合成对烷基苯甲酸的新工艺研究

A NEW SYNTHETIC PROCESS OF P-ALKYLBENZOIC ACID

以工业废氯气的回收碱液次氯酸钠为氧化剂 ,在相转移催化剂 PEG作用下氧化甲基酮合成了对烷基苯甲酸 R ?COOH [R=CH3、CH3( CH2 ) n,n=1～ 4 ]。反应中加入少量相转移催化剂可使甲基酮有机相和次卤酸盐无机相很好相溶 ,改变了以往需大量有机溶剂才能使氧化反应进行的方法。同时 ,还对氧化反应的物料比、反应混合液 p H值及相转移催化剂的选取和用量做了深入的研究。在次氯酸钠与甲基酮的摩尔比为 4∶ 1 ,反应混合液 p H≥ 1 3,相转移催化剂为 PEG 4 0 0 ,用量为每摩尔甲基酮需 PEG2 0 0 m L为最佳工艺条件(要求次卤酸钠有效氯为 1 2 % )下 ,合成对烷基苯甲酸收率大于 85% ,纯度大于 95% 。

Alkybenzoic acid R COOH ,(R=CH 3,CH 3(CH 2) n,n=1～4) was synthesized by sodium hyprochlorite solution, which was obtained by waste chlorine gas of industry dissolved in alkail liquor according to the halform reaction. Adding one kind of phase transfer catalyst (PEG) in the mixture of reaction could make it take place very well without any organic solvent. The technological conditions such as raw material ratio, the pH value range, and the quantity of catalyst were discussed. A higher yield (>85%) and purity(GC>95%) were obtained in the conditions of alkylacetophenone∶sodium hyprochlorite=1∶4, the pH ≥13, and 200 mL PEG400 per molecule alkylacetophenone. A new method for industrial production was given.