Ethanolamine → 3-Bromo-5-(2'-hydroxyethyl)amino-1-methyl-4-nitropyrazole

3 g (10.5 mmoles) of 3,5-dibromo-1-methyl-4-nitropyrazole are heated in a solution of 30 ml ethanolamine in 30 ml ethanol for 15 hours at boiling temperature. The reaction mixture is then poured on 200 ml water, the separated product is filtered, washed with water (20 ml) and vacuum dried. Additional product crystallizes from the filtrate when cooled (5° C.). 2.25 g (81 percent of theory) of 3-bromo-5-(2'-hydroxyethyl)amino-1-methyl-4-nitropyrazole are obtained in the form of yellow crystals with a melting point of 150° C.