Sulphophenyl esters can be made amongst other routes by reacting an acyl halide with a phenol sulphonate salt, but it has been suggested in the prior art that there are substantial problems or disadvantages associated with carrying out the reaction in the presence of an organic solvent such as gelation of the reaction medium or excessive reaction times.
In the present invention, the process employs as organic solvent high boiling point primarily aliphatic hydrocarbons which forms with linear acyl halide a reaction medium in which products of high and/or improved purity and/or yield are obtainable without gelation and in reasonable reaction periods, especially between C₆-C₁₀ linear acyl chlorides and sodium phenol sulphonate.
It has been found advantageous to pre-dry the phenol sulphonate salt by heating it when dispersed in a high boiling aliphatic or aromatic hydrocarbon solvent such that water and solvent are co-removed, with the result that in a subsequent esterification reaction with acyl halide an improvement in yield and/or purity of the sulphophenyl ester can be achieved.
除其他途径外,还可通过酰基卤与
苯酚磺酸盐反应制得
硫代苯酯,但现有技术表明,在有机溶剂存在的情况下进行反应存在大量问题或缺点,如反应介质凝胶化或反应时间过长。
在本发明中,该工艺采用高沸点的主要是脂肪族烃类作为有机溶剂,它与线性酰基卤化物形成一种反应介质,在这种介质中,特别是 C₆-C₁₀ 线性酰基
氯化物和
苯酚磺酸钠之间的反应介质,可以获得高纯度和/或改进纯度和/或产率的产品,而不会发生凝胶化,反应时间也合理。
在
苯酚磺酸钠分散在高沸点脂肪族或芳香族烃类溶剂中时,通过加热使其预干燥,从而使
水和溶剂共同脱除,这样做是有利的,其结果是在随后与酰基卤化物的酯化反应中,可以提高
硫代苯酯的产率和/或纯度。