(S) formula (i) - N - methyl - 3 - (1 - the naphthyloxy) - 3 - (2 - chieniru) as for propylamine hydrochloride, as for the deyurokisechin suspensoid in the blend of the aprotic solvent and the protic solvent, under decreasing the specific volume of the protic solvent, it is crystallized with the kind of manner which is agitated at the temperature which rose simultaneously.式(I)の(S)‐N‐メチル‐3‐(1‐ナフチルオキシ)‐3‐(2‐チエニル)プロピルアミン塩酸塩は、非プロトン性溶媒とプロトン性溶媒の混合物中デュロキセチン懸濁液は、プロトン性溶媒の体積比の減少下で、同時に上昇した温度で撹拌されるような方法で、結晶化される。