2-甲基-6-丙酰基萘液相氧化制备2,6-萘二甲酸研究

Preparation of 2,6-naphthalene dicarboxylic acid from 2-methyl-6-propionyl naphthalene via liquid phase oxidation

以2-甲基-6-丙酰基萘为原料,在Co-Mn-Br催化体系中液相氧化制备2,6-萘二甲酸,考察了催化剂质量分数、助催化剂比例、反应温度、反应压力、原料与溶剂质量比、反应时间、空气流量等因素对反应的影响。利用HPLC、IR、^(1)HNMR、pH计对产物进行定性分析。得出制备2,6-萘二甲酸的适宜反应条件为:温度为190℃、时间为45 min、m(Co)∶m(Mn)∶m(Br)=1∶2∶5、m(MPN)∶m(HAc)=1∶15、压力为2.0 MPa、空气流量为1.4 L/min。在此条件下,2,6-萘二甲酸收率和纯度分别为83.47%和91.94%,可达到减少重结晶等提纯步骤、简化工艺流程、降低氧化反应原料成本。

2,6-Naphthalene dicarboxylic acid is prepared from 2-methyl-6-propionyl naphthalene via liquid-phase oxidation in the Co-Mn-Br catalytic system.The effects of the mass fraction of catalyst,the ratio of cocatalyst,reaction temperature,reaction pressure,the mass ratio of raw materials to solvent,reaction time and air flow rate on the reaction are investigated.The products are qualitatively analyzed by means of high performance liquid chromatograph,infrared spectrometer,hydrogen nuclear magnetic resonance spectrometer and acid value determination.According to the experimental results,the optimum conditions for the preparation of 2,6-naphthalene dicarboxylic acid are as follows:reaction temperature is 190℃,reaction time is 45 min,m(Co)/m(Mn)/m(Br)=1/2/5,m(MPN)/m(HAc)=1/15,reaction pressure is 2.0 MPa,and air flow is 1.4 L·min^(-1).Under these conditions,the yield and purity of 2,6-naphthalene dicarboxylic acid are 83.47%and 91.94%,respectively,which can eliminate the recrystallization step,simplify the process route,and reduce the demand for raw materials in the oxidation reaction.