Process for preparing resorcinol

Claim 2

A process for preparing resorcinol from an oxidation product of diisopropylbenzene which comprises (1) a first step of pre-treating an oxidation product of m-diisopropylbenzene composed of m-diisopropylbenzene dihydroperoxide and by-product m-substituted carbinol hydroperoxide and/or dicarbinol with hydrogen peroxide in the presence of sulfuric acid as an acid catalyst in a heterogeneous system of an aqueous aromatic hydrocarbon solvent at a temperature of about 30° C. to 60° C., for a reaction time of from about 3 minutes to about 60 minutes, the pre-treatment being performed while removing by-product water as an azeotrope with the aromatic hydrocarbon in the treating system, while maintaining the concentrations of the hydrogen peroxide and the acid catalyst in the aqueous solution of the treating system at 1 to 15 moles/liter, and 0.5 to 5 moles/liter, respectively, separating the aromatic hydrocarbon solvent layer containing the pre-treated reaction product from the aqueous layer containing the hydrogen peroxide of the first step pre-treatment; and (2) a second step of acid-cleaving the pre-treated reaction product recovered in the aromatic hydrocarbon solvent layer, in the substantial absence of hydrogen peroxide at a temperature of about 40° to 100° C., the second step being performed in the presence of an acid-cleavage catalyst selected from the group consisting of sulfuric acid and silica-alumina, the amount of sulfuric acid being 0.1 to 15% by weight, based on the pre-treated reaction product and the amount of silica-alumina being 2 to 100% by weight based on the pre-treated reaction product and recovering the resorcinol.

Claim 3

The process of claim 1 wherein the concentration of the sulfuric acid catalyst in the first step is 0.9 to 2.9 moles/liter.

Claim 4

The process of claim 1 wherein the total amount of hydrogen peroxide used in the pre-treatment is 2 to 20 equivalents based on the total amount of the carbinol groups in the by-products.

Claim 5

The process of claim 1 wherein the aromatic hydrocarbon solvent is selected from the group consisting of benzene, toluene, cumene and xylene.

Claim 6

The process according to claim 1 wherein the total amount of hydrogen peroxide used in the pre-treatment is 3 to 15 equivalents based on the total amount of the carbinol groups in the by-products and wherein the reaction time of the pre-treatment is from about 5 to 15 minutes.

Claim 7

The process according to claim 1 wherein the aqueous layer of the heterogeneous system containing unreacted hydrogen peroxide and acid catalyst is recycled to the step (1) pre-treatment.

Claim 8

The process according to claim 1 wherein the reaction temperature, concentration of acid catalyst and reaction time of the step (1) pre-treatment are such that the acid cleavage rate (A 1 /A 0 ), in which A 0 is the number of equivalents of the --OOH groups in the oxidation product feed and A 1 is the number of equivalents of the --OOH groups in the reaction product, does not exceed about 2 percent.

Claim 9

A process for preparing resorcinol from m-diisopropyl benzene dihydroperoxide which comprises (1) pre-treating at least one by-product obtained from the oxidation of m-diisopropylbenzene to m-diisopropylbenzene dihydroperoxide, said by-product selected from the group consisting of m-substituted carbinol hydroperoxide and dicarbinol, with hydrogen peroxide in the presence of an acid catalyst selected from the group consisting of sulfuric acid, perchloric acid, hydrochloric acid, phosphoric acid, chloroacetic acid and paratoluene sulfonic acid in a heterogeneous system of an aqueous aromatic hydrocarbon solvent at a temperature of about 30° C. to 60° C., for a reaction time of about 3 minutes to about 60 minutes, while removing by-product water as an azeotrope with the aromatic hydrocarbon in the treating system, while maintaining the concentrations of the hydrogen peroxide and acid catalyst in the aqueous solution of the heating system, at 1 to 15 moles/liter, and 0.5 to 5 moles/liter, respectively, separating the aromatic hydrocarbon solvent layer containing the pre-treated reaction product from the aqueous layer containing the hydrogen peroxide of the first step pre-treatment; and (2) a second step of acid-cleaving the pre-treated reaction product recovered in the aromatic hydrocarbon solvent layer, in the substantial absence of hydrogen peroxide, at a temperature of about 40° C. to 100° C., the second step being performed in the presence of acid-cleaving catalyst selected from the group consisting of sulfuric acid and silica-alumina, the amount of sulfuric acid being 0.1 to 15% by weight, based on the the pre-treated reaction product and the amount of silica-alumina being 2 to 100% by weight, based on the pre-treated reaction product and recovering the resorcinol.

