A new approach to 4-(2-aminoethyl)indoles via Claisen ortho-amide rearrangement of 3-hydroxy-2-methoxyindolines
Abstract
Reaction of 3-hydroxy-2-methoxyindoline (4) with the amide acetal (5) gives 4-carbamoylmethyl-indoline (7) and -indole (8), which are converted into 4-(2-aminoethyl)indole (10) by treatment of the indoline (7) with hydrogen chloride followed by sodium hydroxide to form the indole (8), and then by reduction of the indole (8) with lithium aluminium hydride.