Sulfuric Acid → 3,5-Dibromopyrazin-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

A solution of 12.65 g of 2-amino-3,5-dibromo-pyrazine and 18.5 ml of 96% sulfuric acid is added dropwise to a solution of 3.45 g of sodium nitrite and 27.5 ml of 96% sulfuric acid at 0° to 5° C. The mixture is then allowed to warm to 20° C. in the course of 2 hours and is stirred at 20°-25° C. for a further 15 hours. The reaction mixture is poured into ice and the product is filtered off, washed with ice-water and dried to give 5.8 g of 3,5-dibromo-pyrazin-2-one.

Provenance & Evidence