Synthesis and characterization of a novel series of 1,4‐dihydropyridine analogues for larvicidal activity against Anopheles arabiensis

The new‐fangled bis(4‐substituted benzyl) 4‐(4‐substitued phenyl)‐2,6‐dimethyl‐1,4‐dihydropyridine‐3,5‐dicarboxylate derivatives were synthesized by the union of substituted aryl aldehyde, tert‐butyl acetoacetate, ammonium carbonate with 4‐substituted benzyl alcohol via Hantzsch ester synthesis in aqueous medium under catalyst‐free conditions. The newly synthesized compounds were characterized by spectroscopic techniques such as IR, NMR (¹H and ¹³C), ESI mass, elemental analysis, and single‐crystal X‐ray diffraction. The characterized title compounds were evaluated for the larvicidal activity against Anopheles arabiensis by standard WHO larvicidal assay method using Temephos as standard at 4 μg/ml. The title compounds bis(4‐methoxybenzyl) 2,6‐dimethyl‐4‐(4‐nitrophenyl)‐1,4‐dihydropyridine‐3,5‐dicarboxylate and bis(4‐chlorobenzyl) 2,6‐dimethyl‐4‐(4‐nitrophenyl)‐1,4‐dihydropyridine‐3,5‐dicarboxylate exhibited promising larvicidal activity at 65.6% and 72.2%, respectively, when compared with the standard compound at 98.9%.