The reactions of acetylenic esters with N-substituted indoles

Abstract

Reaction of an arylpropiolic ester with indol-1-ylacetamide and ethyl indol-1-ylacetate in the presence of sodium ethoxide yielded 4-aryl-3-(indol-1-yl)pyridine-2,6(1H,3H)-diones and ethyl arylpropioloyl- (indol-1-yl)acetates respectively. Reaction of arylpropiolic esters with 1-acetylindole in the presence of sodium ethoxide at 0º yielded two products, 5-aryl-1-(indol-1-yl)pent-4-yne-1,3-dione and ethyl 8-(indol-1-yl)cinnamates, as a result of Claisen and Michael reactions respectively. These products were identified on the basis of spectral and analytical data.