Chloroacetaldehyde → 8-(Benzyloxy)-5-bromoimidazo[1,2-a]pyridine

HRID 1922754Notes

Reaction equation

HRID 1922754 reaction equation
[CH2:1]([O:8][C:9]1[C:10]([NH2:16])=[N:11][C:12]([Br:15])=[CH:13][CH:14]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.Cl[CH2:18][CH:19]=O>>[CH2:1]([O:8][C:9]1[C:10]2[N:11]([CH:18]=[CH:19][N:16]=2)[C:12]([Br:15])=[CH:13][CH:14]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

3

Reactant 2

HCID 33ChloroacetaldehydeHCID 596055123-(Benzyloxy)-6-bromopyridin-2-amine

Product 1

HCID 596052618-(Benzyloxy)-5-bromoimidazo[1,2-a]pyridineYield 88%

Procedure

A mixture of 3-benzyloxy-6-bromopyridin-2-ylamine (1.0 g, 3.6 mmol) and chloroacetaldehyde (1.2 mL, 50 wt. % in water) in IMS (12 mL) was stirred at reflux for 1 hour, then concentrated under reduced pressure. The residue was partitioned between an aqueous saturated solution of sodium bicarbonate and EtOAc. The organic layer was separated and washed with brine, dried over Na2SO4, filtered and concentrated. The residue was purified by flash chromatography (Si—PPC, MeOH:Et2O, gradient 0:100 to 1:99) to give 8-Benzyloxy-5-bromo-imidazo[1,2-a]pyridine as an beige solid (960 mg, 88%). LCMS (Method H) RT 3.08 min; [M+H]+ 303 (79Br) and 305 (81Br)

Workup

  1. temperatureat reflux for 1 hour
  2. concentrationconcentrated under reduced pressure
  3. customThe residue was partitioned between an aqueous saturated solution of sodium bicarbonate and EtOAc
  4. customThe organic layer was separated
  5. washwashed with brine
  6. dry with materialdried over Na2SO4
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customThe residue was purified by flash chromatography (Si—PPC, MeOH:Et2O, gradient 0:100 to 1:99)

Sources & evidence

ORD record
ord-42191a94ea924b70b1a77d429cd7e25e
Source dataset
uspto-grants-2012_05
Patent number
US08173650B2

Reaction notes

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