Hydrochloric Acid → 5-methoxy-1H-pyrrolo[3,2-b]pyridin-6-ylboronic acid

HRID 2378972Notes

Reaction equation

HRID 2378972 reaction equation
[CH3:1][O:2][C:3]1[N:8]=[C:7]2[CH:9]=[CH:10][N:11]([Si](C(C)C)(C(C)C)C(C)C)[C:6]2=[CH:5][C:4]=1[B:22]([OH:25])[O:23]C.Cl>C1COCC1>[CH3:1][O:2][C:3]1[N:8]=[C:7]2[CH:9]=[CH:10][NH:11][C:6]2=[CH:5][C:4]=1[B:22]([OH:25])[OH:23]

Participants

4

Reactant 2

HCID 313Hydrochloric Acid2×HCID 59006331methyl hydrogen 5-methoxy-1-(triisopropylsilyl)-1H-pyrrolo[3,2-b]pyridin-6-ylboronate

Product 1

HCID 590063605-methoxy-1H-pyrrolo[3,2-b]pyridin-6-ylboronic acidYield 98.1%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of methyl hydrogen 5-methoxy-1-(triisopropylsilyl)-1H-pyrrolo [3,2-b]pyridin-6-ylboronate (1.5 g, 4.14 mmol) (from 65236-015) in THF (10 mL) was treated with HCl (4M in 1,4-dioxane) for 1 hr at 0° C., checked with LC/MS: ˜50% conversion, thus additional 1.3 ml HCl (4M in 1,4-dioxane) was added, stirred at rt over night. Most of the solvent was removed on rotary vacuo, and the residue as a white solid was triturated with Et2O (3 ml), filtration and washing with Et2O (2×3 mL) to afford the expected product, 5-methoxy-1H-pyrrolo[3,2-b]pyridin-6-ylboronic acid (0.78 g, 98%) as a white solid. 1H-NMR (500 MHz, MeOD) δ ppm 1.04-1.12 (m, 1 H) 1.18 (d, J=7.32 Hz, 1 H) 4.28-4.33 (m, 4 H) 6.74 (d, J=2.44 Hz, 1 H) 7.89 (d, J=3.05 Hz, 1 H) 8.42 (s, 1 H); Mass spec 193.20 Calc for C8H9BN2O3 192.07.

Workup

  1. customMost of the solvent was removed on rotary vacuo
  2. filtrationthe residue as a white solid was triturated with Et2O (3 ml), filtration
  3. washwashing with Et2O (2×3 mL)

Sources & evidence

ORD record
ord-e3b617651cff4ca9848fac1779ea3e82
Source dataset
uspto-grants-2008_12
Patent number
US07470680B2

Reaction notes

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