Synthesis of 3-[(coumarinyl)carbonyl]-3a,8b-dihyroindeno[1,2-b]pyrrole-4(1H)-ones and their conversion to coumarin bearing spiro[isobenzofuran-1,2′-pyrrole] moiety compounds via oxidative cleavage reaction

Abstract

New coumarin derivatives bearing an indenopyrrole moiety were prepared by the reaction of salicylaldehyde, 4-hydroxy-6-methyl-2H-pyran-2-one, benzylamine and ninhydrin in the presence of triethylamine as a basic catalyst; the as mentioned compounds lead to coumarin bearing spiro[isobenzofuran-1,2′-pyrrole] moiety compounds via an oxidative cleavage reaction by periodic acid. Ease of handling, easy purification and moderate to good yields are attractive features of the present method. The products were also characterized using IR, mass, elemental analyses, ¹H NMR, ¹³C NMR and X-ray crystallography.