Beta - Methyl Glutaric Acid Synthesis And Research Of Selective Single Binary Carboxylic Acid Esterification

β-methylglutaric acid,3-methylglutaric acid, methylglutaric acid, is an importantcuratorial and fine chemical intermediate. Methyl β-methylglutarate have a very widerange of applications in pharmaceutical industry. Therefore, in this paper the method ofsynthesis of β-methylglutaric acid, methyl β-methylglutarate were optimized, then themethod of methyl β-methylglutarate was also applied in other dicarboxylic acids. At lastachieved a good result.Firstly, Optimization of synthesis of β-Methylglutaric acid: β-Methylglutaric acidwas synthesized through three steps of ammonolysis, addition-condensation,hydroxylation-decarboxylation by using ethyl cyanoacetate as a raw material, theoverall yield was77%. Conditions of every step was optimized. The process is easy togain materials, simple operation, high yield, solvent reusing, low environmentalpollution and suitable to scale production. The product and by-product ofhydroxylation-decarboxylation were analysed using indirect method by GC-MS and thepossible mechanism was discussed.Second, optimization of monoesterification of dicarboxylic acids: the process isgreen environmental protection, stronger applicability and selectivity. The best craft ofselectivity mono-esterification is Vsolvent:mdicarboxylic acids=2:1, ndicarboxylic acid:mstorng-acid cationexchange resin=1:10, selectivity was above90%.The structures of inter-mediate and production are confirmed by IR, GC-MS,1H-NMR.