Preparation Of Trans-1,2-cyclohexanediol

In this work, we used epoxycyclohexane which was produced in our laborary and hydrogen peroxide and cyclohexene which were rich in Henan Province as the main raw materials to carry out the experiment on preparing of tans-1,2-cyclohexanediol. The main works and results were as follows:A series of solid acid catalysts such as SO₄^2-/TiO₂, SO₄^2-/ZrO₂,H₃PW₁₂O₄₀/SiO₂,H₃PW₁₂O₄₀/Cand PS-C were prepared. These catalysts and D72. macroporous strong acid cation exchange resin were applied to hydrolysis of preparing trans-1,2-cyclohexanediol from epoxycyclohexane. The results showed that the activity of PS-C was higher than others. And PS-C was characterized by FT-IR. It was investigated that effects of the molar ratio of water to 1,2-epoxycyclohexane, the amount of catalyst, the reaction temperature and reaction time on the product yield, and the optimum reaction conditions were obtained. Those were as follows(based on 0.1 mol epoxycyclohexane): n(H₂O):n(C₆H₁₀O)=40:1, mass of catalyst in reaction was 2.4%, reaction temperature was 70℃and reaction time was 100 min. Under the optimal conditions, the total yield of final product was above 93%. The catalyst could be resued for 5 times, the catalytic activity of the ammonium salt is still excellent and no obvious decrease in selectivity.The solubilities of trans-1,2-cyclohexanediol in pyridine, acetonitrile, DMSO, DMF, absolute alcohol, 1,2-dichloroethane, trichloromethane and ethyl acetate were measured. The results showed that ethyl acetate as nonaqueous solvent to separate trans-1,2-cyclohexanediol and 1,2-dichloroethane as recrystallization to purify trans-1,2-cyclohexanediol.A series of catalysts such as D72 macroporous strong acid cation exchange resin, 732 cation exchange resin, Nafion117, silicon oxide-nafion composite membranes via in-site synthesis and silicon oxide/nafion composite membranes via sol-gel were applied tentatively to preparation of trans-1,2-cyclohexanediol from cyclohexene and hydrogenperoxide. It showed that Nafion117 and silicon oxide-nafion composite membranes had catalytic ability in certain extent. The reaction conditions were as follows: mass of catalyst in reaction was 1.0g, n(H₂O₂):n(C₆H₁₀)=2:1 (based on 0.05mol cyclohexene), reaction temperature was 70℃and reaction time was 20 h. Under these conditions, the conversion of reactant was above 98%, and the total yield of final product was about 40%.