Cesium carbonate → 2-[2-Chloro-5-(4-ethoxycarbonyl-piperidin-1-yl)-phenyl]-5-fluoro benzoimidazole-1-carboxylic acid tert-butyl ester

HRID 77074Notes

Reaction equation

HRID 77074 reaction equation
[C:1]([O:5][C:6]([N:8]1[C:12]2[CH:13]=[CH:14][C:15]([F:17])=[CH:16][C:11]=2[N:10]=[C:9]1[C:18]1[CH:23]=[C:22](Br)[CH:21]=[CH:20][C:19]=1[Cl:25])=[O:7])([CH3:4])([CH3:3])[CH3:2].[CH2:26]([O:28][C:29]([CH:31]1[CH2:36][CH2:35][NH:34][CH2:33][CH2:32]1)=[O:30])[CH3:27].C(=O)([O-])[O-].[Cs+].[Cs+].C1C=CC(P(C2C(C3C(P(C4C=CC=CC=4)C4C=CC=CC=4)=CC=C4C=3C=CC=C4)=C3C(C=CC=C3)=CC=2)C2C=CC=CC=2)=CC=1>C([O-])(=O)C.[Pd+2].C([O-])(=O)C.C1(C)C=CC=CC=1>[C:1]([O:5][C:6]([N:8]1[C:12]2[CH:13]=[CH:14][C:15]([F:17])=[CH:16][C:11]=2[N:10]=[C:9]1[C:18]1[CH:23]=[C:22]([N:34]2[CH2:35][CH2:36][CH:31]([C:29]([O:28][CH2:26][CH3:27])=[O:30])[CH2:32][CH2:33]2)[CH:21]=[CH:20][C:19]=1[Cl:25])=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

7

Reactant 4

HCID 10796Cesium carbonateHCID 70770Ethyl 4-piperidinecarboxylateHCID 634876Binap, (A+-)-HCID 669779322-(5-Bromo-2-chloro-phenyl)-5-fluoro-benzoimidazole-1-carboxylic acid tert-butyl ester

Product 1

HCID 669774172-[2-Chloro-5-(4-ethoxycarbonyl-piperidin-1-yl)-phenyl]-5-fluoro benzoimidazole-1-carboxylic acid tert-butyl esterYield 68%

Reagents, catalysts & solvents 2

HCID 167845palladium(II) acetateCatalystHCID 1140TolueneSolvent

Conditions

Temperature
80 °C

Procedure

Method 3,4—Step d 2-(5-Bromo-2-chloro-phenyl)-5-fluoro-benzoimidazole-1-carboxylic acid tert-butyl ester (1.04 g, 2.46 mmol), piperidine-4-carboxylic acid ethyl ester (0.49 mL, 3.19 mmol) and cesium carbonate (3.99 g, 12.29 mmol) were placed into a dry Schlenk tube under nitrogen. At the same time palladium acetate (0.11 g, 0.49 mmol), and BINAP (0.46 g, 0.74 mmol) were placed into a dry 7 mL vial under nitrogen. Then dry toluene (4 mL) was added and the mixture was stirred 20 minutes under nitrogen before being added to the first flask. The reaction mixture was heated at 80° C. overnight, cooled to room temperature, salts were filtered off, the organic solution was concentrated under reduced pressure and crude was purified by flash chromatography (eluent: cyclohexane:AcOEt gradient from cyclohexane:AcOEt/5:1 to 1:2) to afford 0.84 g of the title compound (68%).

Workup

  1. additionbefore being added to the first flask
  2. temperaturecooled to room temperature
  3. filtrationsalts were filtered off
  4. concentrationthe organic solution was concentrated under reduced pressure and crude
  5. customwas purified by flash chromatography (eluent: cyclohexane:AcOEt gradient from cyclohexane:AcOEt/5:1 to 1:2)

Sources & evidence

ORD record
ord-8626708b0d0c4a58b20cbe8cb8fb5817
Source dataset
uspto-grants-2014_09
Patent number
US08835648B2

Reaction notes

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