105640-07-1

82240-03-7

105640-07-1

General procedure: 56.1 g of 4-(4-benzyloxyphenyl)cyclohexanone, 336.6 mL of tetrahydrofuran and 2.8 g of 5% Pd/C catalyst were sequentially added to a 500 mL three-neck flask. The atmosphere in the flask was replaced three times with hydrogen and the hydrogenation reaction was subsequently carried out under hydrogen atmosphere. The reaction system was heated to 40-45 °C in a water bath and maintained at this temperature until completion of the reaction (reaction endpoint determination criterion: 4-(4-benzyloxyphenyl)cyclohexanone residue less than 1%, specifically 0.5687%). Upon completion of the reaction, the heating and hydrogen supply were stopped. Post-treatment steps: the reaction mixture was filtered and the filter cake was washed twice with tetrahydrofuran, 5 mL each time. the filtrates were combined and concentrated under reduced pressure at 35-45 °C and -0.08 MPa to -0.09 MPa until no fraction flowed out, yielding a white solid. To this solid was added 195 mL of ethanol and heated to reflux (60-65 °C) for 1-2 h until completely dissolved and clarified. The solution was then cooled to -25 to -15°C and left to crystallize for 8 hours. The crystals were collected by filtration and washed twice with ethanol, 5 mL each time.The filter cake was dried under reduced pressure at 45-55 °C, -0.08 MPa to -0.09 MPa for 10 h to give 32 g of white to off-white powdery solid, i.e., the target product 4-(4-hydroxyphenyl)cyclohexanone.