The N2,N4-disubstituted pyrimidine-2,4-diamine derivative compounds are antibacterial agents having broad spectrum antibacterial activity. The present N2,N4-disubstituted pyrimidine-2,4-diamine compounds have antimicrobial activity against various susceptible and resistant gram-positive and gram-negative bacteria as well as drug resistant bacteria, such as MRSA and VRSA. The molecular target of these compounds was identified as DNA Gyrase B. Based on their pharmacological profiles, the present compounds may find important clinical applications for severe infectious diseases and tuberculosis.