Verfahren zur Herstellung von 3-Indolylsäuren

摘要

preparation of 3-indolyl acetic acid derivatives of formula (I):- where R = methoxy or dimethylamino. The method gives a more convenient synthetic procedure than that described in the US. Patent 3,161,654. To 250 ml. of a dioxan solution containing 0.1 equivalent of 1-p-chlorobenzoyl-2-methyl-5-methoxyindole and a small quantity of copper powder, a solution of 0.11 equivalents of diazoacetic acid in 100 ml. water was added with stirring. The mixture was kept at 25-30 deg.C. for 5 hrs. and then concentrated in vacuo. The residue was extracted with ether, filtered and concentrated in vacuo to a solid residue. alpha(-1-p-chloro-benzoyl-2-methyl-5-methoxyindolyl-(3)) acetic acid.