5-Nitroisatin is a useful reactant for the synthesis of antibacterial, antifungal, antimycobacterial, antimicrobial, ans antitubercular agents. 5-Nitroisatin is also used to synthesize spiro[indole-thiazolidinones], anticonvulsant agents, human transglutaminase 2 inhibitors, anthelmic agents, acetylcholinesterase inhibitors, and anti-HIV agents.