A diester of .alpha.-acetyl-.alpha.'-methyl succinic acid is prepared in improved yield under substantially anhydrous process conditions which minimizes decomposition of that diester by reacting an acetoacetate ester with an .alpha.-halopropionate ester in a solvent containing a nonpolar, aprotic liquid at from about 50.degree. C. to reflux temperature in the presence of a phase transfer agent, a catalytic amount of iodide ion and solid form, substantially anhydrous alkali metal base or basic salt having a high surface area (a size of about 60 mesh or smaller). The resulting diesters can also be used under the stabilizing reaction mixture conditions of this invention as intermediates in processes for making ibuprofen by combining and reacting the .alpha.-acetyl-.alpha.'-methylsuccinate diester with vinyl isobutyl ketone, (or the corresponding Mannich base plus an alkylating agent) and an alkali metal base for a time sufficient to form a reaction mixture containing the .alpha.-methyl-.alpha.'-acetyl-.alpha.'-(5-methyl-3-oxohexyl)succinate ester, which can then be converted to ibuprofen by procedures now known.
在基本无
水的反应条件下,通过将
乙酰丙酮酯与α-卤代
丙酸酯在含有非极性、无质子液体溶剂的条件下反应,添加相转移剂、催化剂
碘离子和固态、基本无
水的碱
金属基或高表面积的碱
金属盐(粒径约为60目或更小),可以提高α-乙酰基-α'-
甲基琥珀酸双酯的收率。根据本发明的稳定反应混合物条件,产生的双酯也可用作制备
布洛芬的中间体,方法是将α-乙酰基-α'-
甲基琥珀酸双酯与
乙烯基异
丁酮(或相应的曼尼希碱加上烷基化剂)和碱
金属基反应一段时间,形成含α-甲基-α'-乙酰基-α'-(5-甲基-3-氧代己基)
琥珀酸酯的反应物混合物,然后可按已知方法将其转化为
布洛芬。