Compounds of formula (III): ##STR1## wherein R.sup.5 is a single substituent in position 2 or 3 of the phenyl ring and when in the 2-position R.sup.5 is a chlorine atom, a methyl group or a nitro group; and R.sup.6 is a hydrogen atom or a CO.CH.sub.3 group may be prepared by methods analogous to those known in the art, for example, by reaction of the corresponding nitrothiazolyl benzamide with the corresponding halo(di)acetamide. The compounds of formula (III) have schistosomicidal activity and may be administered either as the compound alone or as a pharmaceutical formulation.