the sulfonamido and halogen groups by a single bond to a quaternary carbon atom and is thus, unlike the thiazides, noriplanar. 111 order to find whether other acidic heterocyclic ring structures could replace the isoindoline ring of I, the conipounds I1 and I11 (Ar= 4'-C1-3'- H2KS02C6H3) and related structures were prepared for testing as diuretics (see Tables I and 11). h/c1 Ar,
