Sulfonation of chloro- and dichloroanisoles with concentrated aqueous sulfuric acid and sulfur trioxide. Demethylation of chloroanisolesulfonic acids in sulfuric acid systems
作者:Peter de Wit、Hans Cerfontain
DOI:10.1002/recl.19881070605
日期:——
The nine chloro- and dichloroanisoles have been sulfonated with sulfuric acid. The observed sulfonic acid isomer distributions are determined mainly by the ortho- and para- directing effect of the methoxy substituent. In the reaction with sulfuric acid, the initially formed chloro- and dichloroanisolesulfonic acids are demethylated to give the corresponding phenolsulfonic acids. Demethylation occurs
九种氯苯甲醚和二氯苯甲醚已用硫酸磺化。观察到的磺酸异构体分布主要取决于甲氧基取代基的邻位和对位作用。在与硫酸的反应中,将最初形成的氯代和二氯茴香醚磺酸脱甲基,得到相应的苯酚磺酸。脱甲基化仅在甲氧基取代基在空间上受邻氯和/或邻位阻碍的情况下发生-磺基取代基。2,3-和3,5-二氯茴香醚与发烟硫酸的反应最初分别产生4,6-和2,4-二磺酸。通过直接的磺基甲基化或通过原脱甲基化,随后进行硫酸化,将二磺酸转化为相应的硫酸氢盐。2,3-二氯-4,6-二磺基苯基硫酸氢环化成1,3,2,4-苯并二恶二硫辛2,2,4,4-四氧化物4。