GB2175299A - Isolation of alkali metal 2,4-dichlorophenolate and 2,4-dichlorophenol from a mixture of chlorophenols - Google Patents
Isolation of alkali metal 2,4-dichlorophenolate and 2,4-dichlorophenol from a mixture of chlorophenols Download PDFInfo
- Publication number
- GB2175299A GB2175299A GB8512199A GB8512199A GB2175299A GB 2175299 A GB2175299 A GB 2175299A GB 8512199 A GB8512199 A GB 8512199A GB 8512199 A GB8512199 A GB 8512199A GB 2175299 A GB2175299 A GB 2175299A
- Authority
- GB
- United Kingdom
- Prior art keywords
- mixture
- dichlorophenol
- toluene
- dichlorophenolate
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000203 mixture Substances 0.000 title claims abstract description 151
- HFZWRUODUSTPEG-UHFFFAOYSA-N 2,4-dichlorophenol Chemical compound OC1=CC=C(Cl)C=C1Cl HFZWRUODUSTPEG-UHFFFAOYSA-N 0.000 title claims abstract description 55
- 229910052783 alkali metal Inorganic materials 0.000 title claims abstract description 37
- VGVRPFIJEJYOFN-UHFFFAOYSA-N 2,3,4,6-tetrachlorophenol Chemical class OC1=C(Cl)C=C(Cl)C(Cl)=C1Cl VGVRPFIJEJYOFN-UHFFFAOYSA-N 0.000 title claims abstract description 31
- -1 alkali metal 2,4-dichlorophenolate Chemical class 0.000 title claims abstract description 29
- 238000002955 isolation Methods 0.000 title description 2
- 238000001035 drying Methods 0.000 claims abstract description 58
- 238000009835 boiling Methods 0.000 claims abstract description 55
- 239000002244 precipitate Substances 0.000 claims abstract description 47
- 238000000034 method Methods 0.000 claims abstract description 37
- 239000007864 aqueous solution Substances 0.000 claims abstract description 34
- 150000004945 aromatic hydrocarbons Chemical class 0.000 claims abstract description 16
- 239000003513 alkali Substances 0.000 claims abstract description 13
- DNIAPMSPPWPWGF-GSVOUGTGSA-N (R)-(-)-Propylene glycol Chemical compound C[C@@H](O)CO DNIAPMSPPWPWGF-GSVOUGTGSA-N 0.000 claims abstract description 10
- 238000001816 cooling Methods 0.000 claims abstract description 6
- 239000002253 acid Substances 0.000 claims abstract description 4
- 229910052500 inorganic mineral Inorganic materials 0.000 claims abstract description 4
- 239000011707 mineral Substances 0.000 claims abstract description 4
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 294
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 claims description 21
- 150000001340 alkali metals Chemical class 0.000 claims description 8
- 239000008096 xylene Substances 0.000 claims description 3
- 150000003738 xylenes Chemical class 0.000 claims description 3
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 71
- UMPSXRYVXUPCOS-UHFFFAOYSA-N 2,3-dichlorophenol Chemical compound OC1=CC=CC(Cl)=C1Cl UMPSXRYVXUPCOS-UHFFFAOYSA-N 0.000 description 54
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 45
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 42
- 239000000047 product Substances 0.000 description 35
- ISPYQTSUDJAMAB-UHFFFAOYSA-N 2-chlorophenol Chemical compound OC1=CC=CC=C1Cl ISPYQTSUDJAMAB-UHFFFAOYSA-N 0.000 description 33
- WXNZTHHGJRFXKQ-UHFFFAOYSA-N 4-chlorophenol Chemical compound OC1=CC=C(Cl)C=C1 WXNZTHHGJRFXKQ-UHFFFAOYSA-N 0.000 description 28
- HOLHYSJJBXSLMV-UHFFFAOYSA-N 2,6-dichlorophenol Chemical compound OC1=C(Cl)C=CC=C1Cl HOLHYSJJBXSLMV-UHFFFAOYSA-N 0.000 description 26
- 238000007796 conventional method Methods 0.000 description 25
- KSLKDKJNBJAMEG-UHFFFAOYSA-M potassium;2-chlorophenolate Chemical class [K+].[O-]C1=CC=CC=C1Cl KSLKDKJNBJAMEG-UHFFFAOYSA-M 0.000 description 25
- LINPIYWFGCPVIE-UHFFFAOYSA-N 2,4,6-trichlorophenol Chemical compound OC1=C(Cl)C=C(Cl)C=C1Cl LINPIYWFGCPVIE-UHFFFAOYSA-N 0.000 description 24
- 238000001914 filtration Methods 0.000 description 24
