申请人:——
公开号:US20040242891A1
公开(公告)日:2004-12-02
An improved method of producing keto acids having the formula (I), wherein R1 and R2 independently represent (a) hydrogen,
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wherein at least one of R1 and R2 do not stand for hydrogen, (b) branched or unbranched alkyl of 1-18 carbon atoms, which may be substituted by C1-C4alkoxy or 2- or 3-tetrahydrofuryl, (c) a cycloalkyl of 4-8 carbon atoms, (d) C4-C8cycloalkyl-C1-C4alkyl, or phenyl, wherein both, cycloalkyl and phenyl, may be substituted by at least one member selected from the group consisting of halogen atoms and alkyls having 1-4 carbon atoms, (e) an aralkyl of 7-10 carbon atoms, or (f) R1 and R2 together with the adjacent nitrogen atom may form a heterocyclic ring, by reacting a m-amino phenol having the formula (II) with phthalic anhydride at an elevated temperature in the absence of an organic solvent, which comprises: (I) mixing m-amino phenol II and phthalic anhydride in a molar ratio of from 0.5 to 10:1, (II) melting the mixture of step I at an elevated temperature, (III) choosing a reaction time in the range of from 5 minutes to 40 hours, (IV) then separating the liquid phase from the solid phase as well as a method in which a solvent is added after the reaction.
一种生产具有式(I)的酮酸的改进方法,其中 R1 和 R2 独立地代表 (a) 氢、
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其中 R1 和 R2 中至少有一个不代表氢,(b) 1-18 个碳原子的支链或未支链烷基,可被 C1-C4 烷氧基或 2- 或 3-四氢糠基取代,(c) 4-8 个碳原子的环烷基,(d) C4-C8 环烷基-C1-C4 烷基或苯基,其中环烷基和苯基均可被选自卤素原子组成的组中的至少一个成员取代、(e) 7-10 个碳原子的芳烷基,或 (f) R1 和 R2 连同邻近的氮原子可形成杂环:(I) 将间氨基苯酚 II 和邻苯二甲酸酐以 0.5至10:1的摩尔比混合,(II)在高温下熔化步骤I的混合物,(III)选择5分钟至40小时的反应时间,(IV)然后分离液相和固相以及在反应后加入溶剂的方法。