Naphthoquinones are natural and synthetic products that have the ability to generate reactive oxygen species (ROS) through a redox mechanism. This process involves the presence of anions, dianions, superoxide anions and semiquinone radicals that can cause intracellular hypoxia leading to oxidative stress and, consequently, cell death. As a consequence, synthetic and natural naphthoquinones exhibit a sum of biological activities, including antibacterial activity. 

Sulfonamides are structural analogues of p-aminobenzoic acid (PABA), which inhibits folic acid metabolism, an essential factor for bacterial growth. In addition, structural insertions in the sulfonamide structure allowed an extension of its pharmacological applications.

Considering these factors, in this work, we synthesized 1,4-naphthoquinones linked to sulfonamides containing a 1,3-phenylene diamamine linker in order to obtain new new compounds with potential antibacterial activity. To obtain the planned antibacterial compounds, aminonaphtoquinone 1 was reacted with different sulfonyl chlorides 2a-e, thus leading to compounds 3a-e. All compounds had their chemical structures confirmed by hydrogen nuclear magnetic resonance (1H and 13C-NMR), infrared and high resolution mass spectroscopy (HSMRS).