Novel 4-Aryl-1,4-dihydropyridines: Local Anesthetic Agents

Four novel 4-aryl-1,4-dihydropyridines (1-4) were synthesized via a one-pot three-component reaction by condensing aromatic aldehydes, ammonium acetate and ethyl acetoacetate in the presence of 4-(dimethylamino) pyridine (DMAP) as a highly efficient homogenous catalyst. The structures of the synthesized compounds have been deduced from IR, H-1 NMR, HRMS, and single crystal X-ray crystallography. The local anesthetic effect of these derivatives was assessed in comparison to lidocaine as a standard using a rabbit corneal and mouse tail anesthesia model. The results showed that compared with compounds 1-3, compound 4 with thiophene ring exhibited better anesthetic activity.