The C-N Nucleophilic Substitution Reaction Of α-bromoheterocyclic Ethanone And Substituted Piperidine

Aromatic heterocyclic compounds are a class of important fine chemical intermediates for the medicines and agricultural chemicals, and were especially applied widely in the pharmaceutical field. Accordingly, great attention has been paid to the construction of functionalized piperidine compounds. Herein, the C-N nucleophilic substitution reaction was carried out usingα-bromo-aromatic heteroethanone and substituted piperidine as the substrate. First, 2-bromo-1-(thiophen-2-yl)ethanone was synthesized by bromination of aromatic heteroethanone using tetrabutylammo- nium tribromides as brominating agent. Secondly according to the literature,the replaced piperidine hydrochloride was synthesised by the C-O nucleophilic substitution. And then, with the two new preparation intermediates as a reaction to the substrate, the C-N nucleophilic substitution reaction ofα-bromo-aromatic hetero- ethanone and substituted piperidine to offer the corresponding piperidine derivatives. In this experiment, molar ratio, base, solvent and temperature was investigated to establish the optimum reaction conditions. The 2-[4-(Benzothiazol-2-yloxy)-piperidin-1-yl]-1- thiophen-2-yl-ethanone etc 10 species double replaced piperidine kind of derivatives were obtained in yield of 73.7% under optimized condition. The structure of the target product was characterized by MS, NMR, and IR.