Synthesis of carboxamide sensors for neurotoxic Cu2+ ions in safer green solvents and reaction conditions

Green amidation is simple and efficient for the synthesis of drugs and biomolecules. Green chemistry synthesis is always directed at achieving sustainability. Neurotoxins are critical targets for metabolic medicines to capture and eliminate from the body. Copper is a fatal brain neurotoxin. The C1-C4 probes were synthesized by reacting 3-coumarin carboxylic acid with 4-phenyl butyl amine, N-ethyl benzylamine, 4-dodecylaniline, and 3,3 - diphenyl propylamine in polar green solvent ethanol. These were tested for their metal-binding ability in environmentally safe aqueous acetonitrile with hyphenated techniques. The probes show significant binding with Cu²⁺ ions in the aqueous acetonitrile. The ascending order of anti-neurotoxin action is C3>C4>C2>C1 seen in the Limit of detection (Lod) values. Also, molecular mechanics (MM2) descriptors firmly point towards their use as drugs.