A Facial Protocol for the Synthesis of Benzofuran Derivatives by the Reaction of o-Hydroxy Aryl Ketone, Amine and Chloroacetyl Chloride

Abstract

A facile and effective method has been developed for the synthesis of a novel series of benzofuran derivatives via N-acylation, O-alkylation and intramolecular condensation reactions, starting from readily available substituted o-hydroxy aryl ketone, and chloroacetyl arylamides. This metal-free transition process is characterized by mild reaction conditions, atom economy, short reaction time and a high yield with a decreased amount of by-products.

New method for the acylation of benzofurans toward the synthesis of 6H-indeno[2,1-b]benzofuran-6-ones and 2,2-bibenzofurans

“…The base-catalyzed intermolecular or intramolecular condensation reactions to construct a fused furan ring to form 2-substituted benzofuran derivatives is the most common synthetic method (Scheme 1a). 10,11 2-Acylbenzofurans can also be obtained by Lewis acid catalyzed acylation of benzofurans using acid anhydrides or acyl chlorides as acylating agents (Scheme 1b). [12][13][14][15] The trifluoroacetic anhydride (TFAA)-mediated acylation 16 using carboxylic acids as the acylating agent have been applied to arenes 17 and heteroarenes including thiophenes, 18 benzothiophenes, 19 pyrroles, 20 and carbazoles.…”