Cesium carbonate → HCID 86694689, compound

HRID 475093Notes

Reaction equation

HRID 475093 reaction equation
Br[C:2]1[CH:16]=[CH:15][C:5]2[N:6]([CH:9]3[CH2:14][CH2:13][CH2:12][CH2:11][O:10]3)[CH:7]=[N:8][C:4]=2[C:3]=1[O:17][CH3:18].[CH:19](/B(O)O)=[CH:20]\[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1.C([O-])([O-])=O.[Cs+].[Cs+]>O1CCOCC1.O>[CH3:18][O:17][C:3]1[C:4]2[N:8]=[CH:7][N:6]([CH:9]3[CH2:14][CH2:13][CH2:12][CH2:11][O:10]3)[C:5]=2[CH:15]=[CH:16][C:2]=1[CH:19]=[CH:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1

Participants

6

Reactant 3

HCID 10796Cesium carbonateHCID 5702628Styrylboronic acidHCID 71272697HCID 71272697, compound

Product 1

HCID 86694689HCID 86694689, compoundYield 77.9%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Conditions

Temperature
100 °C

Procedure

A 1 L three-necked round bottom flask fitted with an overhead stirrer was dried and cooled under a stream of nitrogen then charged with 5-bromo-4-methoxy-1-(tetrahydro-pyran-2-yl)-1H-benzoimidazole (30 g, 0.096 mol, 1.0 equiv.) in 1,4-dioxane (300 mL) and water (60 mL). The mixture was degassed with nitrogen. To the degassed solution at RT was added sequentially trans-β-styrene boronic acid (14.26 g, 0.096 mol, 1.0 equiv.), Cs2CO3 (62.82 g, 0.19 mol, 2.0 equiv.), Pd(II)Cl2(PPh3)2 (3.38 g, 0.004 mol, 0.05 equiv.) then the reaction was heated with stirring at 100° C. for 6 h. The reaction mixture was quenched with ice cold water (1 L) and extracted with EtOAc (2×1 L). The organic layers were combined, washed with brine solution (500 mL), dried (Na2SO4), filtered and concentrated in vacuo. The crude material was purified by SiO2 chromatography eluting with an EtOAc/hexane gradient (40-50% EtOAc) to afford 4-methoxy-5-styryl-1-(tetrahydro-pyran-2-yl)-1H-benzoimidazole (25 g, 77%) as a brown solid.

Workup

  1. customA 1 L three-necked round bottom flask fitted with an overhead stirrer
  2. customwas dried
  3. temperaturecooled under a stream of nitrogen
  4. customThe mixture was degassed with nitrogen
  5. temperaturethe reaction was heated
  6. customThe reaction mixture was quenched with ice cold water (1 L)
  7. extractionextracted with EtOAc (2×1 L)
  8. washwashed with brine solution (500 mL)
  9. dry with materialdried (Na2SO4)
  10. filtrationfiltered
  11. concentrationconcentrated in vacuo
  12. customThe crude material was purified by SiO2 chromatography
  13. washeluting with an EtOAc/hexane gradient (40-50% EtOAc)

Sources & evidence

ORD record
ord-464c9952a5d74160a8dbaf377348bc54
Source dataset
uspto-grants-2014_01
Patent number
US08637537B2

Reaction notes

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