Dimethylformamide → 5-(4-acetamidophenyl)-2(1H)-pyrazinone

HRID 637484Notes

Reaction equation

HRID 637484 reaction equation
[C:1]([N:4]([C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)O)(=[O:3])[CH3:2].Cl[C:13]1[CH:18]=[N:17][CH:16]=[CH:15][N:14]=1.[H-].[Na+].CN(C)C=[O:24]>O>[C:1]([NH:4][C:6]1[CH:11]=[CH:10][C:9]([C:16]2[N:17]=[CH:18][C:13](=[O:24])[NH:14][CH:15]=2)=[CH:8][CH:7]=1)(=[O:3])[CH3:2]

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 24758Sodium hydrideHCID 73277ChloropyrazineHCID 115251N-Phenylglycolhydroxamate

Product 1

HCID 69179095-(4-acetamidophenyl)-2(1H)-pyrazinone

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

N-Acetylphenylhydroxylamine (100 g) and 2-chloropyrazine (79 g) were dissolved in anhydrous dimethylformamide (500 ml). Sodium hydride (50% oil; 46 g) was added in portions over 11/2 hours, ensuring that the temperature was maintained between 20°-40° C. The reaction mixture was cooled, diluted with water (2500 ml); washed with dichloromethane (4 times) and filtered through diatomaceous earth. Acetic acid was slowly added with stirring to take the pH of the filtrate to 5-6. During this addition crystalline solid formed. After 30 minutes, this was collected by filtration, washed with very dilute acetic acid and dried at 60° C. to yield 5-(4-acetamidophenyl)-2-(1H)-pyrazinone (94.6 g).

Workup

  1. temperaturewas maintained between 20°-40° C
  2. temperatureThe reaction mixture was cooled
  3. washwashed with dichloromethane (4 times)
  4. filtrationfiltered through diatomaceous earth
  5. additionAcetic acid was slowly added
  6. customDuring this addition crystalline solid formed
  7. filtrationthis was collected by filtration
  8. washwashed with very dilute acetic acid
  9. customdried at 60° C.

Sources & evidence

ORD record
ord-c48e66c0a44b4ffe8b27c152fc6da356
Source dataset
uspto-grants-1985_12
Patent number
US04556711

Reaction notes

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