Synthesis of 2,2-Dimethyl-propanedioic Acid Dimethyl Ester

2,2-Dimethyl-propandioic acid dimethyl ester was synthesized using dimethyl malonate and iodomethane as raw materials and sodium methoxide as catalyst.Factors influencing the reaction were studied.The experimental conditions were optimized.The yield was 81.3%,and the purity was over 99.9%.The optimum conditions are as follows: n(dimethyl malonate)∶n(iodomethane)=1.0∶2.6;n(iodomethane)∶n(sodium methoxide)=1.0∶1.0;refluxed for 6 h,80 mL methanol solvent.The product was idenlified by elemental analysis,IR and GC.The process was already industrialized.