Synthesis, characterization and antitubercular activities of heterocyclic selenosemicarbazones

Reaction of cyclohexanoneselenosemicarbazone with aldehydes and ketones containing heterocyclic rings (2-oxindole, 6-cholro-2-oxindole, 3-methyl-2-oxindole, isatin, 1-methyl isatin, furfural, pyrrole-2-carboxldehyde) in ethanol yielded, respective, selenosemicarbazones {2-oxindoleselenosemicarbazone (2-HOxsesc,(HL)-L-1), 6chloro-2-oxindole selenosemicarbazone (6-ClHOxsesc, (HL)-L-2), 3-methyl-2-oxindole selenosemicarbazone (3-MeHOxses, (HL)-L-3), isatinselenosemicarbazone (HIstsesc, (HL)-L-4), 1-methyl isatinselenosemicarbazone (1-MeHIstsesc, (HL)-L-5), 2-thiopheneselenosemicarbazone (2-Hthiosesc, (HL)-L-6), 2-furfuralselenosemicarbazone (2-Hfursesc, (HL)-L-7) and 2-pyrrole selenosemicarbazone (2-Hpysesc, (HL)-L-8)}. However the similar reaction with aldehyde containing single aromatic ring (3-chlorobenzaldehyde and 4-chlorobenzaldehyde) formed 1, 2-bis(3-chlorobenzylidiene) hydrazine (A) and 1, 2-bis(4-chlorobenzylidiene) hydrazine (B) rather than selenosemicarbazone. All the synthesized compounds were characterized using IR and NMR (H-1, C-13) spectroscopy. Structure of A and B were confirmed by single crystal X-ray crystallography. The synthesized selenosemicarbazones were tested for their anti-tubercular activities and (HL)-L-1, (HL)-L-3, (HL)-L-5 and (HL)-L-6 are found to exhibit excellent anti-TB activity. The experimental data will give an opportunity to examine their anti-tubercular activities and identify the lead molecule.

Automated summary

A variety of selenosemicarbazones were synthesized through reactions with different aldehydes and ketones. Reactions with aldehydes containing a single aromatic ring resulted in the formation of other compounds instead of selenosemicarbazones. The synthesized compounds were characterized using IR and NMR spectroscopy, and some were found to exhibit excellent anti-TB activity.