Kumada Cross Coupling Reaction for the Synthesis of Quinazoline Derivatives, Evaluation of Their Antibacterial Activity and Docking Studies

Abstract

A series of C7-substituted-2-morpholino-N-(pyridin-2-ylmethyl)quinazolin-4-amine derivatives 3a–3t were synthesized by using Nickel catalyzed Kumada cross coupling reaction. The structure of the key intermediate 2 was assigned using 2D COSY and 2D NOESY correlation spectrum. All the target compounds were characterized and tested for their antibacterial activity against Gram-positive organisms such as Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, and Gram-negative organisms such as Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumonia. The results indicated that compounds 3g–3m exhibited potent antibacterial activity with MIC values ranging from 1.17 to 4.68 μg/mL. These results are expected to be of help in understanding the structure activity relationship and further enable us to design novel antibacterial agents. Molecular docking of Escherichia coli Biotin Carboxylase (EcBC) enzyme was also performed in order to study the interactions of the synthesized compounds.