Triisopropyl borate → 5-(Pyridin-2-ylmethyl)benzofuran-2-ylboronic acid

HRID 2075203Notes

Reaction equation

HRID 2075203 reaction equation
[O:1]1[C:5]2[CH:6]=[CH:7][C:8]([CH2:10][C:11]3[CH:16]=[CH:15][CH:14]=[CH:13][N:12]=3)=[CH:9][C:4]=2[CH:3]=[CH:2]1.[Li]CCCC.[B:22](OC(C)C)([O:27]C(C)C)[O:23]C(C)C>C1COCC1>[N:12]1[CH:13]=[CH:14][CH:15]=[CH:16][C:11]=1[CH2:10][C:8]1[CH:7]=[CH:6][C:5]2[O:1][C:2]([B:22]([OH:27])[OH:23])=[CH:3][C:4]=2[CH:9]=1

Participants

5

Reactant 3

HCID 21531Triisopropyl borateHCID 584153222-(Benzofuran-5-ylmethyl)pyridineHCID 178418339Butyllithium

Product 1

HCID 584152775-(Pyridin-2-ylmethyl)benzofuran-2-ylboronic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

A solution of 2-(benzofuran-5-ylmethyl)pyridine (66 mg, 315 mmol) in THF (2 mL) was cooled to −78° C. (under argon), treated with 2.5 M n-BuLi (in hexanes, 2.5 equiv, 0.315 mL) and stirred for 2 min, warmed to 0° C. for 30 min, cooled to −78° C., and treated with triisopropyl borate (178 μL, 946 μmol). After 5 min, cooling was removed, the mixture slowly warmed to room temperature and stirred for 2 h. The mixture was diluted with EtOAc, washed with 1× with brine, dried over MgSO4 and evaporated yielding yellow solids used without further purification. MS (ESI) m/z: Calculated: 253.1; Observed: 254.1 (M++1).

Workup

  1. temperaturecooled to −78° C.
  2. waitAfter 5 min
  3. temperaturecooling
  4. customwas removed
  5. temperaturethe mixture slowly warmed to room temperature
  6. stirringstirred for 2 h
  7. additionThe mixture was diluted with EtOAc
  8. washwashed with 1× with brine
  9. dry with materialdried over MgSO4
  10. customevaporated
  11. customyielding yellow solids
  12. customused without further purification

Sources & evidence

ORD record
ord-83569ad7241449c2b6400a864f09a476
Source dataset
uspto-grants-2011_04
Patent number
US07919519B2

Reaction notes

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