2-Aminopyridine → 2-(3-bromophenyl)imidazo[1,2-a]pyridine

HRID 251769Notes

Reaction equation

HRID 251769 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([C:8](=O)[CH3:9])[CH:5]=[CH:6][CH:7]=1.BrBr.[NH2:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][N:15]=1.C(=O)([O-])O.[Na+]>O.C(O)(=O)C>[Br:1][C:2]1[CH:3]=[C:4]([C:8]2[N:13]=[C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][N:15]3[CH:9]=2)[CH:5]=[CH:6][CH:7]=1

Participants

7

Reactant 4

HCID 104392-AminopyridineHCID 165023'-BromoacetophenoneHCID 24408Bromine2×HCID 516892Sodium Bicarbonate

Product 1

HCID 8682112-(3-bromophenyl)imidazo[1,2-a]pyridineYield 26%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 962WaterSolvent

Procedure

Dissolving 10 g (50 mmol) of 3′-bromoacetophenone into 20 milliliter of acetic acid and adding 7.0 g (44 mmol) of bromine at the temperature of about 5 to 10° C., stirred at the temperature of about 5 to 10° C. for 4 hours until the color of bromine disappeared. After completion of the reaction, adding water and an extraction was carried out using dichloro-methane. Further, washing with water, dried with the use of sodium sulfate. The solvent was removed by distillation and the resultant crude 2,3′-dibromo acetophenone was dissolved into 30 milliliter of ethanol, adding 5.0 g (53 mmol) of 2-aminopyridine and 7.0 g of sodium hydrogen carbonate, the resultant suspension was refluxed under heating for 8 hours. After completion of the reaction, separation with filtration was carried out and resultant crystals were washed with water and methanol, thereby obtaining 3.5 g of 2-(3-bromo-phenyl)-imidazo [1,2-a] pyridine (yield: 26%).

Workup

  1. customAfter completion of the reaction
  2. extractionan extraction
  3. washFurther, washing with water
  4. dry with materialdried with the use of sodium sulfate
  5. customThe solvent was removed by distillation
  6. dissolutionthe resultant crude 2,3′-dibromo acetophenone was dissolved into 30 milliliter of ethanol
  7. temperatureunder heating for 8 hours
  8. customAfter completion of the reaction, separation
  9. filtrationwith filtration
  10. washresultant crystals were washed with water and methanol

Sources & evidence

ORD record
ord-1acff3265b2d4d45a1dcbeca68f32d05
Source dataset
uspto-grants-2011_01
Patent number
US07867629B2

Reaction notes

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