Pharmaceutical compositions are prepared which comprise a diuretically effective amount, a saluretically effect amount or an antihypertensive amount of a compound of the formula SPC1 Or a pharmaceutically acceptable non-toxic salt thereof, wherein R is aryl which is either unsubstituted or substituted by A. 1, 2 or 3 identical or different substituents selected from the group consisting of halogen, alkyl of 1 to 8 carbon atoms, alkoxy of 1 to 8 carbon atoms, alkenoxy of 2 to 6 carbon atoms, cycloalkyl of 5 to 7 carbon atoms, trifluoromethyl, trifluoromethoxy and phenyl; B. 1 or 2 identical or different substituents selected from the group consisting of nitro, cyano, lower alkylamino of 1 to 4 carbon atoms, a carbonamido moiety of the formula EQU1 and a sulphonamido moiety of the formula EQU2 wherein R1 and R2 are each hydrogen or straight or branched chain alkyl of 1 to 4 carbon atoms, or R1 and R2 together with the nitrogen atom to which they are attached are linked together to form a 5-, 6- or 7-membered heterocyclic ring wherein the nitrogen atom is the only heteroatom or wherein oxygen is also present as a ring member; C. one substituent selected from the group consisting of dialkylamino of 1 to 4 carbon atoms in each alkyl moiety, nitro, cyano and SOn -alkyl of 1 to 4 carbon atoms, wherein n is 0, 1 or 2; D. one substituent selected from the group consisting of a moiety of the formula EQU3 wherein R1 and R2 are as above defined, nitro, cyano, a carbonamido moiety of the formula EQU4 wherein R1 and R2 are as above defined, a sulphonamide moiety of the formula EQU5 wherein R1 and R2 are as above defined, and SOn -alkyl of 1 to 4 carbon atoms, wherein n is 0, 1 or 2, and 1 or 2 substituents selected from the group consisting of alkyl of 1 to 8 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen and trifluoromethyl; E. an annellated-branched or unbranched, saturated or unsaturated, 5-, 6- or 7-membered isocyclic or heterocyclic ring having 1 or more heteroatoms selected from the group consisting of oxygen and sulphur and wherein said aryl moiety is either unsubstituted or chlorosubstituted; F. --O--(CH2)n' --N(alkyl)2, wherein the alkyl groups contain a total of 2 to 4 carbon atoms and n'is 2 or 3; or G. two different substituents selected from the group consisting of alkyl of 1 to 8 carbon atoms, phenyl, halogen, alkoxy of 1 to 8 carbon atoms, trifluoromethyl, trifluoromethoxy, lower alkylamino, nitro, cyano, SOn --alkyl of 1 to 4 carbon atoms, wherein n is 0, 1 or 2, a carbonamido moiety of the formula EQU6 and a sulphonamido moiety of the formula EQU7 wherein R3 and R4 are each hydrogen or alkyl of 1 to 4 carbon atoms; in combination with a pharmaceutically acceptable non-toxic inert diluent or carrier. Diuretic therapy, saluretic therapy and antihypertensive therapy is effected in humans and animals by administering an effective amount of the active ingredient as above defined.