2-Bromopropanedial → 5-Bromopyrazolo[3,4-b]pyridine

HRID 1787578Notes

Reaction equation

HRID 1787578 reaction equation
[Br:1][CH:2]([CH:5]=O)[CH:3]=O.[NH2:7][C:8]1[CH:12]=[CH:11][NH:10][N:9]=1>C(O)(=O)C>[Br:1][C:2]1[CH:5]=[C:12]2[CH:11]=[N:10][NH:9][C:8]2=[N:7][CH:3]=1

Participants

4

Reactant 2

HCID 749452-BromopropanedialHCID 178418806HCID 178418806, compound

Product 1

HCID 404274545-Bromopyrazolo[3,4-b]pyridineYield 11.2%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Dissolve 2-bromomalonaldehyde (Aldrich; 2.5 g, 16.5 mmol) and 3-aminopyrazole (Aldrich; 1.38 g, 16.5 mmol) in glacial acetic acid (25 mL) and reflux under nitrogen for 2 h. Concentrate under reduced pressure and dissolve the residue in absolute methanol (150 mL), vacuum filter through a pad of diatomaceous earth and concentrate under reduced pressure. Purify via chromatography (silica gel, hexane to 50% ethyl acetate/50% hexane) to obtain 365 mg (11%) of the title compound as a light yellow solid. TOF MS ES+ exact mass calculated for C6H5N3Br (p+H): m/z=197.9667, Found: 197.9674.

Workup

  1. temperaturereflux under nitrogen for 2 h
  2. concentrationConcentrate under reduced pressure
  3. dissolutiondissolve the residue in absolute methanol (150 mL)
  4. filtrationvacuum filter through a pad of diatomaceous earth
  5. concentrationconcentrate under reduced pressure
  6. customPurify via chromatography (silica gel, hexane to 50% ethyl acetate/50% hexane)

Sources & evidence

ORD record
ord-5703788575ec4eb7aea844932a8f0369
Source dataset
uspto-grants-2009_03
Patent number
US07511056B2

Reaction notes

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