- GQFIWFPBDXSASA-UHFFFAOYSA-M sodium;2-chlorophenolate Chemical class [Na+].[O-]C1=CC=CC=C1Cl GQFIWFPBDXSASA-UHFFFAOYSA-M 0.000 description 24
- AWMXXHDQRKEBOT-UHFFFAOYSA-M potassium;2,4-dichlorophenolate Chemical compound [K+].[O-]C1=CC=C(Cl)C=C1Cl AWMXXHDQRKEBOT-UHFFFAOYSA-M 0.000 description 23
- 238000010992 reflux Methods 0.000 description 23
- BYOIUZNBVLCMNV-UHFFFAOYSA-M sodium;2,4-dichlorophenolate Chemical compound [Na+].[O-]C1=CC=C(Cl)C=C1Cl BYOIUZNBVLCMNV-UHFFFAOYSA-M 0.000 description 22
- 239000003960 organic solvent Substances 0.000 description 11
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 9
- CMQCNTNASCDNGR-UHFFFAOYSA-N toluene;hydrate Chemical compound O.CC1=CC=CC=C1 CMQCNTNASCDNGR-UHFFFAOYSA-N 0.000 description 9
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- URLKBWYHVLBVBO-UHFFFAOYSA-N Para-Xylene Chemical group CC1=CC=C(C)C=C1 URLKBWYHVLBVBO-UHFFFAOYSA-N 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 5
- 229910052700 potassium Inorganic materials 0.000 description 5
- 239000011591 potassium Substances 0.000 description 5
- 239000000243 solution Substances 0.000 description 5
- IZUPBVBPLAPZRR-UHFFFAOYSA-N pentachlorophenol Chemical compound OC1=C(Cl)C(Cl)=C(Cl)C(Cl)=C1Cl IZUPBVBPLAPZRR-UHFFFAOYSA-N 0.000 description 4
- 239000002351 wastewater Substances 0.000 description 4
- HFZWRUODUSTPEG-UHFFFAOYSA-M 2,4-dichlorophenolate Chemical compound [O-]C1=CC=C(Cl)C=C1Cl HFZWRUODUSTPEG-UHFFFAOYSA-M 0.000 description 3
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 3
- 238000000605 extraction Methods 0.000 description 3
- 150000004707 phenolate Chemical class 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- 125000003118 aryl group Chemical group 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 239000004009 herbicide Substances 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 239000012044 organic layer Substances 0.000 description 2
- 239000000575 pesticide Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- FSNZXGJIGGFBGU-UHFFFAOYSA-N 1,2,4-trichlorocyclohexa-2,4-dien-1-ol Chemical compound ClC1(CC=C(C=C1Cl)Cl)O FSNZXGJIGGFBGU-UHFFFAOYSA-N 0.000 description 1
- TYNIJIXWHNNKNQ-UHFFFAOYSA-N 1,4-xylene;hydrate Chemical compound O.CC1=CC=C(C)C=C1 TYNIJIXWHNNKNQ-UHFFFAOYSA-N 0.000 description 1
- 239000005631 2,4-Dichlorophenoxyacetic acid Substances 0.000 description 1
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- CYTYCFOTNPOANT-UHFFFAOYSA-N Perchloroethylene Chemical group ClC(Cl)=C(Cl)Cl CYTYCFOTNPOANT-UHFFFAOYSA-N 0.000 description 1
- VEFXTGTZJOWDOF-UHFFFAOYSA-N benzene;hydrate Chemical compound O.C1=CC=CC=C1 VEFXTGTZJOWDOF-UHFFFAOYSA-N 0.000 description 1
- 239000001110 calcium chloride Substances 0.000 description 1
- 229910001628 calcium chloride Inorganic materials 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000005660 chlorination reaction Methods 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 239000011363 dried mixture Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- BRMNIPUJQIHQIE-UHFFFAOYSA-N ethanol;toluene;hydrate Chemical compound O.CCO.CC1=CC=CC=C1 BRMNIPUJQIHQIE-UHFFFAOYSA-N 0.000 description 1
- 239000000374 eutectic mixture Substances 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000825 pharmaceutical preparation Substances 0.000 description 1
- 229940031826 phenolate Drugs 0.000 description 1
- 150000002989 phenols Chemical class 0.000 description 1
- VBEFOPVBFWVLJM-UHFFFAOYSA-M potassium;2,3-dichlorophenolate Chemical compound [K+].[O-]C1=CC=CC(Cl)=C1Cl VBEFOPVBFWVLJM-UHFFFAOYSA-M 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000011112 process operation Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- FAPWRFPIFSIZLT-UHFFFAOYSA-M sodium chloride Inorganic materials [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 1
