3-Chloro-2-hydrazino-1,2-dihydropyrazine hydrochloride

4858-85-9

63286-28-2

Step 1: 2,3-Dichloropyrazine (150 g, 1.00 mol) was dissolved in ethanol (700 mL) to which hydrazine monohydrate (124.53 g, 2.11 mmol, 85% aqueous solution) was subsequently added. The reaction mixture was heated under reflux conditions overnight. Upon completion of the reaction, the mixture was cooled and the precipitate was collected by filtration. The resulting solid was washed sequentially with water (100 mL, twice) and cold ethanol (150 mL, twice) and finally dried under reduced pressure to give 2-chloro-3-hydrazinopyrazine (140 g, 96% yield).