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ChemicalBook CAS DataBase List 4,4'-Oxybisbenzoic acid
2215-89-6

4,4'-Oxybisbenzoic acid synthesis

14synthesis methods
-

Yield:2215-89-6 95.9%

Reaction Conditions:

with potassium carbonate in sulfolane at 143 - 145; for 16 h;Reagent/catalyst;Solvent;Temperature;

Steps:

1-4 Example 1
A 500 ml four-necked flask was charged with 120 g of sulfolane, Add 31.3 g of 4-chlorobenzoic acid and 29.0 g of 4-hydroxybenzoic acid with stirring, 15.2 g of potassium carbonate was added, and the temperature was raised to 143 to 145 ° C with stirring, and the reaction was performed. Centralized sampling analysis after 16 hours of reaction, The content of 4-chlorobenzoic acid is less than 0.5% (GC normalized content) as the end point of the reaction. If the end of the reaction is not reached, Continue to incubate the reaction at 143 145 , Until the content of 4-chlorobenzoic acid is less than 0.5% (GC normalized content). After the reaction was completed, the temperature was lowered below 100 ° C, and 250 ml of water was added dropwise. With the addition of water, a large amount of solids precipitated. After the water is added, stir at 40-50 ° C for one hour (the speed is 100-150r / min), filter, and wash the filter cake with 100ml of water (water temperature is about 40 ° C). After drying, 49.5 g of product was obtained with a content of 99.4% (normalized content by HPLC) and a yield of 95.9%. The aqueous solution containing sulfolane was dehydrated under reduced pressure, and the distillation temperature reached 105 ° C (vacuum degree is 20-30mmHg). After the dehydration was completed, a mixture of salt (mainly potassium chloride) and sulfolane was obtained. The temperature was reduced to 50 ° C, and filtered to obtain sulfolane. 106g, the recovered sulfolane contains 4-hydroxybenzoic acid. After analyzing its content by gas spectroscopy, the amount of 4-hydroxybenzoic acid to be charged is determined after conversion. Distilled water can also be applied.

References:

Shenyang Chemical Institute Co., Ltd.;Guo Lin;Yin Yongbo;Song Lifeng;Sun Chaohui;Tang Yong CN104311408, 2019, B Location in patent:Paragraph 0020-0033

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