3-Ethoxybenzoic acid → 6-bromo-2-(3-ethoxyphenyl)-1H-imidazo[4,5-b]pyridine

HRID 1437461Notes

Reaction equation

HRID 1437461 reaction equation
[NH2:1][C:2]1[C:7]([NH2:8])=[CH:6][C:5]([Br:9])=[CH:4][N:3]=1.[CH2:10]([O:12][C:13]1[CH:14]=[C:15]([CH:19]=[CH:20][CH:21]=1)[C:16](O)=O)[CH3:11].P(Cl)(Cl)(Cl)=O.[OH-].[Na+]>>[Br:9][C:5]1[CH:6]=[C:7]2[NH:8][C:16]([C:15]3[CH:19]=[CH:20][CH:21]=[C:13]([O:12][CH2:10][CH3:11])[CH:14]=3)=[N:1][C:2]2=[N:3][CH:4]=1

Participants

5

Reactant 4

HCID 121263-Ethoxybenzoic acidHCID 14798Sodium HydroxideHCID 24813Phosphorus oxychlorideHCID 6911565-Bromopyridine-2,3-diamine

Product 1

HCID 230260406-bromo-2-(3-ethoxyphenyl)-1H-imidazo[4,5-b]pyridineYield 51.2%

Conditions

Temperature
120 °C

Procedure

A mixture of 2,3-diamino-5-bromopyridine (Compound of Reference Example 1) (1.13 g), 3-ethoxybenzoic acid (997 mg) and phosphorus oxychloride (24 ml) was stirred at 120° C. for 2 hours and poured onto ice. The mixture was neutralized with 8 N sodium hydroxide, stirred for 20 minutes and extracted with ethyl acetate-tetrahydrofuran (3:1, v/v). The organic layer was washed with water, dried over MgSO4. The solvent was distilled off under reduced pressure and the resulting crystals were collected by filtration to obtain 6-bromo-2-(3-ethoxyphenyl)-1H-imidazo[4,5-b]pyridine (978 mg, 51%).

Workup

  1. additionpoured onto ice
  2. stirringstirred for 20 minutes
  3. extractionextracted with ethyl acetate-tetrahydrofuran (3:1
  4. washThe organic layer was washed with water
  5. dry with materialdried over MgSO4
  6. distillationThe solvent was distilled off under reduced pressure
  7. filtrationthe resulting crystals were collected by filtration

Sources & evidence

ORD record
ord-67aa08d81f6449efa226d32031167afb
Source dataset
uspto-grants-2009_11
Patent number
US07622479B2

Reaction notes

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