Synthesis Of Pyridin-4-one And Thiazolidone Mediated By Activated Sulfoxide

Activated sulfoxide system has important application value in organic synthesis,and various types of reactions can occur,which is a hot spot for organic chemists.A variety of N-alkyl substituted pyridin-4-one and thiazolo[3,2-a]pyridin-5-one compounds were synthesized by activated sulfoxide.Pyridin-4-ones and thiazolpyridones are widely present in natural products,drug molecules and biologically active molecules,and are intermediates for the synthesis of complex natural products.Although these two types of compounds have important application value,there are still few methods for synthesizing them to date.The main contents of this paper are as follows:(1)Arylalkyl sulfoxide was activated by trifluoromethanesulfonic anhydride and reacted with 4-fluoropyridine compound,followed by hydrolyzed to obtain a plurality of N-alkyl substituted pyridin-4-one compounds.The reaction was carried out in one pot process,conditions were simple,raw materials were easily available,and excellent yield can be obtained,which provided a new method for synthesizing pyridin-4-one compounds.(2)6-fluoropyridylbenzyl sulfoxide was activated by trifluoro-methanesulfonic anhydride and reacted with disubstituted and trisubstituted olefins,and then hydrolyzed to obtain thiazolo[3,2-a]pyridin-5-one with various substituents.The reaction did not require metal participation,one-pot synthesis,raw materials were simple and easy to obtain,and the yield could reach up to 97%.The intermediate pyridinium salt of the reaction was synthesized and a possible reaction mechanism was proposed.This method provided a new idea for the synthesis of thiazolpyridone.