Trifluoroacetic acid → 3-Bromo-6-chloroimidazo(1,2-b)pyridazine

HRID 456042Notes

Reaction equation

HRID 456042 reaction equation
[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[N:6]([CH:8]=[CH:9][N:10]=2)[N:7]=1.[Br:11]N1C(=O)CCC1=O.FC(F)(F)C(O)=O>C(#N)C>[Br:11][C:8]1[N:6]2[N:7]=[C:2]([Cl:1])[CH:3]=[CH:4][C:5]2=[N:10][CH:9]=1

Participants

5

Reactant 3

HCID 6422Trifluoroacetic acidHCID 67184N-bromobutanimideHCID 138828Imidazo(1,2-b)pyridazine, 6-chloro-

Product 1

HCID 128723233-Bromo-6-chloroimidazo(1,2-b)pyridazineYield 95%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

To a solution of 6-chloroimidazo[1,2-b]pyridazine (5 g, 32.6 mmol) in acetonitrile (300 ml) was added 1-bromopyrrolidine-2,5-dione (6.37 g, 35.8 mmol) and trifluoroacetic acid (0.75 mL). The resulting solution was allowed to stir at room temperature overnight. The solvent was removed under reduced pressure and the residue was dissolved in EtOAc, washed with NaHCO3 solution, water and brine, dried over Na2SO4 and concentrated in vacuo to afford 7.2 g title compound in 92% yield as a light yellow solid. 1H-NMR (400 MHz, CDCl3) δ ppm 7.91 (d, 1H), 7.79 (s, 1H), 7.12 (d, 1H). LCMS (method A): [MH]+=232/234, tR=4.48 min.

Workup

  1. customThe solvent was removed under reduced pressure
  2. dissolutionthe residue was dissolved in EtOAc
  3. washwashed with NaHCO3 solution, water and brine
  4. dry with materialdried over Na2SO4
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-7f86578b859743bd8fd9340d43d164e6
Source dataset
uspto-grants-2013_07
Patent number
US08497368B2

Reaction notes

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