乙酸肉桂酯的合成.ppt
Synthesis of cinnamyl acetate（乙酸肉桂酯）by solidliquid phase transfer catalysis:Kinetic study with a batch reactor Catalysis Communications 10(2009)16381642化学与化学工程学院陈小玲,Contents,Conclusions,1.Introduction,PTC,phase transfer catalysis,1.Introduction,eliminates the need of using aqueous phase thus eliminates the separation problems and easy recovery of the catalyst,enhances the productselectivity by avoiding the side reactions,lower selectivityand other side reactions,synthesis of fine and specialty chemicals,separation and purifying the final product,Compared with L-L PTC and L-S PTC,L-S PTC,the carboxylic acids shows less reactivity,omega phase”enhance the solubilization of the solid and formationof the catalytic intermediate,1.Introduction,we focus our efforts on studying the kinetics and factors affecting the synthesis of cinnamyl acetate（乙酸肉桂酯）from cinnamyl bromide（肉桂酸溴）and sodium acetate（乙酸钠）by SL PTC.,1.Introduction,2.Experimental,sodium acetate(0.025 mol)，cinnamyl bromide(0.02 mol)，n-dodecane,add chlorobenzene to 50 mL and the temperature was raised to 90C with constant stirring,Product,add a requiredamount of phase transfer catalyst when the temperature reached 90C,At preset times,thestirrer was turne off temporarily,0.5 ml of organic solution was pipetted out,analyzed on a gas chromatograph using SE-30 Column.,3.Results discussion,type of catalyst,speed of agitation,reaction temperature,water addition,size of sodium acetate,catalyst loading,concentration of reactant,In order to optimize the reaction conditions,the esterification reaction was carried out by varying factors as follow:,3.Results discussion,3.1 Effect of agitation speed,The interfacial mass transfer resistance between the solid surface and organicphase is negligible when the agitation speed is above 600 rpm.In this context,agitation speed was fixed at 600 rpm for all furtherexperiments.,3.Results discussion,3.2 Effect of alkyl chain length of the catalyst,Hence TBAB is chosen as the phase transfer catalyst in the following studies.,3.Results discussion,3.3 effect of reaction temperature,Although a high temperature usually favors the side reactions,no side products were found at 95 C in this study.,3.Results discussion,3.4 Effect of catalyst loading,Since reasonable conversions are observed at the catalyst loading of 1.6 g,the further experiments are carried out at the catalyst loading of 1.6 g.,3.Results discussion,3.5 Effect of mole ratio,The conversion of cinnamylbromide increased with the increase of mole ratio of cinnamyl bromide to sodium acetate from 1:1 to 1:1.5 and remained almost constant thereafter.,3.Results discussion,3.6 Effect of water addition,The optimal usage of water in the present study was observed to be 4 ml.,3.Results discussion,3.7 Effect of patical size of sodium acetate,Low reactivity of the sodium acetate granules may be attributed to their low surface area and mass transfer limitations.,3.Results discussion,rate expression,(1),3.Results discussion,rate expression,（2）,3.Results discussion,rate expression,k=kCc,（3),4.Conclusions,1、The solidliquid phase transfer catalysis was successfully employed for the synthesis of cinnamyl acetate from the esterification of sodium acetate with cinnamyl bromide by using TBAB as the catalyst.2、Using a moderate amount(1.6 g)of tetran-butyl ammonium bromide as the catalyst at 95 C.3、The solidliquid interfacial mass transfer resistance is negligible at agitation speed above 600 rpm.4、The catalyst with longer alkyl chain length gives better performance,however,it will more easily dissolved in the organic phase and hence is more difficult to be removed and reused after the reaction.5、Adding 18 ml of water improved the reactivity of the catalyst.6、The reaction results obtained at 8095 C well fitted into the pseudo-first order rateequation.The activation energy was found to be 11.9 kcal mol-1.7、Its value of rate constant at 90 C was 3.3*10-5 L g-1 min-1.,References,1 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