Substituted 4,5-dihydroxy-imidazolidine-2-thiones and their use as ectoparasiticides

摘要

The present invention provides, as compounds, the substituted 4,5-dihydroxy-imidazolidine-2-thiones of the general formula <IMAGE> (I) in which R1, R2and R3, which are selected independently of one another each represent hydrogen, optionally substituted alkyl, optionally substituted alkoxy or halogen and R4 represents optionally substituted alkyl, cycloalkyl or alkenyl. It has been found that the compounds of this invention have a powerful ectoparasiticidal action, in particular against acarids.