7.21–7.24 (m, 2H), 7.64–7.69 (m, 2H), 7.93 (d, 1H), 8.00–8.04 (m, 2H).

出典