Antibacterial 3-aminoquinazolin-2,4-diones have formula (I) wherein: R1 and R3 include alkyl, alkenyl, cycloalkyl, aryl, hetero-cyclic, and heteroaryl; R5, R6, and R8 include H, alkyl, alkoxy, halo, NO2, CN, NH2, alkyl and dialkylamino; R7 includes hydrogen, alkyl, cycloalkyl, hetero-cyclic, fused heterocyclic, aryl and fused aryl; J and K are C or N; and pharmaceutically acceptable salts thereof.