Process for the synthesis of 1-alkyl-3-hydroxy-5-halo-1,2,4-tri-azoles, and novel hydrazine derivatives

摘要

The invention relates to a process for the synthesis of 1-alkyl-3-hydroxy-5-halo-1,2,4-triazoles, which are intermediates in the synthesis of pesticides, by reaction of a 1-alkyl-3,5-dioxo-1,2,4-triazole with an ionic halogenating agent. The reaction is carried out in the presence of a nitrogen-containing catalyst which is selected from amongst tertiary amines and their hydrohalides, heterocyclic amines and their hydrohalides, and the N,N-disubstituted amides. The 1-alkyl-3-hydroxy-5-halo-1,2,4-triazoles can be prepared from alkylhydrazines by the process according to the invention without use of the very toxic cyanogen halides. The invention further relates to 1-carbamoyl-1-isopropylhydrazine and the alkyl 2-carbamoyl-2-isopropylhydrazinecarboxylates, which are novel hydrazine derivatives.