Some 5-substituted 3-isounzolecartiouylic wid hytlrazidcs have been prepared for investigation of their anti-lepra1 aetivit v The 5-methyl, n-propyl, and isobutyl compounds showed activity. The 5-methyl compound was superior. Other alkyl residues gave less activity. Aromatic or heterocyclic residues conferred no special activity. Some derivatives and related compounds\ rere prepared.
