3-Ethyl-2-methyl-5-methylene-6,7-dihydroindol-4(5H)-one

Abstract

The title compound, C12H15NO, a degradation product of molindone hydrochloride, was prepared by the reaction of molindone with methyl iodide and subsequent reaction of the resulting quaternary ammonium salt with 2N aqueous sodium hydroxide. The newly formed double bond is exocyclic in nature and the carbonyl group is conjugated with the π-electrons of the pyrrole ring. The six-membered ring is in the half-chair conformation. The H atom attached to the N atom is involved in an intermolecular hydrogen bond with the O atom of a screw-related molecule, thus forming a continuous chain.