Substituted guanidines and diaminonitroethenes, their preparation and use

A compound of formula I ##STR5## wherein R.sup.1 and R.sup.2 are independently hydrogen, trifluoromethyl or halogen;

• R.sup.3 is trifluoromethyl, methoxy or halogen;
• R.sup.4 is straight or branched C.sub.1-12 -alkyl substituted with C.sub.3-8 -cycloalkyl, halogen, hydroxy, aryloxy, arylalkoxy, C.sub.1-6 -alkoxy, C.sub.1-6 -alkylthio, arylthio, C.sub.1-6 -alkylamino, C.sub.1-6 -dialkylamino, heteroaryl, heteroarylalkyl or aryl, wherein the heteroaryl is optionally substituted with halogen or trifluoromethyl;
• or R.sup.4 is C.sub.2-12 -alkenyl, C.sub.2-12 -alkynyl or C.sub.3-8 -cycloalkyl optionally substituted with C.sub.3-8 -cycloalkyl, halogen, hydroxy, aryloxy, arylalkoxy, C.sub.1-6 -alkoxy, C.sub.1-6 -alkylthio, arylthio, C.sub.1-6 -alkylamino, C.sub.1-6 -dialkylamino, heteroaryl, heteroarylalkyl or aryl, wherein the heteroaryl is optionally substituted with halogen or trifluoromethyl;
• or R.sup.4 is Y--R.sup.5, wherein Y is --O--or --N(R.sup.6)--;
• R.sup.5 and R.sup.6 are independently straight or branched C.sub.1-12 -alkyl, C.sub.2-12 -alkenyl, C.sub.2-12 -alkynyl or C.sub.3-8 -cycloalkyl optionally substituted with C.sub.3-8 -cycloalkyl, halogen, hydroxy, heteroaryl, heteroarylalkyl, aryloxy or aryl, wherein the aryl or heteroaryl is optionally substituted with halogen or trifluoromethyl;
• or R.sup.5 and R.sup.6 together with the nitrogen atom form a 3-12 membered mono- or bicyclic system, in which one or more of the carbon atoms may be substituted with nitrogen, oxygen or sulfur, wherein each of these ring systems is optionally mono- or polysubstituted with halogen. C.sub.1-6 -alkyl, hydroxy, C.sub.1-6 -alkoxy, C.sub.1-6 -alkoxy-C.sub.1-6 -alkyl, nitro, amino, cyano, trifluoromethyl, C.sub.1-6 -monoalkyl- or dialkylamino or oxo;
• X is N--CN;
• or a pharmaceutically acceptable salt thereof, or an optical isomer or mixture of optical isomers thereof, or a tautomeric form thereof.