The yield of cyclohexanone 1,3-butanediol ketal was up to 94.0% when molar ratio of cyclohexanone to 1,3-butanediol was 1∶1.5,amount of catalyst was 2.0%,water-carrying agent was 10 mL,and reaction time was 80 mins.
n(cyclohexanone)∶ n(1,3-propanediol)=1∶ 1.2,the quantities of catalyst was(1.0 g,)toluene as water-carrying agent,reaction time was 1.5 h,the yield of product reached over(99.1%),the purity was(99.6%.)
Optimum reaction condition was obtained as follows: n(alocohol)∶n(acid)=1.2∶1,catalyst loading = 1.0 g(equivalent to 9% of reacting propionic acid),water-carrying agent 8 mL,reaction time 2.5 h.
Experimental results indicated that the optimum conditions of esterification reaction were as follows: the molar ratio of benzaldehyde and glycol and sulfaminic acid 1∶2.0∶0.082,water-carrying agent of cyclohexane 10 mL,the reaction time 75 min,and the acetal yield was up to 93.07%.
The results showed that the esterification rate was 98% in following conditions:molar ratio of acid to alcohol 1∶3.5,amount of catalyst 2.0 g(12% based on citrate acid amount),reaction temperature 100～ 120 ℃,reaction time 3 h,and water-carrying agent methylbenzene 5 mL.
Ester yield of 90.0% was obtained under the following condition: n(ethylene glycol monomethyl ether)∶n(acetic acid)∶(n(sodium) bisulfate)=1∶1.75∶0.003 62, benzene as water carrying agent, reflux and water segregation for 60 min.
Factors influencing the yield were examined by the orthogonal experiments. The optimum conditions are as follows∶(n(ethyl acetocetate))∶n(glycol) 1∶1.5,catalyst dosage(7.5 g),water carrying agent(7.5 mL),reaction under reflux condition for(3 h).
The experimental result showed that the yield of esterification was up to 91.43% under opti- mum reaction conditions as follows:the molar ratio of chloroacetic acid to anhydrous ethanol 1:1.2,the dosage of catalyst based on total reactants 3.3%,water carrying agent of 12.5 mL,reaetion time of 1.5h.
The cyclohexanone 1,3-propanediol ketal is synthesized from cyclohexanone and 1,3-propanediol in the presence of SO~(2-)_4-TiO_2/Al_2O_3 solid superacid catalyst. The effects of catalyst activating temperature,TiO_2 loading amounts,dosage of catalyst,ratio of reactants,kinds and amounts of water carrying agent on reaction were examined.
Experimental results showed that the optimal reaction conditions are: based on n-octylaldehyde 0.1 mol,the molar ratio of n(n-octylaldehyde)∶n(1,2-propanediol)=1.0∶1.1,the dosage of catalyst 1.0% of the total mass of the reactants,the amount of cyclohexane used as water carrying agent 12 mL,reaction time 3.0 h. The yield achieves 92.3%.
The yield of the ester could reach 91.9%under amount of substance ratio of maleic anhydride, ethyl alcohol and ammonium ferric sulfate dodecahydrate was 1∶4∶0.08,cyclohexane as water carrier, at 70~85℃, refluxed and water segregate for 90 min.
The results showed that the optimal conditions for synthesis of benzyl acetate were: the molar ratio of acetic acid to benzyl alcohol was 2∶1,the amount of the water carrier was 40%,the amount of the catalyst was 3.5%,and reaction time was 6 h.
The optimum conditions are follows: molar ratio of propionic acid to n-butyl alcohol is 1∶1.2, reaction time is 2.5h, weight of catalyst is 1.5g, the amount of water carrier is 10ml, The yield under the optimum conditions was up to 99.2%.
Usage of Si-W heteropoly acid as the catalyst for synthesis of fructone was studied in this short paper and the optimal reaction condition was determined involving 25.4 mL ethyl acetoacetate, 22.3 mL ethylene glycol, 20 mL benzene as water carrier, 1.5 g Si-W heteropoly acid used as catalyst and refluxing for 2 h.
Optimal reaction condition were microwave power 450 W,irradiation time 45 min,the molar ratio of ethanol to lactic acid was 2∶1,weight of catalyst was 2.0% of lactic acid mass,the amount of water carrier was 15 mL,and as a result,the yield of ethyl lactate reached up to 89.2%.
The catalysts had high activity in the esterification reaction. Thus,0 17 mol acetic acid, 0 33 mol n butanol,1 0 g catalyst and 8 mLcyclohexane(as water entrainer) reacted at the reflux temperature for 2 0 h,the conversion of acetic acid could reach 88 5%-97 1%,while under the same reaction conditions,the conversion of acetic acid was only 29 6% without the catalyst.
Excess of ethanol acted as water entrainer(water was adsorb with 3A molecular sieve),n(ethanol):n(palmitic acid)=9:l,m(eatalyst):m(palmitic acid)=0.06:l,reaction temperature was 80～ 83℃,and reaction time was 4 h.
The composite catalyst was applied to the acetalation of benzaldehyde with ethylene glycol. Thus,with n(benzaldehyde)∶n(ethylene glycol)=1∶1.8,w(catalyst)=6% of feed stock,cyclohexane as water entrainer and reacting for 1 h,benzaldehyde ethylene glycol acetal can be obtained in 82.41% yield.
With propanoic acid and ethanol as raw materials,cyclohexane as water entrainer and sodium hydrogen sulfat as catalyst,ethhyl propionate was synthesized directly under normal pressure and microwave irradiation.
With acetic acid and cyclohexanol as raw materials, cyclohexane as water entrainer and p toluenesulfonic acid as catalyst,cyclohexyl acetate was synthesized directly under normal pressure and microwave irradiation .
Standard solutions and samples (200?μL) were injected into a water carrier stream and both pH and ionic strength were automatically adjusted inside the manifold.
The on-line manifold for calcium determination is the simplest possible, because a volume of 250?μL of acid extract is injected into an ultrapure water carrier stream.
带水剂
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