Ultrasound Assisted and SO4-2/SnO2-Catalyzed One-Pot Multicomponent Reaction for the Synthesis of 1,2,3,4,6-Pentasubstituted Piperidines

A feasible and prominent comparative study is progressing for the construction of 1,2,3,4,6-pentasubstituted piperidines through a conventional organic synthetic method and an ultrasound-assisted method. This is a one-pot, three-component method achieved by simply available reactants such as aromatic aldehydes, aromatic amines, ethyl acetoacetate, and a little amount of sulfated tin oxide (STO) catalyst (SO4-2/SnO2 -STO) in ethanol as a solvent. In this single-step process, new 4 C-C and 2 C-N bonds are developed, creating an entire moiety. The sonication implants lower the activation energy by cavity bubbles, and the STO catalyst helps to bind the starting materials through the H bond. The target compound is reached by an important Mannich reaction and isomerization. This new protocol has several advantages over previously reported methods, including shorter yields, prolonged work-up procedures, and operational problems. The docking study is performed against the MTNN protein of Mycobacterium tuberculosis..