The invention relates to fungicidally active compositions that contain at least one compound of the general formula ##STR1## and/or a compound of the formula ##STR2## in which: A denotes the --CH.dbd.CH-- or --C.tbd.C-- group and R.sub.1 and R.sub.2 represent hydrogen or methyl. The active substances according to the invention can be obtained by reacting correspondingly substituted succinic acids, or acid halides, anhydrides or esters thereof, with 3,5-dichloroaniline.