Trityl chloride → 3H-Imidazo[4,5-b]pyridine, 6-bromo-3-(triphenylmethyl)-

HRID 241018

Reaction equation

HRID 241018 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[NH:10][CH:9]=[N:8][C:5]2=[N:6][CH:7]=1.[H-].[Na+].[C:13]1([C:19](Cl)([C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)[C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=2)[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1>CN(C)C=O>[Br:1][C:2]1[CH:3]=[C:4]2[N:10]=[CH:9][N:8]([C:19]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=3)([C:26]3[CH:27]=[CH:28][CH:29]=[CH:30][CH:31]=3)[C:20]3[CH:21]=[CH:22][CH:23]=[CH:24][CH:25]=3)[C:5]2=[N:6][CH:7]=1

Participants

5

Reactant 3

HCID 6456Trityl chlorideHCID 24758Sodium hydrideHCID 9115786-Bromo-4H-imidazo[4,5-b]pyridine

Product 1

HCID 668203913H-Imidazo[4,5-b]pyridine, 6-bromo-3-(triphenylmethyl)-Yield 37.2%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

To a solution of 6-bromo-1H-imidazo[4,5-b]pyridine (2.7 g, 11.0 mmol) in dimethylformamide (30 mL) at 0° C. was added 60% sodium hydride in mineral oil (0.53 g, 13.2 mmol) and the reaction mixture was stirred for 30 minutes, followed by the addition of a solution of triphenylmethyl chloride (3.2 g, 11.55 mmol) in dimethylformamide (5 mL). The reaction mixture was stirred at room temperature for 24 hours then quenched by the careful addition of water then partitioned with ethyl acetate (250 mL). The organic phase was washed with 10% aqueous citric acid (2×, 100 mL), brine (100 mL), saturated sodium bicarbonate (100 mL), brine (100 mL) then dried over anhydrous sodium sulfate, filtered and concentrated. Silica gel chromatography (hexane ethyl acetate 9:1 to 4:1) provided 6-bromo-3-trityl-3H-imidazo[4,5-b]pyridine (1.8 g, 37%). 1H NMR (400 MHz, CDCl3): 8.18 (d, 1H), 8.14 (d, 1H), 8.02 (s, 1H), 7.36-7.28 (m, 10H), 7.18-7.14 (m, 5H) and 6-bromo-1-trityl-1H-imidazo[4,5-b]pyridine (2.9 g, 60%) 1H NMR (400 MHz, CDCl3): 8.50 (d, 1H), 8.14 (s, 1H), 7.38-7.34 (m, 10H), 7.16-7.12 (m, 5H), 6.84 (d, 1H).

Workup

  1. stirringThe reaction mixture was stirred at room temperature for 24 hours
  2. customthen quenched by the careful addition of water
  3. customthen partitioned with ethyl acetate (250 mL)
  4. washThe organic phase was washed with 10% aqueous citric acid (2×, 100 mL), brine (100 mL), saturated sodium bicarbonate (100 mL), brine (100 mL)
  5. dry with materialthen dried over anhydrous sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-09588231a0d243188ff5c4647a272729
Source dataset
uspto-grants-2014_02
Patent number
US08648066B2

Linked notes

Loading…