Sulfuric Acid → 4-Amino-1-methyl-5-methylaminopyrazole

Participants

Reaction Steps

0.5 g (2.13 mmoles) of 3-bromo-1-methyl-5-methylamino-4-nitropyrazole are hydrogenated in a solution of 220 mg (2.13 mmoles) sulfuric acid in 20 ml water for 14 hours after adding the catalyst as described in method (2). After filtering the catalyst, the filtrate is reduced until dry and the residue is recrystallized from ethanol. 370 mg (78 percent of theory) of 4-amino-1-methyl-5-methylaminopyrazole hydrosulfate are obtained in the form of colorless crystals with a melting point of 185° to 188° C.

Provenance & Evidence