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

Participants

Reaction Steps

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).

Provenance & Evidence