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Method for preparing 2,7-dicarboxylic-3,6-diacid naphthalinum 3,6-naphthalenedicarboxylate

A technology of dihydroxynaphthalene and naphthalene diacid, which is applied in the field of preparation of aromatic hydroxycarboxylic acids, can solve the problems of difficult operation, fewer synthesis steps, and more steps, and achieve the effect of less synthesis steps, easy operation, and low cost

Inactive Publication Date: 2012-07-04
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Compared with the two routes, the first route introduces carboxyl groups, and the synthesis steps are less, which is easy to implement; the second route has a shorter reaction time overall, but it takes several steps to introduce carboxyl groups, which is difficult to operate, with many steps and high cost.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Add 5 grams of 2,7-dihydroxynaphthalene to an autoclave equipped with an electric stirring device, add 80 milliliters of methanol solution containing 5 grams of potassium hydroxide under nitrogen protection, then evacuate and fill with nitrogen three times to get rid of oxygen in the solution , stirred at room temperature for 12 hours under nitrogen protection. Then 100 ml of hydrogenated terphenyl was added, and after the temperature was raised to 100° C., the methanol and volatile small molecules in the autoclave were vacuumed out. Raise the temperature to 270°C, feed carbon dioxide gas, then raise the temperature to 310°C, and react for 4 hours under the condition of carbon dioxide pressure of 4Mpa. After cooling to room temperature, pour out the hydrogenated terphenyl, dissolve the residual solid with hot water at 80-100°C, filter with suction, acidify the filtrate to pH 1-3 with concentrated hydrochloric acid (35%, W / W), filter with suction again, and then Dissolv...

Embodiment 2

[0021] Add 10 grams of 2,7-dihydroxynaphthalene to an autoclave equipped with an electric stirring device, add 160 ml of methanol solution containing 10 grams of potassium hydroxide under nitrogen protection, then evacuate and fill with nitrogen three times to eliminate oxygen in the solution , stirred at room temperature for 12 hours under nitrogen protection. Then 100 ml of hydrogenated terphenyl was added, and after the temperature was raised to 100° C., methanol and volatile small molecules in the autoclave were vacuumed out. Raise the temperature to 275°C, feed carbon dioxide gas, then raise the temperature to 316°C, and react for 4 hours under the condition of carbon dioxide pressure 6Mpa. After cooling to room temperature, pour out the hydrogenated terphenyl, dissolve the residual solid with hot water at 80-100°C, filter with suction, acidify the filtrate to pH 1-3 with concentrated hydrochloric acid (37%, W / W), filter with suction again, and then Dissolve with acetone...

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Abstract

The invention provides a method for preparing 2,7-dicarboxylic-3,6-naphthalenedicarboxylate. The method comprises the following steps: firstly, converting 2,7-dicarboxylic naphthalinum into 2,7-dicarboxylic potassium salt by alkalization; then adding a high-temperature heat medium of hydrogenated terphenyl, obtaining naphtholate; afterwards introducing carbon dioxide, reacting for 4 hours at the temperature of 300-330 DEG C and the pressure of 4-6MPa and obtaining a yellow solid product of the 2,7-dicarboxylic-3,6-naphthalenedicarboxylate by the post-treatment steps of dissolving, filtering, drying and the like. The invention has less synthesis steps, easy operation and low cost. Compared with the prior art, the yield is enhanced by more than 4 times.

Description

technical field [0001] The invention relates to a method for preparing aromatic hydroxycarboxylic acid, in particular to a method for preparing 2,7-dihydroxy-3,6-naphthalene diacid by using liquid-gas two-phase Kolbe-Schmitt reaction. Background technique [0002] Aromatic hydroxycarboxylic acids can be obtained by reacting aromatic hydroxy compounds with carbon dioxide by the known Kolbe-Schmitt reaction. Taking 2,4-dihydroxy-1,5-benzenedicarboxylic acid as an example, under the alkaline condition of potassium bicarbonate, the temperature is 110°C, the pressure of carbon dioxide is 0.3Mpa, the reaction is 3 hours, and the product yield is as high as 99.7%. Under the alkaline conditions of potassium carbonate, the temperature is 200° C., the carbon dioxide pressure is 0.3 Mpa, and the reaction time is 4 hours, a yield of 93% is also obtained (see patent DE3832076, 1932-06-08). For aromatic hydroxy compounds based on the naphthalene ring, although the traditional Kolbe-Schmi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C65/11C07C51/15
CPCY02P20/141
Inventor 袁立华冯文岳亚荣张鹏辉张路杨永安蒲文臣
Owner SICHUAN UNIV
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