Synthesis and In-vivo Bioactivity Studies of Some New Hydrazide Schiff Bases and Mannich Bases of Indole Derivatives

Abstract

The anti-inflammatory, analgesic, and antiulcer activities of eight new hydrazide Schiff bases and eight new Mannich bases of indole derivatives were investigated. 2-Methyl-1H-indole-3-carboxylate (III) on hydrazinolysis gave 2-methyl-1H-indole-3-carbohydrazide (IV), which on reaction with aldehydes gave corresponding hydrazide Schiff bases Va–Vh. The reaction of IV with formaldehyde, different aliphatic, aromatic, and heterocyclic amines afforded the Mannich bases of indole derivatives (VIa–VIe). The results of biological studies revealed that Schiff bases with 2,4-dichlorobenzaldehyde (Vh) and 2-chlorobenzaldehyde (Vb) were potent anti-inflammatory, analgesic, and antiulcer activities. Mannich bases (VIh and VIc) having -NO2 and -Cl groups in the paralocation of the heterocyclic nucleus displayed effective anti-inflammatory, analgesic, and antiulcer activities.