Method for producing 1,4-bis (dichloromethyl) tetrafluorobenzene
View Patent ↗A method for producing 1,4-bis(dichloromethyl)tetrafluorobenzene is disclosed, which is achieved by reacting tetrafluoroterephthaldehyde, SOCl 2 and organic solvents. In the synthesis of 1,4-bis(dichloromethyl)-tetrafluorobenzene by adding formamides as catalyst, there are remarkable advantages which include shortening the reaction time; simplifying the synthesizing steps and raising the yield of the product.
1. A method for producing 1,4-bis(dichloromethyl)-tetrafluorobenzene, comprising the following steps:
(a) mixing tetrafluoroterephthaldehyde, a catalyst and SOCl 2 with or without organic solvents to form a mixture, wherein the catalyst is formamides;
(b) heating the mixture;
(c) cooling the mixture, adding the mixture into water slowly, and letting the mixture separate into two layers;
(d) obtaining an organic layer from the layers of the mixture; and
(e) purifying the organic layer and removing the organic solvents and the catalyst in the organic layer and affording 1,4-bis(dichloromethyl)-tetrafluorobenzene.
2. The method as claimed in claim 1 , wherein the molar ratio of tetrafluoroterephthaldehyde to SOCl 2 is in the range from 2 to 20.
3. The method as claimed in claim 1 , wherein the weight ratio of the catalyst to tetrafluoroterephthaldehyde is in the range from 0.1 to 1.0.
4. The method as claimed in claim 1 , wherein the weight ratio of the organic solvent to tetrafluoroterephthaldehyde is in the range from 0 to 3.
5. The method as claimed in claim 1 , wherein the mixture is refluxed by heating in the step (b).
6. The method as claimed in claim 1 , wherein the mixture in the step (b) is heated until the temperature thereof rises to the range from 60 to 130° C.
7. The method as claimed in claim 1 , wherein the reaction time of the step (b) is in the range from 2 to 30 hours.
8. The method as claimed in claim 1 , wherein the mixture is cooled in the range from 0 to 60° C. in the step (c).
9. The method as claimed in claim 1 , wherein the mixture is added to iced water slowly in the step (c).
10. The method as claimed in claim 1 , wherein the organic solvent is at least one selected from the group consisting of toluene, chloroform, p-xylene, benzene, dioxane, 1,2-dichloroethane, tetrachloromathane, tetrahydrofuran, nitrobenzene, and o-dichlorobenzene.
11. The method as claimed in claim 1 , wherein the catalyst is N,N-dialkylformamide, and the alkyl group is a C 1 ˜C 7 alkyl group.
12. The method as claimed in claim 1 , wherein the catalyst is N,N-dimethylformamide (DMF), or N,N-diethylformamide (DEF).
13. The method as claimed in claim 1 , wherein the step (e) comprises the following steps:
(e1) adding an organic solvent and water (H 2 O) into the organic layer under stirring;
(e2) neutralizing the mixture;
(e3) isolating the organic layer and then concentrating the organic layer; and
(e4) cooling the organic layer to obtain a solid product.
14. The method as claimed in claim 13 , wherein the volume ratio of the organic solvent to water is in the range from 1 to 10 in the step (e1).
15. The method as claimed in claim 13 , wherein the organic solvent is dichloromethane in the step (e1).
16. The method as claimed in claim 13 , wherein the mixture is neutralized by concentrated ammonia in the step (e2).