Abstract: Compounds of the formula I and disulfides thereof and salts thereof are important intermediate products for the preparation of compounds having a microbicidal and plant-immunizing action, of the formula III In the compounds of the formulae I and III: X is halogen, n is 0, 1, 2 or 3; Z is CN, CO—A or CS—A, A is hydrogen, halogen, OR1, SR2 and N(R3)R4; R1 to R4 are hydrogen, a substituted or unsubstituted, open-chain, saturated or unsaturated hydrocarbon radical containing not more than 8 carbon atoms, a substituted or unsubstituted cyclic, saturated or unsaturated hydrocarbon radical containing not more than 10 carbon atoms, substituted or unsubstituted benzyl or phenethyl, a substituted or unsubstituted alkanoyl group containing not more than 8 carbon atoms, a substituted or unsubstituted benzoyl group or a substituted or unsubstituted heterocyclyl radical; or R3 and R4, together with the nitrogen atom to which they are bonded, are a 5- or 6-membered, subs