STEREO SELECTIVE SYNTHESIS OF NOVEL PYRAZOLE AND COUMARIN APPENDED BRIDGED PYRANS AS ANTIMICROBIAL AGENTS
Objectives: The aim of the present study was to synthesize a series of novel bridged pyrans as antimicrobial agents.
Methods: An isomeric mixture of 3-(4-ethoxy-10-methyl-8-oxo-2-phenyl-4,8-dihydro-2H-pyrano[3',2':6,7]chromeno[4,3-c]pyrazol-6-yl)-1-phenyl-1H-pyrazole-4-carbaldehydes, 2(a-f) and 3-(4-ethoxy-8-methyl-10-oxo-2-phenyl-4,10-dihydro-2H-pyrano[2',3':5,6]chromeno[4,3-c]pyrazol-6-yl)-1-phenyl-1H-pyrazole-4-carbaldehydes, 3(a-f) were synthesized by the reaction of 3,3'-(7-hydroxy-4-methyl-2-oxo-2H-chromene-6,8-diyl)bis(1-phenyl-1H-pyrazole-4-carbaldehyde) 1(a-f) and ethyl alcohol in the presence of conc. H2SO4. The synthesized compounds were evaluated for their antimicrobial activity.
Results: The structures of the new bridged pyran analogues 3-(4-ethoxy-10-methyl-8-oxo-2-phenyl-4,8-dihydro-2H-pyrano [3',2':6,7] chromeno [4,3-c]pyrazol-6-yl)-1-phenyl-1H-pyrazole-4-carbaldehydes, 2(a-f) and 3-(4-ethoxy-8-methyl-10-oxo-2-phenyl-4,10-dihydro-2H-pyrano [2',3':5,6] chromeno[4,3-c]pyrazol-6-yl)-1-phenyl-1H-pyrazole-4-carbaldehydes, 3(a-f) were confirmed by spectral studies and elemental analysis. The compounds 2e and 3e were having-CONH2 substitution and 2f and 3f were having-CSNH2 substitutions in the pyrazole rings showed antibacterial at minimum concentrations against all the tested organisms.
Conclusions: Results of the antimicrobial activity reveal that some of the synthesized compounds act as potential antimicrobial agents against different fungal and bacterial organisms.
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