Abstract: There are described new compounds of formula ##STR1## in which E is selected from the group consisting of residues of formula ##STR2## in which R" is selected from the group consisting of amino, vinyl, allyl, ethynyl, C.sub.1 -C.sub.5 alkyl, C.sub.1 -C.sub.5 alkoxy, or C.sub.1 -C.sub.5 alkylthio or a C.sub.1 -C.sub.5 alkyl group susbstituted by at least one halogen atom; and hydrogen; in which R.sup.1 and R.sup.2 are each selected from the group consisting of hydrogen, halogen, methyl and ethyl; and R' is selected from substituted phenyl when R" is other than hydrogen, and phenyl, thienyl and substituted phenyl and thienyl when R" is hydrogen.The compounds are useful in the control of parasites.Certain of the compounds have antimicrobial properties.

Abstract: 1,2,4-Oxadiazoles having as 3- and 5-substituents a hydrogen atom, an aliphatic, cycloaliphatic, araliphatic, aryl or heterocyclic group, or a carbamoyl group of the formula -- CONR.sup.1 R.sup.2 where R.sup.1 & R.sup.2 which can be the same or different, are hydrogen atoms or aliphatic, cycloaliphatic, araliphatic or aryl groups or, taken with the N atom, a heterocvolic ring; provided that at least one of the 3- or 5-substituents is an N-substituted carbamoyl group. Antimicrobial activity, and particularly antiviral, antiparasitic and antibacterial activity is shown in this group. The corresponding oxadiazolins are also described and are useful intermediates in the preparation of the oxadiazoles.