- NESLWCLHZZISNB-UHFFFAOYSA-M sodium phenolate Chemical class [Na+].[O-]C1=CC=CC=C1 NESLWCLHZZISNB-UHFFFAOYSA-M 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
- C07C37/70—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment
- C07C37/84—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment by crystallisation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/01—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by replacing functional groups bound to a six-membered aromatic ring by hydroxy groups, e.g. by hydrolysis
- C07C37/055—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by replacing functional groups bound to a six-membered aromatic ring by hydroxy groups, e.g. by hydrolysis the substituted group being bound to oxygen, e.g. ether group
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/64—Preparation of O-metal compounds with O-metal group bound to a carbon atom belonging to a six-membered aromatic ring
- C07C37/66—Preparation of O-metal compounds with O-metal group bound to a carbon atom belonging to a six-membered aromatic ring by conversion of hydroxy groups to O-metal groups
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
- C07C37/685—Processes comprising at least two steps in series
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
- C07C37/70—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment
- C07C37/72—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment by liquid-liquid treatment
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
A process for isolating an alkali-metal 2,4-dichlorophenolate and 2,4-dichlorophenol from a mixture of chlorophenols comprises reacting a mixture of chlorophenols with an aqueous solution of an alkali in the presence of an aromatic hydrocarbon with a boiling temperature within the range of from 80 to 150 DEG C or a mixture thereof with an aliphatic alcohol. The process is conducted at a mass ratio of the mixture of chlorophenols to the aromatic hydrocarbon of 1:1-3 respectively, or at a mass ratio of the mixture of chlorophenols, aromatic hydrocarbon and aliphatic alcohol equal to 1:1-3:0.05-0.2 respectively till a mixture containing the alkali metal chlorophenolates is formed which mixture is subjected to an azeotropic drying and then cooling to recover the alkali-metal 2,4-dichlorophenolate as a precipitate which, when necessary, is treated with a mineral acid to yield 2,4-dichlorophenol.
Description
SPECIFICATION
Process for isolating alkali metal 2,4-dichlorophenolate and 2,4-dichlorophenol from a mixture of chlorophenols
The present invention relates to a process for isolating an alkali metal 2,4-dichlorophenolate and 2,4-dichlorophenol from a mixture of chlorophenols which are useful in the production of pesticides and pharmaceutical preparations.
The starting material for the synthesis of, for example, mass- scale herbicides of the groups 2,4-D; 2,4-DP; 2,4-DM is a commercial mixture of chlorophenols containing 2,4-dichlorophenol or 2,4-dichlorophenolates of alkali metals prepared on the basis of the former. The commercial mixture of chlorophenols is produced by chlorination of a melt of phenols by gaseous chlorine. The content of 2,4-dichlorophenol in the mixture does not exceed 76-94%, while the main impurities are 2,6dichlorophenol, 2,4,6-trichlorophenol, 2-chlorophenol and 4-chlorophenol.
The use of a commercial mixture of chlorophenols in the production of herbicides results in a lower quality of the latter, overrated consumption of hardly available and expensive reactants, in the formation of a large quantity of hardly-utilizable waste products and effluents.
All this points to the urgent character of problems assaciated with the development of processes for recovering and purification of 2,4dichlorophenol or an alkali metal phenolate thereof from a commercial mixture of chlorophenols.
