PREPARATION OF 5-SEC-ALKYL-M-CRESOL

摘要

This disclosure is directed to a method for preparing 5-sec-alkyl-m-cresol in high concentrations and yields comprising alkylating m-cresol with an alkene over a solid catalyst selected from finely divided silica alumina clays and finely divided molecular sieves and then isomerizing the alkylated m-cresol product over the same catalyst for at least two hours at temperatures of at least about 250 DEG C. The ratio of alkene to m-cresol is from about 0.5:1.0 to about 1.0:1.0. The resulting isomerized alkylated m-cresol contains a ratio of 5-alkyl-m-cresol to 6-alkyl-m-cresol of at least 2.5:1 and a ratio of 5-alkyl-m-cresol to 4-alkyl-m-cresol of at least 3.0:1.0. The desired 5-alkyl-m-cresol may be obtained from the isomerized alkylated-m-cresol reaction product by fractional distillation. The undesired alkylated-m-cresol isomers and unreacted m-cresol may be recycled into the alkylation and/or isomerization step. The method is particularly useful for preparing 5-isopropyl-m-cresol(m-thymol).