This invention relates to 4-substituted phenylamine derivatives of the general formula (I), wherein R1 to R8 and A have the meanings as defined in description. The invention further relates to methods for their preparation and use of said compounds to fight undesired phytopathogenic microorganisms, and agents for said purpose, comprising said phenylamine derivatives, all according to the invention. This invention further relates to a method for fighting undesired phytopathogenic microorganisms by application of said 4-substituted phenylamine derivatives of general formula (I) to such undesired microorganisms and/or to their habitat, according to the invention.本發明係關於通式(I)之4-經取代之苯胺衍生物,其中,R1至R8及A具有內文所定義之意義。本發明係進一步關於其製備方法與該化合物對抗不欲之植物病原微生物之用途,以及為此目的包括該苯胺衍生物之試劑,全部係根據本發明。本發明係進一步關於根據本發明,藉由施用通式(I)之該4-經取代之苯胺衍生物到此等不欲之微生物及/或到其棲息地來對抗不欲之植物病原微生物之方法。