| 摘要 |
PURPOSE:To obtain hexamethylbenzene useful as a methylating agent in both high selectivity and yield polymethylbenzene with methanol in the presence of a silica-alumina catalyst. CONSTITUTION:The objective hexamethylbenzene can be obtained by reaction of a polymethylbenzene with methanol at 300-600 (pref. at 350-550) deg.C using, as catalyst, a silica-alumina inexpensive and readily available, also excellent in heat resistance and easy to regenerate, pref. 0.5-20 in the ratio silica/alumina and >=100m<2>/g in specific surface area. The polymethylbenzene is e.g. xylene, trimethylbenzene, tetramethylbenzene, pentamethylbenzene, a mixture thereof (esp. pref. tetramethylbenzene, pentamethylbenzene or a mixture thereof). The hexamethylbenzene thus obtained is useful e.g. as a methylating agent for synthesizing e.g. 4,4-dimethylbiphenyl, etc., from biphenyl. |
