| 摘要 |
PURPOSE:To obtain the titled compound economically, by using fine particle of crystalline aluminosilicate having specific silica/alumina ratio as a catalyst in the vapor-phase methylation of xylene and/or 1,2,4-trimethylbenzene with methanol. CONSTITUTION:Xylene and/or 1,2,4-trimethylbenzene is methylated with methanol in vapor phase to obtain 1,2,4,5-tetramethylbenzene useful as an intermediate of pyromellitic acid (a raw material of polyimide resin). In the above process, crystalline alumino-silicate fine powder having a silica/alumina ratio of >=20, preferably >=30 and an average particle diameter of <=1mum, preferably <=0.5mum, e.g. ZSM-5, ZSM-11, ZSM-12, etc., especially ZSM-5, is used as the catalyst. The objective compound can be produced in high selectivity suppressing the deactivation of the catalyst. |
