2-Bromopropanedial → 6-Bromopyrazolo[1,5-a]pyrimidine

HRID 751299Notes

Reaction equation

HRID 751299 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]=[N:7][C:8]2[N:9]([N:10]=[CH:11][CH:12]=2)[CH:3]=1

Participants

4

Reactant 2

HCID 749452-BromopropanedialHCID 178418806HCID 178418806, compound

Product 1

HCID 222367016-Bromopyrazolo[1,5-a]pyrimidineYield 11.2%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Dissolve 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 the resulting mixture under nitrogen for 2 h. Concentrate under reduced pressure. Dissolve the residue in absolute methanol (150 mL), vacuum filter through a pad diatomaceous earth and concentrate under reduced pressure. Chromatograph on flash silica using a gradient from neat hexane to 50% ethyl acetate/50% hexane to obtain 365 mgs (11%) of the subtitled compound as a light yellow solid. High Resolution Mass Spectrum: 197.9674 (M+1).

Workup

  1. temperaturereflux the resulting mixture 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 diatomaceous earth
  5. concentrationconcentrate under reduced pressure

Sources & evidence

ORD record
ord-c0d955078d424f1d90978cc9a4a19913
Source dataset
uspto-grants-2008_07
Patent number
US07405299B2

Reaction notes

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