Abstract: The present invention provides a novel industrially or economically preferable process for production of a hydrogen halogenide salt of a Donepezil derivative having an excellent pharmacological action as medicament, namely, reaction of 1-indanone derivative with carbonate ester to obtain 2-alkoxycarbonyl-1-indanone derivative, followed by reaction with halogenated (4-pyridyl)methyl or a salt thereof and decarboxylation successively to obtain 2-(4-pyridyl)methyl-1-indanone derivative, then reaction with halogenated benzyl to obtain quaternary ammonium salt, then reduction, and synthetic intermediates thereof. (Wherein R1 represents a hydrogen atom or lower alkoxy; n represents an integer of 1 to 4; R2 represents lower alkyl group; and X represents a halogen atom.