Synthesis and antibacterial activity of some 5-nitro-3-phenyliminoindol-2(3H)-ones and their N-Mannich bases

The antimicrobial and antifungal activities of a series of 5-nitro-3-phenyliminoindol-2(3H)-ones and their 1-piperidinomethyl analogues (N-Mannich bases) were investigated. Growth inhibition of Gram-positive bacteria was observed with little or no activity against Gram-negative bacteria. Antifungal activity was absent. The syntheses were accomplished from 5-nitroindol-2,3-dione by condensation with the appropriate aniline followed by formation of the N-Mannich base.