Sulfuric Acid → 1-[4-(Imidazo[1,2-a]pyridin-2-yl)phenyl]ethan-1-one

HRID 1284102Notes

Reaction equation

HRID 1284102 reaction equation
[CH3:1][Mg]I.[N:4]1[C:5]([C:13]2[CH:20]=[CH:19][C:16]([C:17]#N)=[CH:15][CH:14]=2)=[CH:6][N:7]2[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=12.S(=O)(=O)(O)O.[OH-:26].[Na+]>CCOCC.O.O1CCCC1>[C:17]([C:16]1[CH:19]=[CH:20][C:13]([C:5]2[N:4]=[C:8]3[CH:9]=[CH:10][CH:11]=[CH:12][N:7]3[CH:6]=2)=[CH:14][CH:15]=1)(=[O:26])[CH3:1]

Participants

8

Reactant 4

HCID 1118Sulfuric AcidHCID 14798Sodium HydroxideHCID 8211074-imidazo[1,2-a]pyridin-2-ylbenzonitrileHCID 178418373HCID 178418373, compound

Product 1

HCID 215155611-[4-(Imidazo[1,2-a]pyridin-2-yl)phenyl]ethan-1-one

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Procedure

A solution of methylmagnesium iodide (prepared from 3.6 g of magnesium and 22 g of methyl iodide) in 40 ml of ether is added dropwise to a mixture of 6.5 g of 4-(imidazo[1,2-a]pyridin-2-yl)benzonitrile and 50 ml of tetrahydrofuran with stirring on an ice bath. The mixture is heated under reflux for 3 hours, and the reaction mixture is cooled with salt and ice. 100 ml of 50% sulfuric acid is added dropwise to the reaction mixture, water is added, and the whole mixture is adjusted to pH 8 by addition of 20% sodium hydroxide. The crystalline precipitate is filtered off, washed with water and recrystallized from dimethylformamide to give 4.2 g of 2-(4-acetylphenyl)-imidazo[1,2-a]pyridine as colorless crystals melting at 209°-210°C. 2.2 g of the thus-obtained 2-(4-acetylphenyl)-imidazo[1,2-a]pyridine is heated with 0.45 g of sulfur and 10 ml of morpholine under reflux for 6 hours. The reaction mixture is cooled, and ethanol is added. The crystalline precipitate is filtered off and washed with ethanol to give 1.4 g of 4-(imidazo[1,2-a]pyridin-2-yl)phenylacetothiomorpholide as yellowish brown crystals melting at 204°-206°C.

Workup

  1. temperatureThe mixture is heated
  2. temperatureunder reflux for 3 hours
  3. temperaturethe reaction mixture is cooled with salt and ice
  4. additionis added
  5. filtrationThe crystalline precipitate is filtered off
  6. washwashed with water
  7. customrecrystallized from dimethylformamide

Sources & evidence

ORD record
ord-15ce9d84be9546278c8b765da23a2fe7
Source dataset
uspto-grants-1976_08
Patent number
US03978071

Reaction notes

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