メタノールによる芳香族化合物の核メチル化

抄録

The methylation of aromatic compounds with methanol in vapour or liquid phase was studied on various catalysts. In these reactions, a flow method was adopted and the liquid phase methylation of phenol was carried out in an autoclave. The reaction products were analyzed with gas liquid chromatography.
As aromatic materials, o-chlorotoluene, o-, m-, p-xylene, phenol, o-cresol, aniline and o-toluidine were examined. The catalysts effective in methylation were characteristic of the substituents, i. e., SiO₂-Al₂O₃-BF₃ to o-chlorotoluene, SiO₂-Al₂O₃ modified with ethylenediamine and Al₂O₃-HF to the selective methylation of o-, m- and p-xylene, condensed phosphoric acid (CPA)-kieselguhr (KG), CPA-BF₃-KG and Al₂O₃-MgO-SiO₂ to the m-position of phenol, Ce₂O₃-MnO-MgO to the o-position of phenol, and Al₂O₃-MgO to o-toluidine and aniline, respectively. Finally, the relation between catalytic activity and selectivity of the methylated position was also discussed from the standpoint of the acid properties of the catalysts.