One-pot synthesis of diphenyl pyrazolylmethylanilines via reductive amination using NaBH4/I2 and their antimicrobial screening

Abstract  

Direct reductive amination of 1,3-diphenyl-1H-pyrazole-4-carbaldehyde and 3-(4-methylphenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde with various substituted aromatic amines using NaBH₄ in the presence of I₂ as reducing agent is described. The reaction has been carried out in anhydrous methanol under neutral conditions at room temperature. The structure of newly synthesized diphenyl pyrazolylmethylanilines was established on the basis of IR, ¹H, ¹³C NMR, and mass spectral data. All diphenyl pyrazolylmethylaniline derivatives were tested in vitro for their antifungal and antibacterial activity against different strains of fungi and bacteria. Most of the compound exhibited considerable antifungal activity but poor antibacterial activity against the test strains.