Process for production of carbostyril compound

摘要

The invention provides an improved process for preparing a carbostyril compound (1) or a salt thereof that is useful as a medicament, which makes it possible to prepare it more safely and efficiently. In more detail, the invention provides an improved process for preparing the carbostyril compound (1) by heating the compound (4) with a high boiling solvent in hydrochloric acid under reflux to give the compound (5) safely; and then acylating the compound (5).