Abstract: Novel 1,3,4-oxadiazolone-(2) compounds of the formula ##STR1## wherein Y denotes carboxy optionally functionally modified or optionally substituted phenyl or a five-membered heterocycle optionally substituted and selected from the group consisting of: furan, thiophen, oxazole, imidazole, oxadiazole, oxadiazolone, triazole, benzofuran, thionaphthalene, benzoxazole, benzimidazole, and benzotriazole, R denotes hydrogen, alkyl or optionally substituted phenyl, n denotes 0 and 1 and the rings A and B carry optionally further non-chromophoric substituents. These compounds may be used as optical brighteners.

Abstract: 3-(N-Alkylcarbamyl)-5-(carboalkoxy)-1,3,4-oxadiazole-2-thione compound having the structural formula ##STR1## wherein R is alkyl having 1 to 4 carbon atoms and R.sup.1 is alkyl having 1 to 4 carbon atoms, and their use as anti-inflammatory agents.

Abstract: New and valuable polycyclic compounds which contain nitrogen-containing rings and have a strong action on plants, agents for influencing plant growth containing these compounds, and a method of influencing plant growth with these compounds.

Abstract: New herbicidally active compounds have the formula ##STR1## wherein R.sup.1 is H, alkyl, alkenyl, cycloalkyl, R.sup.2 is CF.sub.3, NO.sub.2, CN, halogen, alkyl, alkoxy or alkyl, and --X--Y--Z-- is ##STR2## in which R.sup.3 is H, or alkyl, R.sup.4 is H, alkyl or cycloalkyl, R.sup.5 is H or alkyl or when --Y--Z-- contains two vicinal R.sup.4 groups then these R.sup.4 groups taken together with the ring carbon atoms to which they are attached form a saturated or unsaturated hydrocarbyl ring containing 5 or 6 carbon atoms.