Known in the art is a process for recovering 2,4dichlorophenol from a mixture of chlorophenols by crystallization of a melt in the presence of water and an electrolyte-sodium chloride or calcium chloride (cf. USSR Inventor's Certificate No. 406824).
The process is based on the formation of eutectic mixtures with low-melting temperatures. First crystallized is 2,4-dichlorophenol, while low-melting mixtures of chlorophenols for a thin-film envelope over the surface of the formed crystals. This film is removed from the crystal surface by way of compression under the pressure of 24 MPa for 10 minutes or by centrifugation (at the centrifuge rotation speed of 2,850 r.p.m.). The yield of 2,4-dichlorophenol is 80% at the purity of 98-99% The yield of 2,4-dichlorophenol can be increased up to 97% by way of recovering thereof from liquid equtectic mixtures by alkali extraction.
This process is characterized by the formation of a great amount of chemically contaminated waste waters, by a low yield of the desired product after the crystallization stage, as well as by sophisticated process equipment.
Known in the art is a process for recovering 2,4dichlorophenol from a mixture of chlorophenols containing 2-chlorophenol in an amount of from 0.1 to 0.5% by mass by way of a multi-stage alkali extraction in an organic solvent, for example perchloroethylene (cf. USSR Inventor's Certificate
No. 250154).
This method of separation is based on a conventional principle, namely on the use of a different acidity of isomeric chlorophenols.
In this prior art process use is made of a 1N aqueous solution of an alkali. This process makes it possible to obtain up to 85% of 2,4-dichlorophenol with a purity of up to 99% by mass, but the mixture of chlorophenols should not contain more than 0.5% by mass of 2-chlorophenol having acidity close' to that of 2,4-dichlorophenol. Moreover, the process features the use of a sophisticated equipment; a large amount of chemically contaminated waste waters is formed therein due to the use of a diluted alkali solution as an extraction agent.
It is an--object of the present invention to provide such a process for isolating an alkali-metal 2,4dichlorophenolate and 2,4-dichlorophenol from a mixture of chlorophenols which would make it possible to increase the yield and improve the purity of the desired product.
It is another object of the present invention to simplify the process equipment simultaneously with reducing the amount of chemically contaminated waste waters.
This object is accomplished by a process for isolating 2,4-dichlorophenolate of an alkali metal and 2,4-dichlorophenol from a mixture of chalorophenols by reacting the mixture of chlorophenols with an aqueous alkali solution in the presence of an organic solvent, characterized in that as the organic solvent an aromatic hydrocarbon is used having boiling temperature within the range of from 80 to 150"C or a mixture thereof with an aliphatic alcohol and the process is conducted at a mass ratio of the mixture of chlorophenols and the aromatic hydrocarbon of 1:1-3 respectively, or at a ratio of the mixture of chlorophenols, aromatic hydrocarbon and the aliphatic alcohol of 1:1-3::0.05-0.2 respectively till the formation of a mixture containing the alkali metal chlorophenolates whioh is then subjected to an azeotropic drying and cooling, followed by precipitation of the alkali metal 2,4dichlorophenolate which, when necessary, is treated with a mineral acid to form 2,4-dichlorophenol.
The process according to the present invention ensures the isolation of the desired products with a purity of up to 99% by mass and with a yield of up to 95% owing to the use of an aromatic hydrocarbon or a mixture thereof with an aliphati alcohol selectively dissolving isomeric phenolates of the alkali metal.
It is advisable, to improve yield and quality of the desired product, that the cooling process be conducted at a temperature within the range of from 10 to 50"C and the mixture be kept at this temperature for 0.08 to 2 hours. To reduce the amount of chemically contaminated waste waters it is desirable to use a 10-50% aqueous solution of an alkali.
It is preferable to use, as the aromatic hydrocarbon, benzene, toluene and isomeric xylenes and, as the aliphatic alcohol, C2 - C4 - alcohols.
These organic solvents make it possible to conduct the process operations under mild conditions which enable a simple process technology and equipment employed. In the azeotropic drying isomeric phenolates of the alkali metal are not resinified, thus contributing to a fuller recovery of the alkali metal 2,4-di-chlorophenolate and to the possibility of a further use of the remaining phenolates of the alkali meta, for example in the production of penta-chlorophenol.
