Hydrochloric Acid → 6-Bromo-1H-pyrazolo[4,3-b]pyridine

HRID 2203657Notes

Reaction equation

HRID 2203657 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[N:10](C(=O)C)[N:9]=[CH:8][C:5]2=[N:6][CH:7]=1.[OH-].[Na+].Cl>O1CCCC1.CO.O>[Br:1][C:2]1[CH:3]=[C:4]2[NH:10][N:9]=[CH:8][C:5]2=[N:6][CH:7]=1

Participants

7

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 71128531HCID 71128531, compound

Product 1

HCID 401522596-Bromo-1H-pyrazolo[4,3-b]pyridineYield 86%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 1-(6-bromo-1H-pyrazolo[4,3-b]pyridin-1-yl)ethanone (1.4 g, 5.9 mmol) in tetrahydrofuran (20 mL) and methanol (15 mL) was added a solution of sodium hydroxide (0.71 g, 18 mmol) in water (5 mL) at 27° C. After 5 h, the reaction was neutralized with hydrogen chloride acid (2 mol/L, 10 mL), and the resulting mixture was extracted with ethyl acetate (3×50 mL). The collected organic extracts were concentrated in vacuo. Purification by flash column chromatography (15→30% ethyl acetate in petroleum ether) afforded 6-bromo-1H-pyrazolo[4,3-b]pyridine (1.0 g, 86% yield). 1H NMR (400 MHz, Chloroform-d) δ 10.46 (brs, 1 H), 8.58 (s, 1 H), 8.25 (s, 1 H), 7.98 (s, 1 H).

Workup

  1. extractionthe resulting mixture was extracted with ethyl acetate (3×50 mL)
  2. concentrationThe collected organic extracts were concentrated in vacuo
  3. customPurification by flash column chromatography (15→30% ethyl acetate in petroleum ether)

Sources & evidence

ORD record
ord-83af4b98e8894655bf350b96a51110a7
Source dataset
uspto-grants-2016_06
Patent number
US09365583B2

Reaction notes

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