: Carbohydrazides and their Schiff bases are important classes of heterocycles that are not only employed in the area of organic chemistry but also have tremendous applications in physical and inorganic chemistry. A series of potentially bioactive compounds containing carbohydrazide functionality and their hydrazone derivatives have been synthesized and screened for antibacterial, anticancer, antifungal and anti-inflammatory, etc. This brief review discloses some synthetic routes to so many reported carbohydrazides, their Schiff bases, their biological activities, and their structure-activity relationship.

The design of the environmentally friendly approach to the synthesis of biologically important compounds without compromising the yield has been the focus of many chemists in recent years. The development of the one-pot synthesis of heterocycles in the presence of Ionic Liquids (ILs), used as both environmental media and catalysts, is efficient and environmentally sustainable. This review highlights the one-pot synthesis of imidazoles in acidic ILs in the past decade. Some reviews have been conducted on imidazoles, such as their pharmacological importance. Hence, we decided to focus on their synthesis in acidic ionic liquids, which the authors are not aware of any published literature.

Crude caffeine was isolated from kola nut, by treating the filtrate obtained from powdered kola nut with lead (II) acetate to precipitate acids and albumins, along with HCl to precipitate lead ions, and to make some insoluble tannins to be soluble, then Na₂CO₃ solution was added to neutralise the acidic HCl solution. Dichloromethane is added to the filtrate to extract the caffeine from the aqueous layer and then distilled to obtain the crude caffeine. The extracted crude caffeine is recrystallized with activated charcoal and tested for its antioxidant capacity, using the DPPH assay, which screens the antioxidant activity of plant extracts. The DPPH (2, 2-diphenyl-1-picrylhydrazyl) in methanol helps to facilitate the extraction of the antioxidant compounds from the sample. Ascorbic acid (Vitamin C) is used as the standard for this assay, due to its appreciable antioxidant activity. The IC₅₀ value was calculated from the graph of % inhibition against concentration, and the extracted caffeine from kola nut was found out to have a high antioxidant activity comparable to that of the standard, ascorbic acid.

An unexpected cyanide-mediated rearrangement of conjugated lactones is described, providing access to novel tricyclic furopyrrolidinones. This reaction occurs in a stoichiometry- and substrate-dependent manner, induced by multiple additions of cyanide to α,β,γ,δ-unsaturated lactones bearing suitable aryl substituents, providing products with adjacent ether, nitrile, and lactam functionalities. Single-crystal X-ray diffraction (SCXRD) studies of two products support the stereochemical assignments, providing evidence of a dynamic equilibrium process.