The process for producing an alkali metal 2,4dichlorophenolate and 2,4-dichlorophenol from a mixture of chlorophenols is effected in the following manner.
A mixture of chlorophenols containing (% by mass): 76-94 of 2,4-dichlorophenol, 2-20 of 2,6dichlorophenol, 2-10 of 2,4,6-trichlorophenol, 0.01-1 of 2-chlorophenol, 0.01-1 of 4-chlorophenol is treated with an equimolar amount of an aqueous alkali solution in the presence of an organic solvent. As the aqueous solution of the alkali sodium hydroxide or potassium hydroxide are used which are the most inexpensive products readily available in the industry and employed in the production of sodium and potassium, 2,4-dichlorophenolates valuable raw materials in the production of, for example, pesticides. In the process according to the present invention the alkalis are used in a high concentration to reduce the amount of chemically contaminated effluents and increase the product output from a unit working volume of the apparatus.The process of interaction of the mixture of chlorophenols and potassium hydroxide is conducted in the presence of an aromatic hydrocarbon having its boiling temperature within the range of from 80 to 1500C at a mass ratio thereof to the mixture of chlorophenols of 1-3:1 respectively to be chosen depending on the yield and quality of the desired product. When an aqueous solution of sodium hydroxide is used, as the organic solvent an aromatic hydrocarbon and an aliphatic alcohol are employed in a mass ratio of 1-3:0.05-0.2:1 to the mixture of chlorophenols.
We have found that individual alkali-metal chlorophenolates feature different solubility in aromatic hydrocarbons and in mixtures thereof with aliphatic alcohols. The temperature elevation provides different effects on the solubility of alkalimetal chlorophenolates in these solvents.
It follows from the foregoing, that through selection of organic solvents and process parameters an alkali-metal 2,4 dichlorophenolate can be recovered from a mixture of chlorophenolates of an alkali metal with a high yield and purity of up to 99% by mass.
As the aromatic hydrocarbon benzene, toluene, isomeric xylenes are employed; as the aliphatic alcohol - C2 -C4 -alcohols.
The resulting mixture containing the alkali-metal chlorophenolates is subjected to an azeotropic drying, i.e. water is distilled in the form of an azeotropic mixture organic solvent-water.
After condensation of vapours of the azeotropic mixture the organic layer is recycled into the process, while the aqueous layer is either drained into a sewerage system or delivered to the preparation of an aqueous solution of the starting alkali. Temperature during the process of azeotropic drying is maintained equal to the boiling temperature of the azeotropic mixture: aromatic hydrocarbon-water or the mixture aromatic hydrocarbon-aliphatic alcohol-water.
After distilling-off water the mixture of the alkalimetal chlorophenolates in the organic solvent is cooled to a temperature within the range of from 10 to 500C, maintained at this temperature for 0.08 to 2 hours and the precipitate of the alkali metal 2,4-dichlorophenolate is separated. Cooling of the mixture of the alkali-metal chlorophenolate in the organic solvent to a temperature below 10 C impairs purity of the desired product - alkali metal 2,4-dichlorophenolate, while temperature elevation above 50"C lowers the desired product yield due to an increased solubility of the alakli metal chlorophenolates in organic solvents at elevated temperatures.
The residence of the dried mixture of the alkalimetal chlorophenolates in organic solvents at a given temperature for a period of less than 0.08 hour results in an impaired purity of the recovered alkali-metal 2,4-dichlorophenolate and in a reduced yield thereof. Extension of the residence tinie above 2 hours does not provide any substantial influence on both yield and quality of the desired product.
To increase the yield of the alkali-metal 2,4-dichlorophenolate, the solution obtained after separation of the precipitate and containing isomeric chlorophenolates of the alkali metal can be subjected to a further treatment. It is evaporated and cooled following the above-described procedure.
The alkali-metal 2,4-dichlorophenolate with a purity of 92-94% by mass precipitates and then it is recycled to the stage of azeotropic drying, while the remaining solution containing isomeric chlorophenolates of the alkali metal can be used in the production of penta-chlorophenol. In this mode of the process arrangement the yield of the alkalimetal 2,4-dichlorophenolate with a purity of up to 99% can be increased to 94-95%.
