NEW METHOD FOR PRODUCING RAMOSETRON OR SALT THEREOF

PROBLEM TO BE SOLVED: To provide a new method for producing ramosetron or a salt thereof, useful as a pharmaceutical, in particular as a therapeutic and/or preventive agent for digestive symptoms resulting from administration of an anti-malignant tumor agent, diarrheal-type irritable bowel syndrome, diarrheal symptoms of irritable bowel syndrome, etc. SOLUTION: Ramosetron or the salt thereof can be produced by reacting the compound of formula (I) [wherein X is a halogen] or a salt thereof with 1-methyl-1H-indole in the presence of a Lewis acid selected from the group consisting of a lower alkylaluminum dihalide, a di-lower alkyl aluminum halide, a tri-lower alkylaluminum and a lower alkylaluminum sesquihalide. COPYRIGHT: (C)2010,JPO&INPIT