Bromine → 3-Bromo-7-chloroimidazo[1,2-a]pyridine

HRID 985523Notes

Reaction equation

HRID 985523 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][N:5]2[CH:8]=[CH:9][N:10]=[C:4]2[CH:3]=1.C([O-])(=O)C.[Na+].[Br:16]Br.C(=O)([O-])O.[Na+]>[Br-].[K+].CO>[Br:16][C:8]1[N:5]2[CH:6]=[CH:7][C:2]([Cl:1])=[CH:3][C:4]2=[N:10][CH:9]=1

Participants

7

Reactant 4

HCID 24408BromineHCID 516892Sodium BicarbonateHCID 517045Sodium AcetateHCID 196959017-Chloroimidazo(1,2-a)pyridine

Product 1

HCID 467391183-Bromo-7-chloroimidazo[1,2-a]pyridineYield 80%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 253877Potassium BromideSolvent

Conditions

Temperature
0 °C

Procedure

7-Chloroimidazo[1,2-α]pyridine (3.0 g, 19.7 mmol) and sodium acetate (1.94 g, 23.6 mmol) were dissolved in a saturated solution of potassium bromide in methanol (25 ml) and cooled to 0° C. before adding bromine (3.3 g, 20.7 mmol) dropwise over 5 min. The mixture was allowed to stir for 15 min before pouring onto saturated sodium hydrogencarbonate solution (200 ml). The resulting solid was collected by filtration and dried under high vacuum to give 3-bromo-7-chloroimidazo[1,2-α]pyridine (3.64 g, 80%) as a white solid. 1H NMR (360 MHz, CDCl3) δH 6.92 (1H, dd, J 2 and 7), 7.61 (1H, s), 7.63 (1H, d, J 2), 8.05 (1H, d, J 7).

Workup

  1. filtrationThe resulting solid was collected by filtration
  2. customdried under high vacuum

Sources & evidence

ORD record
ord-1f6bcddbd64b489a8c24ac9b26f2897d
Source dataset
uspto-grants-2005_03
Patent number
US06872731B2

Reaction notes

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