252061-66-8

22246-66-8

252061-66-8

General procedure for the synthesis of 5-hydroxy-isoindolin-1-one from 5-methoxy-2,3-dihydroisoindol-1-one: To a suspension of 5-methoxy-2,3-dihydroisoindol-1-one (5.65 g, 34.6 mmol) in dichloromethane (300 mL) was added slowly and dropwise over a period of 20 min boron tribromide (25.1 g, 100 mmol, 1.0 M dichloromethane solution). After the dropwise addition, the reaction mixture was gradually warmed to room temperature and stirring was continued for 3 hours. Subsequently, the reaction was quenched with methanol (100 mL) at 0 °C and stirring was continued for 3 hours. Upon completion of the reaction, the reaction solution was concentrated, water (500 mL) was added, heated to 60 °C and kept for 1 hour. After cooling, the solid product 5-hydroxy-2,3-dihydroisoindol-1-one was obtained by filtration (4.10 g, 79% yield, CAS No. 252061-66-8). Mass spectrometry (electrospray ionization): m/z 150.0 [M+H]+ (calculated value: 149.0).