Preparation of 5-sec-alkyl-m-cresol

A method for preparing 5 sec-alkyl-m-cresols in high concentrations comprising:

• a. alkylating m-cresol with an alkene at a temperature of at least about 100.degree. C. over a catalyst selected from finely divided silica-alumina clays and finely divided molecular sieves of the faujasite type to form a mixture of alkylated m-cresol products wherein the molar ratio of the alkene to m-cresol is from about 0.5:1.0 to about 1.0:1.0;
• and
• b. isomerizing the alkylated mixture over the same catalyst for at least about two hours at a temperature of from about 250.degree. C. to 400.degree. C. wherein the catalyst is from about 1.0% to about 10.0% by weight based on m-cresol;
• c. fractionally distilling the isomerized alkylated mixture to obtain the 5 sec-alkyl-m-cresol.

A method for preparing 5 sec-alkyl-m-cresols in high concentrations comprising:

• a. alkylating m-cresol with an alkene at a temperature of at least about 100.degree. C. over a catalyst selected from finely divided silica-alumina clays and finely divided molecular sieves of the faujasite type to form a mixture of alkylated m-cresol products wherein the molar ratio of alkene to m-cresol is from about 0.5:1.0 to about 1.0:1.0;
• and
• b. isomerizing the alkylated mixture over the same catalyst for at least about two hours at a temperature of from about 250.degree. C. to 400.degree. C. wherein the catalyst is from about 1.0% to about 10.0% by weight based on m-cresol;
• c. fractionally distilling the isomerized alkylated mixture to obtain the 5 sec-alkyl-m-cresol;
• d. recycling the undesired alkylated products.

A method for preparing 5 sec-alkyl-m-cresol in high concentrations comprising:

• a. alkylating m-cresol with an alkene at a temperature of at least about 100.degree. C. over a catalyst selected from silica-alumina clays and molecular sieves of the faujasite type to form a mixture of alkylated m-cresol products wherein the molar ratio of alkene to m-cresol is from about 0.5:1.0 to about 1.0:1.0;
• and
• b. isomerizing the alkylated mixture over the same catalyst for at least about two hours at a temperature of from about 250.degree. C. to 400.degree. C. wherein the catalyst is from about 1.0 to about 10.0% by weight based on the m-cresols, alkylated and unalkylated;
• c. fractionally distilling the isomerized alkylated mixture to obtain the 5 sec-alkyl-m-cresol;
• d. recycling the unreacted m-cresol to the alkylation step and the 6-isomer, 4-isomer, 2-isomer, di-alkylated m-cresols and other undesired alkylated products to the isomerization step.

A method for preparing m-thymol in high concentrations comprising:

• a. isopropylating m-cresol with propylene at a temperature of at least about 100.degree. C. over a catalyst selected from finely divided silica-alumina clays and finely divided molecular sieves of the faujasite type to form a mixture of isopropylated m-cresol products wherein the molar ratio of propylene to m-cresol is from about 0.5:1.0 to about 1.0:1.0;
• and
• b. isomerizing the isopropylated mixture over the same catalyst for at least about two hours at a temperature of from about 250.degree. c. to 400.degree. C. wherein the catalyst is from about 1.0% to about 10.0% by weight based on m-cresol;
• c. fractionally distilling the isomerized isopropylated mixture to obtain the m-thymol.

A method for preparing m-thymol in high concentrations comprising:

• a. isopropylating m-cresol with propylene at a temperature of at least about 100.degree. C. over a catalyst selected from finely divided silica-alumina clays and finely divided molecular sieves of the faujasite type to form a mixture of isopropylated m-cresol products wherein the molar ratio of propylene to m-cresol is from about 0.5:1.0 to about 1.0:1.0;
• and
• b. isomerizing the isopropylated mixture over the same catalyst for at least about 2 hours at a temperature of from about 250.degree. C to 400.degree. C. wherein the catalyst is from about 1.0% to about 10.0% by weight based on m-cresol;
• c. fractionally distilling the isomerized isopropylated mixture to obtain the m-thymol;
• d. recycling the undesired isopropylated products.

A method for preparing m-thymol in high concentrations comprising:

• a. isopropylating m-cresol with propylene at a temperature of at least about 200.degree. C. over a catalyst selected from finely divided silica-alumina clays and finely divided molecular sieves of the faujasite type to form a mixture of isopropylated m-cresol products wherein the molar ratio of propylene to m-cresol is from about 0.5:1.0 to about 1.0:1.0;
• and
• b. isomerizing the isopropylated mixture over the same catalyst for at least about 2 hours at a temperature of from about 250.degree. C. to 400.degree. C. wherein the catalyst is from 1.0 to about 10.0% by weight based on the m-cresols, isopropylated and unisopropylated;
• c. fractionally distilling the isomerized isopropylated mixture to obtain the m-thymol;
• d. recycling the unreacted m-cresol and thymol, p-thymol, victhymol, di-isopropylated m-cresols and other undesired isopropylated products to the isopropylating step.

A method for simultaneously preparing thymol and m-thymol comprising:

• a. isopropylating m-cresol with propylene at a temperature of at least about 100.degree. C. over a catalyst selected from finely divided silica-alumina clays and finely divided molecular sieves of the faujasite type to form a mixture of isopropylated m-cresol products wherein the molar ratio of propylene to m-cresol is from about 0.5:1.0 to about 1.0:1.0;
• and
• b. recovering the thymol by fraction distillation;
• c. combining the undesirable fractions and residue from the thymol fractional distillation and isomerizing this mixture for at least about 2 hours at a temperature of from about 250.degree. C to 400.degree. C. wherein the catalyst is from about 1.0 to about 10.0% by weight based on the m-cresols, isopropylated and unisopropylated;
• d. fractionally distilling the isomerized isopropylation mixture to obtain m-thymol.