Abstract: Selective inhibitors of benzylaminoxidases, said inhibitors consisting of compounds of the general formula I ##STR1## wherein X is a group C--R.sup.4 or a nitrogen atom, R.sup.1 and R.sup.2, which can be the same or different from each other, represent hydrogen, hydroxyl groups, alkoxyl groups, or alkyl, alkenyl, hydroxyalkyl, alkoxyalkyl, hydroxyalkoxyalkyl, hydroxyalkoxyl, alkoxyalkoxyl, hydroxyalkoxyalkoxyl, phenoxyl or phenoxyalkyl groups or their substitution derivatives in the phenoxyl group, provided that no more than one of the same be hydrogen, and one or more of the symbols R.sup.3, R.sup.4 or R.sup.5 are hydrogen atoms or alkyl or hydroxyl or alkoxyl or hydroxyalkyl or hydroxyalkoxyl or hydroxyalkoxyalkyl or haloalkyl or carbonyl or carboxylic or ester or amido or nitrile or sulfonic groups or halogen atoms or nitro groups.