6968-35-0

491-37-2

6968-35-0

General procedure for the synthesis of 7-hydroxy-1-indanone from 2,3-dihydrochromen-4-one: 37.0 g (278 mmol) of aluminum chloride was mixed with 3.70 g (61.3 mmol) of sodium chloride, and the mixture was heated at 150 °C until completely dissolved. Subsequently, 6.40 g (43.2 mmol) of commercially available 2,3-dihydro-4H-chromen-4-one (preheated to 50 °C to dissolve) was added and the reaction mixture was stirred at 200 °C for 20 minutes. After completion of the reaction, the reaction mixture was cooled to a gelatinous consistency, pre-prepared ice-cold hydrochloric acid (200 ml made by mixing 100 ml of concentrated hydrochloric acid with ice) was slowly added and stirred continuously for 30 minutes. The reaction mixture was extracted with dichloromethane and the organic layer was separated. The aqueous layer was filtered and the filtrate was again extracted with dichloromethane. All organic layers were combined, washed sequentially with water and brine and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure and the resulting crude product was purified by silica gel column chromatography (Wakogel C-100, eluent hexane-ethyl acetate gradient) to give 4.82 g (32.6 mmol, 75.2% yield) of the target product 7-hydroxy-1-indanone.