Di:bromo bis-pyrazolyl methane prepn.

摘要

Dibromo 1,1'-bis-pyrazolyl methane of formula (III), with anti-parasite activity is made by (a) reacting bromo-pyrazolyl methyl hydrazine of formula (I) with a 1,3-dicarbonyl cpd. of formula (II) in presence of HCl in ethanol under reflux; (b) removing the solvent by evaporation and treating the residue with satd. Na2CO3 soln.: and (c) extracting with diethyl ether and re-crystallising from ethanol.