Hydrogen Bromide → 2-(5-Cyclopropyl-3-phenyl-isoxazol-4-yl)-imidazo[1,2-a]pyridine

HRID 731669Notes

Reaction equation

HRID 731669 reaction equation
Br[CH2:2][C:3]([C:5]1[C:6]([C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)=[N:7][O:8][C:9]=1[CH:10]1[CH2:12][CH2:11]1)=O.[NH2:19][C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][N:21]=1.Br>C(O)C>[CH:10]1([C:9]2[O:8][N:7]=[C:6]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=3)[C:5]=2[C:3]2[N:19]=[C:20]3[CH:25]=[CH:24][CH:23]=[CH:22][N:21]3[CH:2]=2)[CH2:12][CH2:11]1

Participants

5

Reactant 3

HCID 260Hydrogen BromideHCID 104392-Aminopyridine2×HCID 247398072-Bromo-1-(5-cyclopropyl-3-phenyl-isoxazol-4-yl)-ethanone

Product 1

HCID 690683842-(5-Cyclopropyl-3-phenyl-isoxazol-4-yl)-imidazo[1,2-a]pyridineYield 54.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 2-bromo-1-(5-cyclopropyl-3-phenyl-isoxazol-4-yl)-ethanone (91.8mg, 0.3 mmol) and 2-aminopyridine (28.2 mg, 0.3 mmol) in ethanol (2 mL) containing hydrobromic acid (48%, 16.9 μL, 0.8 mmol) was heated under reflux under argon for 2 h. Another portion of 2-aminopyridine (28.2 mg, 0.3 mmol) was added and heating continued under reflux under argon for 1 h. After cooling to room temperature, the mixture was evaporated and poured onto saturated sodium hydrogen carbonate and extracted with ethyl acetate. The combined organic layers were then washed with water and brine, dried over sodium sulphate and evaporated to leave a yellow oil. Purification by chromatography (SiO2, heptane:ethyl acetate: 100:0 to 50:50) afforded the title compound (49 mg, 54%) which was obtained as an off-white solid. MS: m/e=302.1 [M+H]+.

Workup

  1. temperaturewas heated
  2. temperatureunder reflux under argon for 2 h
  3. temperatureheating
  4. temperatureunder reflux under argon for 1 h
  5. customthe mixture was evaporated
  6. additionpoured onto saturated sodium hydrogen carbonate
  7. extractionextracted with ethyl acetate
  8. washThe combined organic layers were then washed with water and brine
  9. dry with materialdried over sodium sulphate
  10. customevaporated
  11. customto leave a yellow oil
  12. customPurification by chromatography (SiO2, heptane:ethyl acetate: 100:0 to 50:50)

Sources & evidence

ORD record
ord-f73ad2ea70054f498472de732f927c98
Source dataset
uspto-grants-2009_09
Patent number
US07585874B2

Reaction notes

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