A facile and efficient approach was adopted for the synthesis of a series of novel pyrimido[5,4- c]quinolin-4(3H)-one derivatives. All the synthesized compounds were characterized using spectroscopic data (IR, ¹H NMR, and mass spectrometry) and evaluated for their in vitro antimicrobial activities against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), Gram-negative bacteria (Escherichia coli) as well as fungi (Canibia albican) by broth microdilution method. The antimicrobial screening revealed that the tested compounds showed slightly to moderate antibacterial and antifungal activities.

Key words: pyrimidoquinoline derivative, antimicrobial evaluation, azo-Wittig reaction