If necessary, in order to produce 2,4-dichlorophenol, the residue of the alkali-metal 2,4-dichlorophenolate is exempted from the solvent, treated with a mineral acid and 2,4-dichlorophenol is recovered with a purity of above 99% in a yield of not less than 95-99%.
Therefore, the process according to the present invention enables preparation, subject to the consumer's requirements, both dehydrated alaklimetal 2,4-dichlorophenolate and pure 2,4-dichlorophenol.
For a better understanding of the present invention, some specific examples illustrating the process of the invention are given hereinbelow.
Example 1
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 82.0 g of commercial dichlorophenol (73.12 g of 2,4-dichlorophenol, 3.71 g of 2,6-dichlo rnphenol, 5.00 g of 2,4,6-trichlorophenol, 0.03 g of 2-chlorophenol, 0.14 g of 4-chlorophenol) are treated with 93.12 g of a 30% aqueous solution of potassium hydroxide in the presence of 164 g of toluene. The mass ratio of commercial dichlorophenol to toluene is 1:2. The resulting mixture containing potassium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture of toluene and water.On completion of the drying process which is controlled by elevation of the temperature in the flask above the boiling temperature of the azeotrope, the mixture of potassium chlorophenolates and toluene is cooled to the temperature of 30"C and maintained for 2 hours. The resulting potassium 2,4-dichlorophenolate precipitate is separated from the mixture by filtration. Toluene is removed from the residue by any conventional method. In this manner 78.56 g of purified potassium 2,4-dichlorophenolate are obtained. The product yield is 85.80% at the purity of 98.54% by mass.
In this Example and in the Examples given hereinbelow the term "commercial dichlorophenol" means a crude mixture of chlorophenols.
Example 2
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 95.0 g of commercial dichlorophenol (84.71 g of 2,4-dichlorophenol, 4.29 g of 2,6-dichlorophenol, 5.8 g of 2, 4,6-trichlorophenol, 0.04 g of 2-chlorophenol, 0.16 g of 4-chlorophenol) are treated with 107.90 g of a 30% aqueous solution of potassium hydroxide in the presence of 190 g of benzene. The mass ratio of commercial dichlorophenol to benzene is 1:2. The resulting mixture containing potassium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture benzene-water.
On completion of the drying process which is controlled by the elevation of temperature in the flask above the boiling temperature of the azeotropic mixture, the mixture of potassium chlorophenolates and benzene is cooled to the temperature of 30"C and kept for two hours. The resulting potassium 2,4-dichlorophenolate precipitate is separated from the mixture by filtration. Benzene is removed from the residue by any conventional method to give 92.70 g of purified potassium, 2,4- dichlorophenolate. The yield thereof is 87.01% at the purity of 98.09% by mass.
Example 3
In a three-neck flask provided with a stirrer, a thermometer, a Dean-Stark trap with a reflux condenser 77.13 g of commercial dichlorophenol (68.78 g of 2,4-dichlorophenol, 3.49 g of 2,6-dichlorophenol, 4.70 g of 2,4,6-trichlorophenol, 0.03 g of 2-chlorophenol, 0.13 g of 4-chlorophenol) are treated with 87.60 g of a 30% aqueous solution of potassium hydroxide in the presence of 77.3 g of toluene. The mass ratio of commercial dichlorophenol to toluene is equal to 1:1. The resulting mixture containing potassium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluenewater.On completion of the drying process which is controlled by elevation of temperature in the flask above the boiling temperature of the azeotrope the mixture of potassium chlorophenolates and toluene is cooled to the temperature of 30"C and maintained for two hours. The resulting precipitate of potassium 2,4-dichlorophenolate is separated from the mixture by filtration. Tolene is removed from the residue by any conventional method to give 90.95 g of purified 2,4-potassium dichlorophenolate. The product yield is 96.90% at the purity of 90.41% by mass.