Claim 10

A process for preparing resorcinol from m-diisopropyl benzene dihydroperoxide which comprises (1) pre-treating at least one by-product obtained from the oxidation of m-diisopropylbenzene to m-diisopropylbenzene dihydroperoxide, said by-product selected from the group consisting of m-substituted carbinol hydroperoxide and dicarbinol, with hydrogen peroxide in the presence of an acid catalyst selected from the group consisting of sulfuric acid, perchloric acid, hydrochloric acid, phosphoric acid, chloroacetic acid and paratoluene sulfonic acid in a heterogeneous system of an aqueous aromatic hydrocarbon solvent at a temperature of about 30° C. to 60° C., for a reaction time of about 3 minutes to about 60 minutes, while removing by-product water as an azeotrope with the aromatic hydrocarbon in the treating system, while maintaining the concentrations of the hydrogen peroxide and acid catalyst in the aqueous solution of the heating system, at 1 to 15 moles/liter, and 0.5 to 5 moles/liter, respectively, separating the aromatic hydrocarbon solvent layer containing the pre-treated reaction product from the aqueous layer containing the hydrogen peroxide of the first step pre-treatment; and (2) a second step of acid-cleaving the pre-treated reaction product recovered in the aromatic hydrocarbon solvent layer, in the substantial absence of hydrogen peroxide, at a temperature of about 40° C. to 100° C., the second step being performed in the presence of acid-cleaving catalyst selected from the group consisting of sulfuric acid and silica-alumina, the amount of sulfuric acid being 0.1 to 15% by weight, based on the the pre-treated reaction product and the amount of silica-alumina being 2 to 100% by weight, based on the pre-treated reaction product and recovering the resorcinol.

Claim 11

The process of claim 8 wherein the step (1) pre-treatment is carried out on the by-product m-substituted carbinol hydroperoxide or dicarbinol or both in the presence of the m-diisopropylbenzene dihydroperoxide oxidation product of m-diisopropylbenzene.

Claim 12

The process of claim 8 wherein the step (1) pre-treatment is carried out on the by-product, m-substituted carbinol hydroperoxide or dicarbinol or both which has been separated from the m-diisopropylbenzene dihydroperoxide obtained from the oxidation of m-diisopropylbenzene and wherein the step (2) acid-cleaving is performed after recombining the m-diisopropylbenzene dihydroperoxide oxidation product with the pre-treated by-product.

Claim 13

The process of claim 8 wherein sulfuric acid is used as the acid catalyst in the step (1) pre-treatment.

Claim 14

The process of claim 8 wherein the total amount of hydrogen peroxide used in the pre-treatment is 2 to 20 equivalents based on the total amount of the carbinol groups in the by-products.

Claim 15

The process according to claim 8 wherein the total amount of hydrogen peroxide used in the pre-treatment is 3 to 15 equivalents based on the total amount of the carbinol groups in the by-products and wherein the reaction time of the pre-treatment is from about 5 to about 15 minutes.

Claim 16

The process according to claim 8 wherein the aqueous layer of the heterogeneous system containing unreacted hydrogen peroxide and acid catalyst is recycled to the step (1) pre-treatment.

Claim 17

The process according to claim 8 wherein the reaction temperature, concentration of acid catalyst and reaction time of the step (1) pre-treatment are such that the acid cleavage rate (A 1 /A 0 ), in which A 0 is the number of equivalents of the --OOH groups in the oxidation product feed and A 1 is the number of equivalents of the --OOH groups in the reaction product, does not exceed about 2 percent.