Beckmann Fission of Some Fused Cyclobutanones: A New Entry into Indole-2-Acetonitriles and Benzo[b]thiophene-2-acetonitrile

Abstract

Fused cyclobutanone derivatives have been utilized as intermediates in a variety of synthetic schemes.¹⁾ We are investigating the synthesis and ring opening reactions of cyclobutanones fused to indoles, benzo[b]furans, and benzo[b]-thiophenes, in part with the hope of discovering a novel method for introduction of two carbon atoms to such heteroaromatic systems. In this communication the synthesis and Beckmann fission²⁾ of the cyclobutanone derivatives fused to 1-benzoyl-indoles and benzo[b]thiophene are described. This provides a new entry into indole-2-acetonitriles³⁾ and benzo[b]thiophene-2-acetonitrile.⁴⁾