Summary.

As continuance of some previous investigations, a series of twenty five new hydrazones representing derivatives of pyrrole were synthesized and structurally elucidated. New variations were introduced in the nature of the halogen substituent and the length of the „spacer” (-CH2-)n in the acyl chain. The products were evaluated in vitro against Mycobacterium tuberculosis strain H37Rv as potential tuberculostatics. The corresponding activity expressed as % Growth Inhibition was registered. In a comparative structure-activity analysis of the total set of compounds, the effect of the halogen upon the tuberculostatic activity was found to dominate over the length of the acyl chain. The most favorable combination of both structural characteristics comprises Cl-substituted hydrazones with a spacer (-CH2-)2.