Example 4
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 103.1 g of commercial dichlorophenol (91.93 g of 2,4-dichlorophenol, 4.66 g of 2,6-dichlorophenol, 6.29 g of 2,4,6-trichlorophenol, 0.04 g of 2-chlorophenol and 0.17 g of 4-chlorophenol) are treated with 117 g of a 30% aqueous solution of potassium hydroxide in the presence of 309.3 g of toluene. The mass ratio of commercial dichlorophenol to toluene is 1:3. The resulting mixture containing potassium chlorophenolates is subjected to an azetropic drying at the boiling temperature of the azeotrope toluene-water.On completion of the drying process which is controlled by temperature raising in the flask above the boiling temperature of the azeotrope the mixture of potassium chlorophenolates and toluene is cooled to the temperature of 30"C and kept at this temperature for 2 hours. The resulting precipitate of potassium 2, -dichlorophenolate is separated from the mixture by filtration. Toluene is removed from the residue by any conventional method to give 93.23 g of pure potassium 2,4-dichlorophenolate. The product yield is 81.4% at the purity of 99.03% by mass.
Example 5
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 75.03 g of commercial dichlorophenol (66.90 g of 2,4-dichlorophenol, 3.39 g of 2,6-dichlorophenol, 4.59 g of 2,4,6-trichlorophenol, 0.03 g of 2-chlorophenol and 0.12 g of 4-chlorophenol) are treated with 85.2 g of a 30% aqueous solution of potassium hydroxide in the presence of 150.1 g of p-xylene. The mass ratio of commercial dichlorophenol and p-xylene is equal to 1:2. The resulting mixture containing potassium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotrope p-xylene-water.On completion of the drying process which is controlled by temperature raising in the flask above the boiling temperature of the azeotrope, the mixture of potassium chlorophenolates and p-xylene is removed from the precipitate by any conventional method to give 65.3 g of potassium 2,4-dichlorophenolate. The product yield is equal to 73.8% at the purity of 93.% by mass.
Example 6
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 69.17 g of commercial dichlorophenol (2,4-dichlorophenol - 61.68 g, 3.13 g of 2,6-dichlorophenol, 4.22 g of 2,4,6-trichlorophenol, 0.03 g of 2-chlorophenol, 0.11 g of 4-chlorophenol) are treated with 235.7 g of a 10% aqueous solution of potassium hydroxide in the presence of 138.3 g of toluene. The mass ratio of commercial dichlorophenol and toluene is 1:2. The resulting mixture containing potassium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-water.
On completion of the drying process which is controlled by temperature raising in the flask above the boiling temperature of the azeotrope, the mixture of potassium chlorophenolates and toluene is cooled to the temperature of 40"C and kept at this temperature for 0.5 hour. The resulting precipitate of 2,4-potassium dichlorophenolate is separated from the mixture by filtration. Toluene is removed from the precipitate by any conventional method to give 65.55 g of purified potassium 2,4-dichlorophenolate. The product yield is 84.5% at the purity of 98.1% by mass.
Example 7
In a three-neck flask provided with a stirrer, a thermometer, a Dean-Stark trap with a reflux condenser 50.82 g of commercial dichlorophenol (45.31 g of 2,4-dichlorophenol, 2.30 g of 2,6-dichlorophenol, 3.10 g of 2,4,6-trichlorophenol, 0.02 g of 2-chlorophenol, 0.09 g of 4-chlorophenol) are treated with 86.6 g of a 20% aqueous solution of potassium hydroxide in the presence of 101.60 g of toluene. The mass ratio of commercial dichlorophenol and toluene. The mass ratio of commercial dichlorophenol and toluene is 1:2. The resulting mixture containing potassium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluenewater.On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope, the mixture of potassium chlorophenolates and toluene is cooled to the temperature of 20"C and kept for 2 hours. The resulting potassium 2,4-dichlorophenolate precipitate is separated from the mixture by filtration. Toluene is removed from the precipitate by any conventional method to give 49.02 g of purified potassium 2,4-dichlorophenolate. The product yield is 86.2% at the purity of 98.3% by mass.
Example 8
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 67.09 g of commercial dichlorophenol (59.83 g of 2,4-dichlorophenol, 3.03 g of 2,6-dichlorophenol, 4.09 g of 2,4,6-trichiorophenol, 0.03 g of 2-chlorophenol and 0.11 g of 4-chlorophenol) are treated with 50.8 g of a 45% aqueous solution of potassium hydroxide in the presence of 147.6 g of toluene. The mass ratio of commercial dichlorophenol to toluene is 1:2.2. The resulting mixture containing potassium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-water.
