Study On The Preparation Of 2-methyl-6-Acylnaphthalene By Acylation Of 2-Methylnaphthalene In A Microchannel Reactor

2-Methyl-6-acylnaphthalene is an important chemical raw material for the synthesis of 2,6-naphthalene dicarboxylic acid.Currently,the preparation methods using traditional batch reactions have some disadvantage,such as low reaction efficiency,complex operation,consume many catalysts,and will pollute the environment.The microchannel reactor can accurately control the ratio of the reactants and the reaction time,and it can also be rapidly released the reaction heat and maintain a certain reaction temperature.Therefore,it is very important to study the acylation of 2-methylnaphthalene?2-MN?in a microchannel reactor.The acylation reaction system with other organic solvent as solvent was first studied using acid chloride and anhydride as acylating agents,respectively.The effect of different solvents,catalysts,reactant ratios,mixing temperature,reaction temperature,and reaction time on the selectivity and yield of the target product 2-methyl-6-acylnaphthalene were studied.With acyl chloride as acylating agent,AlCl₃ as catalyst and nitrobenzene as solvent,under the optimal reaction conditions,the selectivity and yield of 2-methyl-6-propanoyl naphthalene?2,6-MPN?were 87.5%and 85.8%,and the selectivity and yield of 2-methyl-6-acetyl naphthalene?2,6-MAN?were 75.5%and 74.4%,respectively.When anhydride was used as acylating agent,AlCl₃ was the catalyst and nitrobenzene was the solvent,under the optimal reaction conditions,the selectivity and yield of 2,6-MPN were 88.6%and 84.1%,and the selectivity and yield of 2,6-MAN were 76.3%and 73.8%,respectively.Furthermore,acyl chloride and anhydride were also used as acylating agents and solvents.The effect of differernt catalysts,reactant ratios,reaction temperature,reaction time on the selectivity and yield of2-methyl-6-acylnaphthalene were also investigated.When acyl chloride was used as acylating agent and solvent,and AlCl₃ as the catalyst,under the optimal reaction conditions,the selectivity and yield of 2,6-MPN were 73.0%and 71.9%,and the selectivity and yield of 2,6-MPN 55.4%and 54.1%,respectively.When the anhydride was used as the acylating agent and the solvent,and FeCl₃ as the catalyst,under the optimal reaction conditions,the selectivity and yield of 2,6-MPN were 62.3%and40.9%,and the selectivity and yield of 2,6-MAN were 62.3%and 40.9%,respectively.Finally,the kinetics of the acylation reaction of 2-MN in a microchannel reactor was studied.The order of the reactants were determined by the isolated-initial concentration method,and then the kinetic equation of the reaction were presented by the Arrhenius formula.