Synthesis and NMR Studies of Novel 2-Eteroarylbenzofuran Derivatives

The benzofuran scaffold is ubiquitous in the area of pharmacologically active agents and isolated natural products. Natural products possessing the 2-substituted moiety exhibit a broad range of pharmacological activities such as antimicrobial, anti-inflammatory, antifungal, antipsychotic, antilipidemic, analgesic, cytotoxic and central nervous system stimulant. Also, benzofuran nucleus has been recently described as a good scaffold for designing potent and relatively non-selective MAOIs. The synthesis and identification of novel 2-eteroarylbenzofuran derivatives with electron-donating and electron-withdrawing substituents are reported in this work. The key step for the formation of the benzofuran moiety was achieved by an intramolecular Wittig reaction between ortho-hydroxybenzyltriphosphonium salts and the appropriate aroyl chlorides. Their complete structural characterization was performed using one-dimensional and two- dimensional resonance techniques. The acquired data constitute a valuable database for the unambiguous identification of eteroarylbenzofuran library developed with the aim of our medicinal chemistry program.