Antimycobacterial activity of diphenylpyraline derivatives.

2-Substituted derivatives of diphenylpyraline and their 1-phenyl and 1-phenethyl analogues have been prepared in several steps from dihydropyridine-2(1H)-thiones. The structures of all new compounds have been confirmed by NMR spectroscopy. Their activity against Mycobacterium tuberculosis H(37)Rv as well as their cytotoxicity against human cells (HEK-293) have been determined via in vitro assays. The antimycobacterial potency was in general increased by substitution in ring position 2. The most promising modifications were a 2-isopropyl derivative and a 1,2-diphenyl analogue.