Synthesis
The general procedure for the synthesis of 5-fluoro-3,4-dihydronaphthalen-1(2H)-one from 4-(2-fluorophenyl)butyric acid was as follows: 0.15 g of 4-(2-fluorophenyl)butyric acid was added to a round-bottomed flask, which was dissolved in 20 mL of dichloromethane (DCM) and the solution was cooled to 0 °C. Subsequently, 0.15 mL of oxalyl chloride was slowly added and 1 drop of N,N-dimethylformamide (DMF) was added as a catalyst. A drying tube was installed and the reaction mixture was kept stirred at 0 °C for 2 hours. Upon completion of the reaction, 0.121 g of anhydrous aluminum chloride was added and the reaction mixture was slowly warmed to room temperature and stirring was continued overnight. The reaction mixture was carefully poured into ice water and extracted three times with dichloromethane. The organic layers were combined and washed sequentially with 0.5 M sodium hydroxide solution and saturated brine. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure, and the resulting crude product was purified by column chromatography (eluent: 20% ethyl acetate/hexane) to afford 0.07 g (53% yield) of the target compound 5-fluoro-3,4-dihydronaphthalen-1(2H)-one (32). In addition, 5-fluoro-1,2,3,4-tetrahydronaphthalen-1-amine (34) was synthesized.
References
[1] Angewandte Chemie - International Edition, 2013, vol. 52, # 35, p. 9266 - 9270
[2] Angew. Chem., 2013, vol. 125, # 35, p. 9436 - 9440
[3] Chemistry - A European Journal, 2015, vol. 21, # 14, p. 5561 - 5583
[4] Patent: US2008/119496, 2008, A1. Location in patent: Page/Page column 12
[5] Patent: EP2128154, 2009, A1. Location in patent: Page/Page column 33
