Trimethyl phosphite mediated simple synthesis of coumarins and azachromenes through the reaction of phenols and dimethyl acetlendicarboxylate

Allahdad Shababi, Reza Shababi

Abstract

Protonation of the reactive intermediates produced in the reaction between Trimethyl Phosphite and dimethyl acetylenedicarboxylate by resorcinol 5- methylresorcinol 2,5 -dihyroxyasetophenone, 4 - chlro - 2 -methvlphenol, 2 - hydroxypyridine, or 4 - hydroxypyridine - leads tovinylphosphoniumsalts, which undergo michail addition with the conjugate basi of the OH-acid to produce functionalized 2-oxo-2H-chromenes (coumarins) and azachromenes in good yields.