4-(3-chlorophenyl)butanoic Acid → 6-Chloro-1-tetralone

Participants

Reaction Steps

A mixture of 35.72 g of the product from Step B and 50 mL of thionyl chloride was heated at reflux for 2 hours and then stirred at room temperature for 18 h. After this time, thionyl chloride was removed at reduced pressure and the product was dissolved in carbon tetrachloride and concentrated at reduced pressure. The residue was dissolved in 150 mL of dichloroethane cooled to 0° C. and 28 g of aluminum chloride was added portionwise over about 1 hr in approximately 3 g portions. After stirring for 3 h, the reaction was poured over a mixture of ice/1N HCl and extracted three times with methylene chloride. The organic extracts were dried over magnesium sulfate and concentrated to approximately 30 g of a brown oil. Chromatography on silica gel with 10% ethyl acetate/hexane afforded 17.83 g of 6-chloro-3,4-dihydro-1(2H)-naphthalenone as a brown oil. 1H NMR was consistent with the structure.

Provenance & Evidence