Synthesis, Characterization and Antimicrobial Evaluation of Novel Mannich Bases Containing Pyrazole-5-One Phosphonates

Abstract

Background: Newly synthesised compounds of phosphonates were prepared by condensation of diethylphosphate with imine which undergoes a reaction of mannich bases with pyrazole containing schiffs base. The base was prepared by condensation of aldehyde with primary amine. These newly synthesised derivatives were characterised by spectral analysis. Objective: Mannich bases are very important to synthesize wide variety of natural products and pharmaceuticals. Method: Thin Layer Chromatography was performed on aluminum sheet of silica gel 60F254, E-Merk, Germany using iodine as visualizing agent. IR Spectra were recorded as KBr pellets on Perkin-Elmer 1000 units, instruments. All 1H and 13C-NMR spectra were recorded on a Varian XL-300 spectrometer operating at 400MHz and 75 MHz. 31P-NMR spectra were recorded on a Varian XL-spectrometer operating at 161.89MHz. The compounds were dissolved in dimethylsulfoxide and Chemical shifts were referenced to Trimethylsilane (1H and 13C-NMR) and 85% phosphoric acid (31P-NMR). Results: Some of the novel synthetic compounds of Pyrazole Mannich base-Phosphonates showed great potential in field of medicinal chemistry and good biological activity. Conclusion: It can be concluded that this class of compounds certainly holds great potential for the discovery of novel classes of antimicrobial agents.