Reaktion #164263

Reaktionsgleichung

2-(5-Bromo-2-fluoro-phenyl)-5-methyl-benzoimidazole-1-carboxylic acid tert-butyl ester

piperidine-4-carboxylic acid ethyl ester

cesium carbonate

BINAP

→

title compound

Ausbeute 99.5%

2-[5-(4-Ethoxycarbonyl-piperidin-1-yl)-2-fluoro-phenyl]-5-methyl-benzoimidazole-1-carboxylic acid tert-butyl ester

Ausbeute 99.5%

Lösungsmittel

water

toluene

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONthe mixture was added to the first schlenk
2. 2
   Filtrationthe organic layer was filtered over Na2SO4
3. 3
   Sonstigepurified by flash chromatography (eluent: cyclohexane:EtOAc 8:2)

Vorschrift

Method 8—Step a 2-(5-Bromo-2-fluoro-phenyl)-5-methyl-benzoimidazole-1-carboxylic acid tert-butyl ester (obtained as described in general method 6, step c) (0.94 g, 2.40 mmol), piperidine-4-carboxylic acid ethyl ester (0.48 g, 3.12 mmol) and cesium carbonate (3.90 g, 12.01 mmol) were placed into a dried schlenk tube and 3 cycles of vacuum/nitrogen were performed, then dry toluene (4 mL) was added. At the same time palladium(II)acetate (0.82 g, 0.36 mmol), and BINAP (0.45 g, 0.72 mmol) were placed into a dried schlenk tube under nitrogen and 3 cycles of vacuum/nitrogen were performed. Then dry toluene (2 mL) was added, at room temperature under nitrogen, and the mixture was added to the first schlenk. The reaction mixture was heated at 80° C. overnight, water (5 mL) was added, the organic layer was filtered over Na2SO4 and then purified by flash chromatography (eluent: cyclohexane:EtOAc 8:2) to obtain 1.15 g of the title compound in quantitative yield.

Quelle