2-Bromo-4'-methylacetophenone → 2-(4-Methylphenyl)-6-nitroimidazo[1,2-a]pyridine

HRID 35517

Reaction equation

HRID 35517 reaction equation
Br[CH2:2][C:3]([C:5]1[CH:10]=[CH:9][C:8]([CH3:11])=[CH:7][CH:6]=1)=O.[NH2:12][C:13]1[CH:18]=[CH:17][C:16]([N+:19]([O-:21])=[O:20])=[CH:15][N:14]=1>C(O)CC.ClCCl>[CH3:11][C:8]1[CH:9]=[CH:10][C:5]([C:3]2[N:12]=[C:13]3[CH:18]=[CH:17][C:16]([N+:19]([O-:21])=[O:20])=[CH:15][N:14]3[CH:2]=2)=[CH:6][CH:7]=1

Participants

5

Reactant 2

HCID 692722-Bromo-4'-methylacetophenoneHCID 778882-Amino-5-nitropyridine

Product 1

HCID 8523592-(4-Methylphenyl)-6-nitroimidazo[1,2-a]pyridineYield 23%

Reagents, catalysts & solvents 2

HCID 10311-PropanolSolventHCID 6344DichloromethaneSolvent

Procedure

81 g (0.38 mole) of 1-bromo-2-(4-methylphenyl)-2-ethanone and 53 g (0.38 mole) of 2-amino-5-nitropyridine are reacted in 900 ml of n-propanol. The solution is maintained under reflux, the reaction being followed by thin layer chromatography. When there is no further change, the mixture is evaporated to dryness. The residue is taken up with water and treated with ammonia solution until the pH>8. The insoluble material is filtered off and dried, and then treated with dichloromethane. The insoluble portion is recrystallized in ethyl acetate, which yields a first crop. The mother liquors are then combined with the portion soluble in dichloromethane, the mixture is concentrated and a second crop of product is obtained. The two crops are purified separately by chromatography. 22 g (23%) of yellow solid are obtained overall. M.p. 205°-206° C.

Workup

  1. temperatureThe solution is maintained
  2. temperatureunder reflux
  3. customthe mixture is evaporated to dryness
  4. additiontreated with ammonia solution until the pH>8
  5. filtrationThe insoluble material is filtered off
  6. customdried
  7. additiontreated with dichloromethane
  8. customThe insoluble portion is recrystallized in ethyl acetate
  9. customwhich yields a first crop
  10. concentrationthe mixture is concentrated
  11. customa second crop of product is obtained
  12. customThe two crops are purified separately by chromatography

Sources & evidence

ORD record
ord-d1b684744fdd42abbc927fc9f2d2c369
Source dataset
uspto-grants-1988_08
Patent number
US04767755

Linked notes

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