PROBLEM TO BE SOLVED: To provide a method for producing β crystals of indoline compounds, preferably a method for producing β crystals that does not use seed crystals of β type crystals and prevents the transfer of crystal forms even when in a slurry state.SOLUTION: An indoline compound represented by formula (1) is crystallized using at least one solvent selected from an ester solvent represented by formula (2) and an ether solvent represented by formula (3). R CO2R1 (2) (R is a C1-C4 alkyl group R1 is a C3-C6 branched alkyl group). ROR1 (3)SELECTED DRAWING: NoneCOPYRIGHT: (C)2018,JPO&INPIT【課題】インドリン化合物のβ型結晶の製造方法、好ましくはβ型結晶の種結晶を使用せず、スラリー状態におかれても結晶型の転移を起こさないβ型結晶の製造方法の提供。【解決手段】式(1)に示されるインドリン化合物を、式(2)で示されるエステル溶媒、及び式(3)で示されるエーテル溶媒から選ばれる少なくとも1種の溶媒を用いて晶析化させる。RCO2R1...(2)(RはC1~C4のアルキル基;R1はC3~C6の分岐状のアルキル基)ROR1...(3)【選択図】なし
