Optimum Operation in the Alkali Fusion of Sodium Alkylbenzene Sulfonates.

Abstract

When the conventional alkali fusion techniques are applied to the alkylated benzenesulf onic acids, the corresponding phenols are obtained in relatively low yields(p-methyl 69%, p-ethyl 58%, p-isopropyl 54%). In the present study, conditions for the alkali fusion of aromatic sulfonic acid salts containing methyl-, ethyl-, and isopropyl-groups in the para or ortho position have been studied in detail. The optimum conditions for the sodium hydroxide fusion of unsubstituted sodium benzenesulfonate were first established. These conditions were successfully applied to the fusion of alkyl substituted sulf onates effecting improved yields. Thus, pethyl-and p-isopropyl-phenols were obtained in yields of 92 and 88%, respectively, with potassium hydroxide. When sodium hydroxide was used, p-methyl-, omethyl-, p-ethyl-, and p-isopropyl-phenols were obtained in yields of 95, 93, 82, and 71%, respectively. This indicates that the reactivities are affected by the type of substituent. Though p-substituted sulfonates are hardly soluble in fused sodium hydroxide, sodium p-toluenesulf onate becomes soluble at about 365... Thus, the treatment at high temperatures for a short time is recommended for the improvement of the yield.