Synthesis and antitubercular activity of N-(2-naphthyl)glycine hydrazide analogues

N-(2-Naphthyl)glycine hydrazide analogues were synthesized and tested for possible in vitro antitubercular activity. N-(2-Naphthyl)alanine hydrazide (3), N-methyl-N-(2-naphthyl)glycine hydrazide (5), N-(6-methoxy-2-naphthyl)glycine hydrazide (7), and 3-(2-naphthylamino)butyric acid hydrazide (23) showed potent inhibitory action against Mycobacterium tuberculosis H37Rv in Youman's medium at concentrations ranging from 0.5 to 10.0 micrograms/mL. These compounds showed significant inhibitory action against isonicotinic acid hydrazide and streptomycin-resistant strains of M. tuberculosis. N-(6-Quinolyl)glycine hydrazide (18) and 3-(2-quinolylamino)butyric acid hydrazide (24), which are bioisosteres of compounds 1 and 23, showed loss of antitubercular activity at low concentrations.