Diisopropylamine → (2-Methoxypyridin-3-yl)boronic acid

HRID 1869612Notes

Reaction equation

HRID 1869612 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][N:4]=1.C(NC(C)C)(C)C.C[Si](C[Li])(C)C.C([O:25][B:26](OC(C)C)[O:27]C(C)C)(C)C.[OH-].[Na+]>C1COCC1>[CH3:1][O:2][C:3]1[C:8]([B:26]([OH:27])[OH:25])=[CH:7][CH:6]=[CH:5][N:4]=1

Participants

7

Reactant 5

HCID 7912DiisopropylamineHCID 14798Sodium HydroxideHCID 21531Triisopropyl borateHCID 742012-MethoxypyridineHCID 178418939HCID 178418939, compound

Product 1

HCID 2762709(2-Methoxypyridin-3-yl)boronic acidYield 68.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A mixture of 2-methoxypyridine (23.2 g) and diisopropylamine (1.35 mL) in THF (223 mL) was added to (trimethylsilylmethyl)lithium (218 mL, 13.8 weight percent in hexanes) at −20° C. The lithiation was 84% complete after 7 hours. Tri-isopropylborate (40.8 g) was added at −20° C. over 40 minutes. The mixture was stirred overnight at ambient temperature. 5 percent NaOH (aq, 225 mL) was added. The aqueous layer was removed and brought to pH 5 by adding 10% HCl (aq). The resulting white precipitate was isolated by filtration. After drying, 22.23 g of 2-methoxypyridine-3-boronic acid was obtained (68% yield).

Workup

  1. customcomplete after 7 hours
  2. customThe aqueous layer was removed
  3. additionby adding 10% HCl (aq)
  4. customThe resulting white precipitate was isolated by filtration
  5. customAfter drying

Sources & evidence

ORD record
ord-48897687603b4352aab21fdba3dd1d77
Source dataset
uspto-grants-2009_12
Patent number
US07638635B2

Reaction notes

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