Studies of as-Triazine Derivatives. XV. Intramolecular Reverse-Election Demand Diels-Alder Reaction of 1,2,4-Triazine Derivatives

Abstract

5,6-Diphenyl-1,2,4-triazine-3-carboxylic acid esters which have acetylenic function in the alcoholic moiety of the ester group were converted to the pyridine derivatives condensed with lactone ring by means of intramolecular reverse electron-demand Diels-Alder reaction.This type ring-transformation was applicable to the corresponding 3.5-diphenyl-1.2.4triarine-6-carboxylic acid esters.According to the similar manner, b e n z o f u r o [ 2 , 3 -b l p y r i d i n e s .benzofuro[2,3-clpyridines. and b e n z o f u r o [ 2 , 3 -d l p y r i m i d i n e s were synthesized in satisfactory