Method for catalyzing and synthesizing bibasic carboxylic ester by potassium hydrogen sulfate

A technology of potassium bisulfate catalysis and dibasic carboxylate, which is applied in the preparation of carboxylate, chemical instruments and methods, and the preparation of organic compounds. Problems such as complicated regeneration and complicated post-treatment process can be achieved to facilitate long-term operation, easy storage and transshipment, and reduce the loss of chemical raw materials and products.

Inactive Publication Date: 2007-12-26
NANJING UNIV OF SCI & TECH
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Problems solved by technology

The synthesis of carboxylic acid esters in industry generally adopts the esterification synthesis method using concentrated sulfuric acid as a catalyst. Complex processing
In order to overcome the above-mentioned shortcomings, a variety of environment-friendly catalysts have been developed, such as acidic resins, heteropolyacids, ferric chloride, solid superacids, biological enzymes, etc., which have achieved good esterification effects, but these methods are still There are the following problems: the activation and regeneration of acid resin is complicated; the preparation of heteropoly acid and solid superacid is complicated, and the production cost is high; ferric chloride is easy to absorb moisture, which is not convenient to use and store; In addition, although the above method can achieve a higher yield due to the use of water-carrying agents, it increases raw material consumption, proliferates the production process, and increases production costs.

Method used

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  • Method for catalyzing and synthesizing bibasic carboxylic ester by potassium hydrogen sulfate
  • Method for catalyzing and synthesizing bibasic carboxylic ester by potassium hydrogen sulfate
  • Method for catalyzing and synthesizing bibasic carboxylic ester by potassium hydrogen sulfate

Examples

Experimental program
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Effect test

Embodiment 1

[0024] Embodiment 1: the synthesis of dimethyl adipate

[0025] In a three-necked flask equipped with a thermometer and a reflux condenser, add 14.61g of adipic acid (0.1mol), 20mL of anhydrous methanol (0.5mol), 4g (0.3mol) of potassium hydrogensulfate, and heat the oil bath to 100°C. The reaction was carried out under reflux, the progress of the reaction was monitored by TLC, and the reaction was completed after 2 hours. After cooling, the reactant is filtered, the filter cake is washed with methanol, and the recovered potassium bisulfate can be reused after being dried. Combine the filtrate and washing liquid, evaporate unreacted methanol in the filtrate, methanol can be recycled, and the residue is the crude product of dimethyl adipate. The crude product is distilled under reduced pressure and collected at 115-117°C / 1.73 The fraction of KPa can obtain a colorless transparent liquid product with a yield of 98.55%, and a purity of 98.99% through gas chromatography detection...

Embodiment 2

[0033] Embodiment 2: the synthesis of diethyl adipate

[0034] In a three-necked flask equipped with a thermometer and a reflux condenser, add 14.61g of adipic acid (0.1mol), 30mL of absolute ethanol (0.5mol), and 4g of potassium bisulfate, heat the oil bath to 80°C, and reflux for 2 hours Finish. After cooling, the reactant is filtered, the filter cake is washed with ethanol, and the recovered potassium bisulfate can be reused after being dried. Combine the filtrate and washing liquid, evaporate the unreacted ethanol in the filtrate, the ethanol can be recycled, and the residue is the crude product of diethyl adipate. The crude product is then distilled under reduced pressure to obtain a colorless transparent liquid product 19.6 g, yield 97.13%.

Embodiment 3

[0035] Embodiment 3: the synthesis of n-butyl adipate

[0036] In a three-necked flask equipped with a thermometer and a reflux condenser, add 7.31g of adipic acid (0.05mol), 23mL of n-butanol (0.25mol), and 2g of potassium bisulfate, heat the oil bath to 120°C, and reflux for 4 hours Finish. After cooling, the reactant is filtered, the filter cake is washed with n-butanol alcohol, and the recovered potassium bisulfate can be reused after being dried. Combine the filtrate and washing liquid, steam the unreacted n-butanol alcohol in the filtrate, the n-butanol alcohol can be recycled, and the residue is the crude product of dimethyl adipate, and the crude product is then distilled under reduced pressure, finally 12.47 g of a colorless transparent liquid product was obtained with a yield of 95.90%.

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Abstract

This invention discloses a method for synthesizing dicarboxylate with KHSO4 as the catalyst. The method comprises: adding aromatic or aliphatic dicarboxylic acid and monohydric alcohol into a reaction container, adding KHSO4 as the catalyst for esterification reaction, stirring, heating, and reacting under refluxing to obtain aromatic or aliphatic dicarboxylate. KHSO4 is inorganic solid powder, and has a low solubility in organic solvent, thus can be separated by filtration after reaction. The KHSO4 catalyst thus has such advantages as no contamination to the product, convenient product post treatment, high product purity, low corrosion to apparatus, high catalytic activity after reaction, repeated use by filtration, drying and recovery, easy storage and transportation, and high safety.

Description

a technical field [0001] The present invention relates to a kind of synthetic method of carboxylic acid ester, particularly a kind of method that uses potassium bisulfate as catalyst to synthesize dibasic carboxylic acid ester. Two background technology [0002] The general formula (I) of dicarboxylic acid ester is as follows: [0003] [0004] Wherein A represents an aliphatic group with 0-20 carbon atoms or a carbon chain containing a benzene ring, and n represents 0-6. [0005] Aliphatic or aromatic dicarboxylic acid esters are important basic chemical raw materials and are widely used in industry. The synthesis of carboxylic acid esters in industry generally adopts the esterification synthesis method using concentrated sulfuric acid as a catalyst. The processing technology is complicated. In order to overcome the above-mentioned shortcomings, a variety of environment-friendly catalysts have been developed, such as acidic resins, heteropolyacids, ferric chloride, so...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C69/34C07C69/612C07C67/08B01J27/055
Inventor 方志杰申涛姜宇华方韬
Owner NANJING UNIV OF SCI & TECH
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