Synthesis of 1,3-disubstituted-pyrrolo[2,1-a]isoquinoline-2-carboxylic acids, esters and amides

Abstract

A number of 1,3-disubstituted pyrrolo [2,1-a] isoquinoline-2-carboxylic esters have been prepared using a variety of independent routes. The corresponding acids and a range of amides were subsequently synthesised. The primary amides were found to differ significantly from those reported to arise from the reaction between the anion of an isoquinoline Reissert compound and an α,β-unsaturated nitrile. Re-investigation has established that the latter reaction does not produce primary amides. The true nature of the products as 2-acyl-3-aminopyrrolo[2,1-a]isoquinolines was established using X-ray crystallography.