Ethanol → N-(3-Fluoro-4-methyl-5,6,7,8-tetrahydro-1-naphthyl)acetamide

The compound obtained in (4) above (1.35 gm) was dissolved into 5 ml of ethanol and 15 ml of THF. To the solution was added 114 mg of sodium borohydride while stirring at room temperature. After stirring for 20 minutes, the reaction mixture was concentrated. To the concentrate were added 25 ml of toluene and 840 mg of p-TsOH, followed by heating under reflux for 30 minutes. Upon the addition of 100 ml of ethyl acetate, the reaction product was washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was evaporated and the residue was dissolved into 20 ml of ethyl acetate and catalytically hydrogenated with the addition of 400 mg of platinum oxide for 4 hours. The catalyst was removed, the filtrate was concentrated, and 10 ml of dichloromethane was added to the concentrate. After the further addition of 1.2 ml of triethylamine and 0.81 ml of acetic anhydride, the mixture was stirred for 40 minutes. The reaction product was diluted with 50 ml of chloroform, washed with dilute hydrochloric acid, saturated sodium bicarbonate and saturated brine in this order, and dried over anhydrous sodium sulfate. The solvent was evaporated to obtain 1.23 gm of the title compound.