A process for the preparation of for the preparation of N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methylpyrazole-3- -carboxamide and of its salts, wherein 1,5-dibromopentane is reacted with a compound of formula (IIIa) ##STR00001## in the presence of Na.sub.2CO.sub.3 in acetonitrile heated at reflux.