SYNTHESIS, SPECTRAL, ANTI-CORROSION, ANTI-MICROBIAL STUDIES OF SOME NEW HETEROCYCLIC DERIVATIVES INCORPORATING PIPERIDONE-4 MOIETY

The reaction of 3-Isobutyl-2,6-di(thienyl-2) piperidin-4-one with thiosemicarbazide, Phenacylbromide, 4-aminoantipyrine, N-aminoquinoline-2-one, thiocarbohydrazide afforded. 3-Isobutyl-2,6-di(thienyl-2) piperidin-4-one, thiosemicarbazone 2, 2-(3-isobutyl-2,6-di(thienyl-2)piperidin-4-ylidene)hydrazono)-4-phenyl-2, 3-dihydrothi azole 4, 4-((3-isobutyl-2,6-di(thienyl-2)piperidin-4-ylidene)amino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one5,1-((3-isobutyl-2,6-di(thienyl-2)piperidin-4-ylidene)amino)quinolin-2(1H)-one8,3-Isobutyl-2,6-di(thienyl-2) piperidin-4-thiocarbohydraz one 9, The resulted compounds were reacted with various nucleophiles in order to obtain new heterocyclic derivatives. Chemical structures of all products were confirmed by IR, MS, 1H-, 13C-NMR spectral data. All synthesized compounds were in vitro tested against a standard strain of pathogenic microorganism inclosing Gram +ve bacteria (Staphylococcus aureus), Gram-ve bacteria (Escherichia coli). Compounds 2,3 exerted strong antibacterial activity against (E.coli, Staph. aureus ) while compounds (1,4-10)exerted good activity against (Staphylococcus aureus) more than (E.coli). Ten synthesized piperidone-4 derivatives were tested to determine their ability to inhibit corrosion of mild steel in 1 mol.L-1 H2SO4and measured by polarization measurements the. All ten compounds show good inhibition efficiency in the following order: 2 > 9 > 6 > 7 > 8 > 3 > 4 > 1 > 10 > 5 polarization measurements indicated that these compounds behave as a mixed mode inhibitor ,the studies revealed that the imine nitrogen , the piperidin moiety and the phenyl ring assist largely in corrosion control.