Acid-addition salts of optically active piperidine compound and process for producing the same

A process for preparing a benzenesulfonic acid salt or a benzoic acid salt of the optically active piperidine compound represented by formula (I)

• which comprises reacting (±)-4-[(4-chlorophenyl)(2-pyridyl)methoxy]-piperidine with an optically active propionic acid compound represented by the formula (VII):
• wherein Y represents a hydrogen atom or a halogen atom;
• Z represents a lower alkoxy group;
• and * represents an asymmetric carbon, or an optically active N-acyl-amino acid;
• separating and collecting a less soluble diastereomeric salt by utilizing the difference in solubilities of the formed two kinds of diastereomeric salts;
• decomposing the resulting salt;
• reacting the resulting (S)-4-[4-chlorophenyl)(2- pyridyl)methoxy]piperidine with an ester represented by the formula (V):
• wherein R represents a lower alkyl group, and W represents a leaving group such as a halogen atom and a reactive ester group,
• to obtain (S)-4-[(4-chlorophenyl)(2-pyridyl)methoxy]piperidino] butanoic acid ester represented by the formula (VI):
• wherein R and * have the same meaning as defined above;
• hydrolyzing the resulting compound;
• and reacting the hydrolyzed compound with benzenesulfonic acid or benzoic acid to form a salt.