Method for preparing o-toluic acid and phthalide from phthalic anhydride

A technology of o-toluic acid and phthalic anhydride, which is applied in the field of chemical product preparation to achieve the effects of mild reaction conditions, broad requirements, and cost savings

Pending Publication Date: 2020-01-24
TANGSHAN XUYANG CHEM IND CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there is currently no method for the controlled preparation of o-toluic acid and phthalide using phthalic anhydride as a raw material

Method used

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  • Method for preparing o-toluic acid and phthalide from phthalic anhydride

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0055] (1) Preparation of hydrogenation catalyst

[0056] Prepare a solution of 8.3g of nickel nitrate and 12.5g of pure water, weigh 10g of 60-80 mesh alumina particles, impregnate the two in equal volume for 12 hours, dry them continuously at 80°C, and then place them in a muffle furnace Roast at 450°C for 3 hours, then slowly drop to room temperature; prepare a solution with 0.13g of cerium nitrate and 0.13g of ruthenium nitrate and 12.5g of pure water, and soak the same volume with the above-mentioned roasted product in a 40°C thermostat for 12 hours again. After the secondary impregnation is completed, dry it at 80°C, put it into a muffle furnace and bake it at 450°C for 2 hours, and take it out after cooling down to room temperature for later use.

[0057] The catalyst needs to be activated by hydrogen before it can be used again. The activation uses an ordinary tube furnace. Put the weighed catalyst into it and pass in hydrogen. When the temperature reaches 380°C, start...

Embodiment 2

[0063] (1) Preparation of hydrogenation catalyst

[0064] Prepare a solution of 8.3g of nickel nitrate and 12.5g of pure water, weigh 10g of 60-80 mesh alumina particles, impregnate the two in equal volume, put them in a 40°C ultrasonic box for 2 hours, and then take them out at room temperature The environment was left to stand for 4 hours. After impregnation, continue to dry at 80°C, then bake in a muffle furnace at 450°C for 3 hours, and slowly drop to room temperature; prepare a solution with 0.13g of cerium nitrate and 0.13g of ruthenium nitrate and 12.5g of pure water, and mix with The above-mentioned roasted product was impregnated again in an equal volume at 40°C for 12 hours. After the second impregnation was completed, it was dried at 80°C, then put into a muffle furnace and roasted at 450°C for 2 hours, and then cooled to room temperature. Take out and set aside.

[0065] The catalyst needs to be activated by hydrogen before it can be used again. The activation us...

Embodiment 3

[0071] (1) Preparation of hydrogenation catalyst

[0072] Prepare a solution of 8.3g of nickel nitrate and 12.5g of pure water, weigh 10g of 60-80 mesh alumina particles, impregnate the two in equal volume, put them in a 40°C ultrasonic box for 2 hours, and then take them out at room temperature The environment was left to stand for 4 hours. After impregnation, continue to dry at 80°C, then bake in a muffle furnace at 450°C for 3 hours, and slowly drop to room temperature; prepare a solution with 0.13g of cerium nitrate and 0.13g of ruthenium nitrate and 12.5g of pure water, and mix with The above-mentioned roasted product was impregnated again in an equal volume at 40°C for 12 hours. After the second impregnation was completed, it was dried at 80°C, then put into a muffle furnace and roasted at 450°C for 2 hours, and then cooled to room temperature. Take out and set aside.

[0073] The catalyst needs to be activated by hydrogen before it can be used again. The activation us...

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Abstract

The invention provides a method for preparing o-toluic acid and phthalide from phthalic anhydride. The method comprises the following steps: carrying out a hydrogenation reaction on hydrogen and phthalic anhydride in the presence of a hydrogenation catalyst to prepare o-toluic acid and phthalide, wherein the reaction temperature is 120-180 DEG C, the reaction pressure is 1-6 MPa, and the mass ratio of the phthalic anhydride to the hydrogenation catalyst is (1:0.01)-(1:0.15). According to the method provided by the invention, selectivity of products of o-toluic acid and phthalide can be effectively controlled through control of reaction conditions.

Description

technical field [0001] The invention relates to a preparation method of chemical products, in particular to a method for preparing o-toluic acid and phthalide from phthalic anhydride. Background technique [0002] Phthalic anhydride is the abbreviation of phthalic anhydride, which is a cyclic anhydride formed by intramolecular dehydration of phthalic acid. It is an important raw material in chemical industry, especially for the manufacture of plasticizers. [0003] Phthalic anhydride is a white solid with molecular formula C 6 h 4 (CO) 2 O, molecular weight 148.11, melting point 131°C, boiling point 284°C, easy to sublimate, insoluble in cold water, easily soluble in hot water and hydrolyzed into phthalic acid, soluble in ethanol, benzene and pyridine, slightly soluble in ether. [0004] O-toluic acid, also known as 2-methylbenzoic acid or o-toluic acid, is white flammable prism or needle crystal at room temperature, molecular formula C 8 h 7 o 2 , molecular weight 136...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/083C07C63/04C07D307/88
CPCC07C51/083C07D307/88C07C63/04
Inventor 李婷吴园斌李拥军于洪锋娄云广杨文梁杨卫娟
Owner TANGSHAN XUYANG CHEM IND CO LTD
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