4-Bromophenol → 2-(4-Bromophenoxy)imidazo[1,2-a]pyridine

HRID 82643Notes

Reaction equation

HRID 82643 reaction equation
Cl[C:2]1[N:3]=[C:4]2[CH:9]=[CH:8][CH:7]=[CH:6][N:5]2[C:10]=1[C:11]([O:13][CH2:14][CH3:15])=[O:12].[CH:16]1[C:21]([OH:22])=[CH:20][CH:19]=[C:18]([Br:23])[CH:17]=1.[H-].[Na+]>CO>[Br:23][C:18]1[CH:19]=[CH:20][C:21]([O:22][C:2]2[N:3]=[C:4]3[CH:9]=[CH:8][CH:7]=[CH:6][N:5]3[C:10]=2[C:11]([O:13][CH2:14][CH3:15])=[O:12])=[CH:16][CH:17]=1.[Br:23][C:18]1[CH:19]=[CH:20][C:21]([O:22][C:2]2[N:3]=[C:4]3[CH:9]=[CH:8][CH:7]=[CH:6][N:5]3[CH:10]=2)=[CH:16][CH:17]=1

Participants

6

Reactant 3

HCID 78084-BromophenolHCID 24758Sodium hydrideHCID 21643308Ethyl 2-chloroimidazo[1,2-a]pyridine-3-carboxylate

Product 2

HCID 679931672-(4-Bromophenoxy)imidazo[1,2-a]pyridineHCID 67993479Ethyl 2-(4-bromophenoxy)imidazo[1,2-a]pyridine-3-carboxylate

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
100 °C

Procedure

Ethyl 2-chloroimidazo[1,2-a]pyridine-3-carboxylate (2.00 g) was added to a solution of p-bromophenol (1.617 g) and NaH (0.427 g) in DMF(dry) (10 ml) at 100° C. The mixture was stirred at 100° C. under a dry atmosphere overnight. The reaction mixture was diluted with MeOH, and concentrated in vacuo. The residue was purified by column chromatography (silica gel, eluted with 0%-30% EtOAc in hexane) to give ethyl 2-(4-bromophenoxy)imidazo[1,2-a]pyridine-3-carboxylate (1.5 g) as a colorless solid and 2-(4-bromophenoxy)imidazo[1,2-a]pyridine (530 mg) as a colorless solid. The mixture of 2-(4-bromophenoxy)imidazo[1,2-a]pyridine (410 mg), 1,3-dihydro-2H-pyrrolo[2,3-b]pyridine-2-one (164 mg), trans-N,N′-dimethylcyclohexane-1,2-diamine (174 mg), copper(I) iodide (116 mg), K2CO3 (338 mg) and THF(dry) (5 mL) was heated at 180° C. for 3 h under microwave irradiation. The solid was removed by filtration, and the filtrate was concentrated in vacuo. The residue was purified by column chromatography (silica gel, EtOAc/hexane) to give the title compound (72 mg) as an orange solid (mixture with 1,3-dihydro-2H-pyrrolo[2,3-b]pyridine-2-one, ca. 20% purity).

Workup

  1. concentrationconcentrated in vacuo
  2. customThe residue was purified by column chromatography (silica gel, eluted with 0%-30% EtOAc in hexane)

Sources & evidence

ORD record
ord-effb80ab4ab64e6da40e2363305d6ebd
Source dataset
uspto-grants-2014_09
Patent number
US08846713B2

Reaction notes

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