Title:
PREPARATION PROCESS FOR CATALYTIC SYNTHESIS OF 2,4-DICHLOROPHENOXYACETIC ACID
Document Type and Number:
WIPO Patent Application WO/2024/060737
Kind Code:
A1
Abstract:
Provided is a preparation process for the catalytic synthesis of 2,4-dichlorophenoxyacetic acid. Water is used as a solvent. Chloroacetic acid, sodium hydroxide or sodium carbonate, and 2,4-dichlorophenol are used as initial starting materials. By means of a neutralization reaction, a sodium chloroacetate solution is first obtained. 2,4-dichlorophenol is then reacted with sodium hydroxide to produce a sodium 2,4-dichlorophenoxide solution. A proper amount of catalyst Na2O/SiO2 is added, and under an alkaline condition, the sodium 2,4-dichlorophenoxide solution and the sodium chloroacetate solution are subjected to a condensation reaction to obtain a sodium 2,4-dichlorophenoxyacetate crude product. The sodium 2,4-dichlorophenoxyacetate crude product is then dissolved in water and acidified with hydrochloric acid to obtain the 2,4-dichlorophenoxyacetic acid product. The catalyst is adopted to solve a solvation effect. After catalysis by the catalyst, the conversion rate and yield of the product are improved, and side reactions are reduced, so that the conversion rate and yield of the product can be improved, the product purity is high, the conditions are mild, the starting materials during the process can also be recycled, the catalyst can be recycled, and the preparation process is suitable for large-scale industrial production.
Inventors:
LIU CHANG (CN)
TIAN YIQUN (CN)
DENG SHENCHUAN (CN)
HU FUCHAO (CN)
HE YUSHA (CN)
WANG YUTING (CN)
PENG CHUNXUE (CN)
CAO JIE (CN)
ZENG SHILIU (CN)
ZHANG RUI (CN)
QIN LIZHONG (CN)
LIU SANLIU (CN)
TIAN YIQUN (CN)
DENG SHENCHUAN (CN)
HU FUCHAO (CN)
HE YUSHA (CN)
WANG YUTING (CN)
PENG CHUNXUE (CN)
CAO JIE (CN)
ZENG SHILIU (CN)
ZHANG RUI (CN)
QIN LIZHONG (CN)
LIU SANLIU (CN)
Application Number:
PCT/CN2023/102424
Publication Date:
March 28, 2024
Filing Date:
June 26, 2023
Export Citation:
Assignee:
HUBEI TAISHENG CHEMICAL CO LTD (CN)
International Classes:
C07C59/70; B01J20/04; B01J20/06; B01J20/08; B01J20/10; B01J37/08; C07C51/02
Foreign References:
| CN116120168A | 2023-05-16 | |||
| CN108503536A | 2018-09-07 | |||
| CN108503527A | 2018-09-07 | |||
| CN108503526A | 2018-09-07 | |||
| CN113336616A | 2021-09-03 | |||
| CN101391753A | 2009-03-25 |
Other References:
ZOU, PING: "Experiment 27 Preparation of 2,4-dichlorophenoxyacetic Acid (Herbicide)", ORGANIC CHEMISTRY EXPERIMENT, 31 January 2005 (2005-01-31)
Attorney, Agent or Firm:
YICHANG THREE GORGES PATENT (CN)
Download PDF:
Previous Patent: DOOR OPENING AND CLOSING DEVICE AND ELECTRICAL APPARATUS
Next Patent: OVER-DRIVER APPARATUS AND METHOD, AND DISPLAY APPARATUS
Next Patent: OVER-DRIVER APPARATUS AND METHOD, AND DISPLAY APPARATUS