4-Benzyloxy-phenylboronic acid → HCID 178493142, compound

HRID 722043Notes

Reaction equation

HRID 722043 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][N:6]=[C:5]([CH2:9][CH2:10][C:11]2[NH:20][C:14]3=[N:15][CH:16]=[C:17](I)[CH:18]=[C:13]3[N:12]=2)[CH:4]=1.[CH2:21]([O:28][C:29]1[CH:34]=[CH:33][C:32](B(O)O)=[CH:31][CH:30]=1)[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1>>[CH3:1][O:2][C:3]1[CH:8]=[CH:7][N:6]=[C:5]([CH2:9][CH2:10][C:11]2[NH:20][C:14]3=[N:15][CH:16]=[C:17]([C:32]4[CH:33]=[CH:34][C:29]([O:28][CH2:21][C:22]5[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=5)=[CH:30][CH:31]=4)[CH:18]=[C:13]3[N:12]=2)[CH:4]=1

Participants

3

Reactant 2

HCID 27343144-Benzyloxy-phenylboronic acidHCID 178493175HCID 178493175, compound

Product 1

HCID 178493142HCID 178493142, compoundYield 64.2%

Procedure

0.38 g of 2-[2-(4-methoxypyridin-2-yl)ethyl]-6-iodo-3H-imidazo[4,5-b]pyridine (example 7) and 0.342 g of 4-benzyloxyphenylboronic acid are dissolved in 16 ml degassed dioxane. Then a solution of 0.276 g of potassium carbonate and 0.85 g of lithium chloride in 13 ml of degassed water and 0.115 g of tetrakis(triphenylphosphine)palladium(0) are added. The mixture is heated to reflux under N2 for 20 hours and, after cooling, addition of water and adjusting the pH to 7, it is extracted three times with dichloromethane. The combined organic phases are dried over sodium sulfate, concentrated and the residue is chromatographed on a silica gel column (dichloromethane/methanol 30–26:1). Concentration of the chromatographically pure fractions and crystallisation from ethyl acetate gives 0.28 g of the title compound as a colourless solid of m.p. 161–162° C. The mass spectrum shows the molecular peaks MH+ and 2MNa+ at 437.3 and 894.2 Da.

Workup

  1. customdegassed dioxane
  2. additionThen a solution of 0.276 g of potassium carbonate and 0.85 g of lithium chloride in 13 ml of degassed water and 0.115 g of tetrakis(triphenylphosphine)palladium(0) are added
  3. temperatureThe mixture is heated
  4. temperatureto reflux under N2 for 20 hours
  5. temperatureafter cooling
  6. additionaddition of water
  7. extractionis extracted three times with dichloromethane
  8. dry with materialThe combined organic phases are dried over sodium sulfate
  9. concentrationconcentrated
  10. customthe residue is chromatographed on a silica gel column (dichloromethane/methanol 30–26:1)
  11. customConcentration of the chromatographically pure fractions and crystallisation from ethyl acetate

Sources & evidence

ORD record
ord-474fd7c9283e40be9c2819417eb39bc0
Source dataset
uspto-grants-2006_11
Patent number
US07138399B2

Reaction notes

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