Pathways of ion–molecular interactions of nucleogenic phenyl cations with the nucleophilic centers of picolines

Nadezhda E Shchepina,Scott B Lewis,Sergey N Shurov,Gennady A Badun,Viktor V Avrorin,Nikolay A Bumagin

doi:10.1186/2191-2858-2-14

Abstract

BackgroundThe nuclear-chemical method brought unique opportunity for synthesis of unknown and hardly available organic compounds. Presence of tritium labeling allows one-step preparation of radioactive markers for the investigation of chemical and biological processes.MethodsThe ion–molecular reactions of nucleogenic phenyl cations with 4-picoline have been carried out. The phenyl cations were generated by spontaneous tritium β-decay within the tritium-labeled benzene. Both additions to the nitrogen and substitutions about the aromatic ring were able to be studied simultaneously.ResultsUnusual substitutions on both the α- and β-positions of the ring system have been revealed.ConclusionBy unknown direct phenylation of nitrogen atom tritium-labeled N-phenylpicolinium derivatives, perspective biological markers have been synthesized.

Highlights

The nuclear-chemical method brought unique opportunity for synthesis of unknown and hardly available organic compounds
Since by the classical methods of chemistry N-phenylpicolinium derivatives could not be prepared by phenylation reaction [18,19] and simultaneously syntheses of such compounds with the fixed tritium label are hardly available; our special interest was focused on prolongation of nuclear-chemical method on methyl-substituted pyridines and detail investigation of the pathways of ion–molecular interactions of nucleogenic phenyl cations with the 4-picoline nucleophilic centers
Free phenyl cations generated by tritium β-decay in pditritiated benzene immediately attack the existed nucleophilic centers of the picoline molecule

Summary

Background

The pyridine ring itself is a part of many natural and synthetically prepared pharmaceuticals [1,2]. Methyl-substituted pyridines, i.e., picolines, are not the exception in the list of important biologically active substances [5]. The observed increase of biological activity with the introduction of methyl group into the heterocyclic pyridine ring inspires synthetic chemists to find new methods for the preparation of derivatives with picoline fragment [6,7,8,9,10,11], and biologists for the detail investigations of biological mechanisms with the use of tritium markers [12,13,14]. Presence of tritium labeling allows one-step preparation of radioactive markers for the investigation of chemical and biological processes

Methods

Results and discussion

Conclusions