Preparation method for 2,2-dichloro-1,2-dibrom-1,1-difluoroethane
What is Al technical title?
Al technical title is built by PatSnap Al team. It summarizes the technical point description of the patent document.
A technology of difluoroethane and trichloroethane, applied in 2, can solve problems such as being difficult to obtain, and achieve the effects of simple and easy method, mild reaction conditions, and easy-to-obtain raw materials
Inactive Publication Date: 2005-01-19
ZHEJIANG LANTIAN ENVIRONMENTAL PROTECTION HI TECH
View PDF1 Cites 3 Cited by
Summary
Abstract
Description
Claims
Application Information
AI Technical Summary
This helps you quickly interpret patents by identifying the three key elements:
Problems solved by technology
Method used
Benefits of technology
Problems solved by technology
This method raw material 2,2-dichloro-1,1-dibromo-1,2-difluoroethane is not easy to obtain
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more
Image
Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
Click on the blue label to locate the original text in one second.
Reading with bidirectional positioning of images and text.
Smart Image
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0025] 1. In a 500ml three-necked reaction flask equipped with a magnetic stirrer, a thermometer, a reflux condenser and a cooling condenser, drop into 240 grams of 25% NaOH aqueous solution and 1.0 gram of phase transfer catalyst tetrabutylammonium bromide, at a temperature of 20 to 20 169.5 grams of 2,2-difluoro-1,1,2-trichloroethane was added dropwise at 25°C, and the dropping time was controlled to be 2 hours. The content of the product 1,1-difluoro-2,2-dichloroethylene is 99.0% by weight, and 2,2-difluoro-1,1,2-trichloroethane is 1.0% by weight.
[0026] 2. In a 500ml three-necked reaction flask equipped with a magnetic stirrer, a thermometer and a reflux condenser, add 336 grams of liquid bromine, and dropwise add the 1,1-difluoro-2 , 268.7 grams of 2-dichloroethene, control the dropping time for 3 hours, after the dropping is completed, keep warm at 5-10°C for 2 hours, then raise the temperature to 50-55°C, and wash with 100ml of 5% NaOH aqueous solution for two times,...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more
PUM
Property
Measurement
Unit
boiling point
aaaaa
aaaaa
boiling point
aaaaa
aaaaa
Login to view more
Abstract
The invention relates to a preparation method for 2,2-dichloro-1,2-dibrom-1,1-difluoroethane from 1,1-difluorine-1,2,2-trichloroethane at the presence of its 0.5-2.0% quaternary ammonium salt or quaternary phosphonium salt phase transition catalyst, through hydrogen chloride removal under alkaline condition at 0-80 deg. C to prepare 1,1-difluorine-2,2-dichloroethylene, charging 1.0-1.5 mol weight of bromine for reaction at 0-50 deg. C.
Description
technical field [0001] The invention relates to a preparation method of fluorine-containing organic compound 2,2-dichloro-1,2-dibromo-1,1-difluoroethane. Background technique [0002] 2,2-Dichloro-1,2-dibromo-1,1-difluoroethane is a precursor for the synthesis of alkyl brominated difluoroacetates, which are intermediates for pharmaceutical products . [0003] So far, only German patent 2,245,372 has recorded the preparation of 2,2-dichloro-1,1-dibromo-1,2-difluoroethane by catalytic isomerization under the action of aluminum halide 1,2-Dibromo-1,1-difluoroethane method. The raw material 2,2-dichloro-1,1-dibromo-1,2-difluoroethane for this method is not easily available. Contents of the invention [0004] The present invention aims at the deficiencies of the prior art, and develops a 2,2-dichloro-1,1-difluoro-1,2,2-trichloroethane through two steps of dehydrochlorination reaction and bromine addition reaction. - The method...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more
Application Information
Patent Timeline
Application Date:The date an application was filed.
Publication Date:The date a patent or application was officially published.
First Publication Date:The earliest publication date of a patent with the same application number.
Issue Date:Publication date of the patent grant document.
PCT Entry Date:The Entry date of PCT National Phase.
Estimated Expiry Date:The statutory expiry date of a patent right according to the Patent Law, and it is the longest term of protection that the patent right can achieve without the termination of the patent right due to other reasons(Term extension factor has been taken into account ).
Invalid Date:Actual expiry date is based on effective date or publication date of legal transaction data of invalid patent.
Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C07C17/04C07C17/35C07C19/14
Inventor 徐卫国陈先进
Owner ZHEJIANG LANTIAN ENVIRONMENTAL PROTECTION HI TECH
Login to view more