Novel heterocyclic compounds from 2-carboxy-6-methoxybenzofuran-3-acetic acid anhydride

Abstract

2-Carboxy-6-methoxybenzofuran-3-acetic acid anhydride is utilised for the synthesis of novel polycyclic heteroaromatic compounds in which the benzofuran ring is fused or bound to pyrido [1,4]benzothiazine, thiazole, pyridine, pyrazolopyridine, pyrazole, pyrano-pyridine, and pyrazolo [1,5-a]pyrido[3,2-e]pyrimidines using versatile reaction strategies.

Waste-Free Synthesis of Condensed Heterocyclic Compounds by Rhodium-Catalyzed Oxidative Coupling of Substituted Arene or Heteroarene Carboxylic Acids with Alkynes

“…It has also been found that the present procedure is applicable to the synthesis of not only isocoumarins but also their heteroaryl analogs . Thus, treatment of 1-methyl-1 H -indole-2-carboxylic acid ( 9a ) with 2a under conditions A′ (similar to conditions A in Table but in DMF) for 2 h gave 9-methyl-3,4-diphenylpyrano[3,4- b ]indol-1(9 H )-one ( 10a ) in 96% yield (entry 1 in Table ).…”