Synthesis
(1), from chlorotripentane and formaldehyde under acidic conditions for condensation reaction, catalyzed by Zn/Co/Sb composite catalyst, the reaction temperature of 60 C, reaction time of 5h, the preparation of pinacolone, Zn/Co/Sb composite catalyst in the amount of each component of the material sum and the amount of chlorotripentane between the ratio of the substance of the ratio of 3:50;
(2), using pinacolone, sodium hydride and dimethyl carbonate as raw materials, toluene as solvent, at 55 ~ 60 C, stirring reaction and then cooled, at pH = 4, the preparation of 4, 4-dimethyl-3-oxo-pentanoic acid methyl ester crude, pinacolone content of water 0.2fft.%,the moisture content of the toluene & lt; 0.2Wt.%;/p>
(3)4, 4_Dimethyl-3-oxo-pentanoic acid methyl ester crude. ,4_Dimethyl-3oxo-pentanoic acid methyl ester crude product was distilled under a vacuum of less than 1 mm Hg and a temperature of 90C. The 4,4-dimethyl-3oxo-pentanoic acid methyl ester obtained was of high purity and high yield, with the main content of 98 % or more, and the total yield also reached 96 %.
