PROBLEM TO BE SOLVED: To provide a crystalline form of N-{(3R*,4S*)-3-hydroxy-6-methoxy-2,2-dimethyl-4-(phenetylamino)chroman-7-yl}methanesulfonamide which has antiarrhythmic action and is useful as a pharmaceutical raw material and to provide an industrial production method thereof which is stable and safe.SOLUTION: There are provided: a method for producing N-{(3R*,4S*)-3-hydroxy-6-methoxy-2,2-dimethyl-4-(phenetylamino)chroman-7-yl}methanesulfonamide which comprises a step of reacting a compound represented by the following formula with hydrochloric acid in an ester-alcohol mixed solvent or a nitrile solvent to crystallize and a crystalline form obtained by the production method.COPYRIGHT: (C)2015,JPO&INPIT【課題】抗不整脈作用を有し、医薬品原料として有用なN-{(3R*,4S*)-3-ヒドロキシ-6-メトキシ-2,2-ジメチル-4-(フェネチルアミノ)クロマン-7-イル}メタンスルホンアミドの新規結晶形態、及びその安定かつ安全な工業的製造方法の提供。【解決手段】下記式の化合物をエステル-アルコール混合溶媒又はニトリル溶媒中、塩酸と作用させ、結晶化させる工程を含むN-{(3R*,4S*)-3-ヒドロキシ-6-メトキシ-2,2-ジメチル-4-(フェネチルアミノ)クロマン-7-イル}メタンスルホンアミドの製造方法、及び前記製造方法で得られる結晶形態。【選択図】図1
