Dimethyl 2,2-dimethylmalonate is a versatile organic compound. It is commonly used as a raw material in the synthesis of pharmaceutical intermediates such as pipemidic acid, fragrance intermediates, and pesticide intermediates.
Synthesis of dimethyl 2,2-dimethylmalonate: a synthesis method of dimethyl 2,2-dimethylmalonate: weigh 104.2g of 2,2-dimethyl-1,3-propanediol, catalyst phosphotungstic acid 0.2g, under constant stirring was added in batches to 340g of 50% hydrogen peroxide solution, which oxidized to the crude 2,2-dimethylmalonate solution, and the molar ratio of 2,2-dimethyl-1,3-propanediol and hydrogen peroxide was 1:5. concentrated and acidified, and then recrystallized with deionized water to obtain 2,2-dimethylmalonate crystal. ,3-propanediol to hydrogen peroxide at a molar ratio of 1:5. Concentrate and acidify, cool to obtain 2,2-dimethylmalonic acid crystals, pump-filter, and then recrystallize with deionized water to obtain 2,2-dimethylmalonic acid pure product in 86% yield. Then 2,2-dimethylmalonic acid was esterified with methanol using sodium hydrosulfate monohydrate as a catalyst with an addition amount of 10% of the mass of 2,2-dimethylmalonic acid, and cyclohexane as a water-carrying agent. The molar ratio of methanol to 2,2-dimethylmalonic acid was 6:1, the reaction temperature was 70-75C, and the reaction time was 2-4 h. At the end of the reaction, the cyclohexane and methanol were evaporated, and the liquid was separated and set aside for use, and the crude product 2,2-dimethylmalonic acid dimethyl ester was washed with water, and after the liquid was separated, it was dried with anhydrous magnesium sulfate, and distilled under reduced pressure with an oil pump, and the 106-110C fractions were collected to obtain the product 2,2-dimethylmalonic acid dimethyl ester. Dimethyl 2,2-dimethylmalonate, yield 96%. Purity 99.96%.
