Studies On The Synthesis Of 1,3-Acetone Dicarboxylic Acid And Its Derivatives

1,3-Acetone dicarboxylic acid and its derivatives are importantorganic synthesis and pharmaceutical intermediates, can be used forsynthesis of the endo-nortropine, granisentron, benztropine, strontiumranelate and other medications. Therefore, the study of synthesis of1,3-acetone dicarboxylic acid and its derivatives is significant.In this paper, we used the citric acid as the raw material, andobtained the 1,3-acetone dicarboxylic acid by decarboxylation withconcentrated sulfuric acid; used the citric acid and concentrated sulfuricas raw materials, after reaction, obtained the diethyl 1,3-acetonedicarboxylic acid by direct esterification with ethanol; obtained thedimethyl 1,3-acetone dicarboxylic acid by direct esterfication withmethanol; obtained the diisopropyl 1,3-acetone dicarboxylic acid bydirect esterfication with isopropanol. Through the optimization ofreaction conditions,we found the optimum conditions for synthesis of 1,3-acetone dicarboxylic acid was: the mole ratio of concentrated sulfuricacid and citric acid was 9:1, reaction temperature was 30℃, reaction timewas 18 hours,the yield was 87.9%.In addition, We used the diethyl 1,3-acetone dicarboxylate thatsynthesized by ourself react with the p-methoxy aniline at 160℃, andafter ketonic decomposition by 10% mass concentration sodiumhydroxide, obtained the N-(4-methoxybenzene)-3-oxo-butyramide. Weused it to synthesis the 4-methyl-6-methxoyl-2(1H)-quinolinone bycyclization with concentrated sulfuric acid, the total yield was 66.5%. Weused the diethyl 1,3-acetone dicarboxylate react with the aniline at 160℃,after ketonic decomposition by 10% mass concentration sodiumhydroxide, obtained N-benzene-3-oxo-butyramide. We used it tosynthesis the 4-bromomethyl-2(1H)-quinolinone by bromized andcyclization,the total yield was 50.3%,4-bromomethyl-2(1H)-quinolinoneis the important intermediate of the rebamipide.