Trimethyl Phenol 2,3,6-TMP

6- Trimethyl phenol, a key intermediate for vitamin E synthesis, is made from m-cresol and is easily the largest derivative of m-cresol. 

6- Trimethyl phenol has heen produced selectively hy gas phase methylation of m-cresol with methanol at 300-4 00° C rmder normal pressme on ortho-selective metal oxide catalysts as used for selective methylation of phenol. The reaction occurs in mriltituhe reactors with a fixed catalyst. Iron oxide catalysts modified with oxides of other metals (Zn, Cr, and Sn) or Mg and Si are particularly suitahle. At a temperature of approx. 350°C and an LHSV of Ihr an initial mixture of m-cresol, methanol and steam in a molar ratio of 1.6 1 gives 

6-trimethyl phenol in yields of 90-95% relative to m-cresol at virtually complete m-cresol conversion. Small quantities of 2,5-xylenol and 2,4,6-trimethyl phenol are the main hy products. 2,3,6-Trimethyl phenol is purified by distillation from the mixture. The commercial product is 99% pure [1]. 

6- Trimethyl phenol demand is expected to grow worldwide by at least 5% per annum during the next decade. Some industry experts, however, fear that now there is over capacity situation for TMP, which may last for some years. Main producers and their nameplate capacities are  

Vitamin E being the fastest growing vitamin, 2,3,6-TMP constitutes the fastest growing m-cresol derivative. One critical factor for fast growth will, however, depend on availability of m-cresol. Currently, m-cresol is available mostly in Japan, USA, and W. Europe mostly as a co-product during manufacture of BHT from meta-para-cresols. Can also be obtained by methylation of 2,6-xylenol on y-aluminium oxide at about 355°C using a 2,6 xylenohmethanol ratio of 2 1. 

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