Organic compounds

摘要

The invention relates to compounds of formula I wherein R₁, R₂, R₃, R₄, R₅, R₆, R₈, R_8', R₉, W, X, A₁, A₂, a, b and c have the significances given in the specification, and optionally the enantiomers thereof. The active ingredients have advantageous pesticidal properties. They are especially suitable for controlling parasites on warm-blooded animals.