Synthesis of 9-Fluorenol: A 5-g sample of 9-fluorenone is dissolved in 30 mL of warm ethanol in a 100-mL beaker. To this solution is added, dropwise, 10 mL of a reducing reagent, freshly prepared, which consists of 200 mg sodium methoxide,10 mL methanol, and 0.4 g sodium borohydride.This solution is allowed to stand undisturbed for 10-20 min. A color change is observed as the reaction proceeds from the yellow 9-fluorenone to the white 9-fluorenol.The product is precipitated by the addition of 50 mL of water and neutralized with 0.1 M HCl, vacuum filtered, and washed with cold water to remove any residual inorganic salt formed by the excess of the sodium borohydride reagent and hydrochloric acid.The dried crude product is sufficiently pure for characterization by melting point, infrared spectra,and NMR.The crude product melting point is 153°C, with a product yield of 95-100%.
A Synthesis of 9-Fluorenol: Sodium Borohydride Reduction of 9-Fluorenone