Reaktion #163236

Reaktionsgleichung

{4-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl]-cyclohexyl}-acetic acid methyl ester

2,5-dibromopyridine

Na2CO3

→

title compound

{4-[4-(5-Bromo-pyridin-2-yl)-phenyl]-cyclohexyl}-acetic acid methyl ester

Lösungsmittel

toluene ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe biphasic mixture was sparged with nitrogen for 10 min
2. 2
   TemperaturThe reaction was cooled to room temperature
3. 3
   Sonstigepartitioned between ethyl acetate and saturated ammonium chloride solution
4. 4
   WaschenThe organic extracts were washed with brine
5. 5
   Trocknendried over sodium sulphate
6. 6
   Einengenconcentrated in vacuo
7. 7
   SonstigePurification by silica gel chromatography (7-40% EtOAc in hexanes)

Vorschrift

To a solution of {4-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl]-cyclohexyl}-acetic acid methyl ester (4.0 g, 11.2 mmol, 1.0 equiv) and 2,5-dibromopyridine (3.2 g, 13.4 mmol, 1.2 equiv) in 50 Ml toluene/ethanol (1:1) was added 2 M Na2CO3 (16.8 Ml, 3 equiv) followed by Pd(PPh3)4 (0.38 g, 0.34 mmol, 0.03 equiv). The biphasic mixture was sparged with nitrogen for 10 min, then heated to 60° C. for 3 days. The reaction was cooled to room temperature and then partitioned between ethyl acetate and saturated ammonium chloride solution. The organic extracts were washed with brine, then dried over sodium sulphate and concentrated in vacuo. Purification by silica gel chromatography (7-40% EtOAc in hexanes) afforded the title compound as a yellow solid: 1H NMR (400 MHz, CDCl3) δ 1.11 (dd, J=13.01, 2.15 Hz, 2H) 1.41-1.54 (m, 2H) 1.76-1.90 (m, 5H) 2.20 (d, J=6.57 Hz, 2H) 2.46 (tt, J=12.09, 3.19 Hz, 1H) 3.62 (s, 3H) 7.23 (d, J=8.08 Hz, 2H) 7.53 (dd, J=8.59, 0.76 Hz, 1H) 7.77 (dd, J=8.46, 2.40 Hz, 1H) 7.81 (q, J=3.87 Hz, 1H) 7.81 (d, J=8.34 Hz, 1H) 8.64 (d, J=1.77 Hz, 1H); (M+H)+390.0.

Quelle