Study On Synthesis Of Isooctyl Mercaptoacetate

In this thesis, isooctyl choloroacetate was synthesized by choloroacetic acid and isooctanol with solid acid as catalyst. SO₄^2-/TiO₂, SO₄^2-/ZrO₂, macroporous sulfoacid ion exchange resin-AlCl3 suepr acid and heteropolyacid supported on actived carbon were prepared. The effects of factors as varieties of catalyst, the amount of moler ratio of isooctanol to choloroacetic acid, catalyst amount, water-entrainer amount and reaction time on the yield of ester were discussed. The results showed that the SO₄^2-/TiO₂ was a better catalyst and the optimum conditions should be that based 0.15mol choloroacetic acid, the moler ratio of isooctanol to choloroacetic acid was 1.2:1.0, the amount of catalyst was 1.2% of the total mass of reactants, the amount of cyclohexane was 10ml, the reaction time was 2.5h. The yield of estification reached 98.52% under such conditions. The catalyst SO₄^2-/TiO₂/silica-gel was prepared and was characterized by SEM. All of the fresh and used catalysts have showed the high acitivity. They are very convenient to recycle.The technology research of production of isooctyl thioglycolate by isooctyl choloroacetate and sodium hydrosulfide with phase transfer catalyst have been carried out. The effects of many factors, such as the amount of catalyst, the concerntration of NaSH, the moler ratio of isooctyl choloroacetate to sodium hydrosulfide, the volume of solvent and reaction temperature were studied preliminary. And the optimal synthesis conditions were detailed as: based 0.08mol isooctyl choloroacetate, the moler ratio of sodium hydrosulfide to isooctyl choloroacetate was 1.3:1.0, the amount of catalyst was 0.8% of the total mass of reactants, the volume of solvent was 25mL, the reaction temperature was 20-25℃. Under these conditions, the yield of isooctyl thioglycolate was more than 80%.The synthesis of isooctyl thioglycolate by sodium sulfide as originally reactant was studied. The main factors influencing the reaction were also investiged, such as the iniatially concerntration of Na₂S₂, solvent, the moler ratio of reactants, reaction time, the amount of reducing agent and so on. The proper synthesis condition details were obtained as follows : based 0.08mol isooctyl choloroacetate, the moler ratio of sodium sulfide to isooctyl choloroacetate was 1.25:1.0, w(Na₂S₂)%=15%, n (Zn): n (isooctyl choloroacetate) =1.1:1.0, the reducing time was 2h. And the yield of our profuct was high as 88% in the conditions.