| abstract |
Milbemycin derivatives of the formula wherein X is hydrogen or β-halogen, R is methyl, ethyl, isopropyl or sec-butyl and Az represents a 5-membered heterocyclic aromatic ring which is linked in the 1-position and has two to four nitrogen atoms and is unsubstituted or one to two times by C 12 -C 6 alkyl is substituted, and its acid addition salts and metal complex compounds are active preparations for controlling endoparasites and ectoparasites, in particular for controlling animal parasitic nematodes. They can be obtained by appropriate esterification in the 5-position of milbemycin derivatives. The targeted 13-ß-halogenation can be achieved from 14,15-epoxy-milbemycin derivatives via the intermediate stage of Δ 13,14 -15-hydroxy-milbemycines with appropriate halogenating agents. |