On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope, the mixture of potassium chlorophenolates and toluene is cooled to the temperature of 30"C and maintained for one hour. The resulting potassium 2,4-dichlorophenolate precipitate is separated from the mixture by filtration. Toluene is removed from the precipitate by any conventional method to give 64.27 g of purified potassium 2,4-dichlorophenolate. The product yield is 85.5% at the purity of 98.2% by mass.
Example 9
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 80.15 g of commercial (crudd) dichlorophenol (71.47 g of 2,4-chlorophenol, 3.62 g of 2,6dichlorophenol, 4.89 g of 2,4-dichlorophenol, 0.03 g of 2-chlorophenol and 1 0.14 g of 4-chlorophenol) are treated with 68.3 g of a 40% aqueous solution of potassium hydroxide in the presence of 184.3 g of toluene. The mass ratio of commercial dichlorophenol and toluene is 1:2.3. The resulting mixture containing potassium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-water.
On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope, the mixture of potassium chlorophenolates and toluene is cooled to the temperature of 10 C and kept for 2 hours. The resulting precipitate of potassium 2,4dichlorophenolate is separated from the mixture by filtration. Toluene is removed from the precipitate by any conventional method to give 81.48 g of purified potassium 2,4-dichlorophenolate. The product yield is 87.6% at the purity of 94.80% by mass.
Example 10
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser, 57.3 g of commercial dichlorophenol (51.09 g of 2,4-dichlorophenol, 2.59 g of 2,6-dichlorophenol, 3.50 g of 2,4,6-trichlorophenol, 0.02 g of 2-chlorophenol and 0.10 g of 4-chlorophenol) are treated with 65.1 g of a 30% aqueous solution of potassium hydroxide in the presence of 137.5 g of toluene. The mass ratio of commercial dichlorophenol and toluene is equal to 1:2.4. The resulting mixture containing potassium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotrope toluene-water. On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope, the mixture of potassium chlorophenolates and toluene is cooled to the temperature of 40 C and kept for 2 hours. The resulting precipitate of potassium 2,4dichlorophenolate is separated from the mixture by filtration. Toluene is removed from the precipitate by any conventional method to give 54.03 g of purified potassium 2,4-dichlorophenolate.The product yield is 85.2% at the purity of 99.39% by mass.
Example ii In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 79.43 g of commercial dichlorophenol (56.15 g of 2,4-dichlorophenol, 15.65 g of 2,6-dichlorophenol, 6.51 g of 1,4,6-trichlorophenol, 0.63 g of 2-chlorophenol and 0.49 g of 4-chlorophenol) are treated with 90.17 g of a 30% aqueous solution of potassium hydroxide in the presence of 182.7 g of toluene. The mass ration of commercial dichlorophenol to toluene is equal to 1;2.3. The resulting mixture containing potassium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluenewater.On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope, the mixture of potassium chlorophenolates and toluene is cooled to the temperature of 30"C and kept for 2 hours. The resulting precipitate of potassium 2,4-dichlorophenolate is separated from the mixture by filtration. Toluene is removed from the residue by any conventional method to give 59.02 g of purified potassium dichlorophenolate. The product yield is 80.6% at the purity of 94.6% by mass.
Example 12
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 61.42 g of commercial dichlorophenol (55.03 g of 2,4-dichlorophenol, 4.60 g of 2,6-dichlorophenol, 1.35 g of 2,4,6-trichlorophenol, 0.22 g of 2-chlorophenol, 0.22 g of 4-chlorophenol) are treated with 150.5 g of 10% aqueous solution of sodium hydroxide in the presence of 184.3 g of toluene and 4.91 g of n-butanol. The mass ratio of commercial dichlorophenol, toluene and n-butanol is equal to 1:3:0.08. The resulting mixture containing sodium chlorophenoaltes is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-n-butanol-water.On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope, the mixture of sodium chlorophenolates, toluene and nbutanol is cooled to the temperature of 30"C and maintained for 1 hour. The resulting precipitate of sodium 2,4-dichlorophenolate is separated from the mixture by filtration. Toluene and n-butanol are removed from the precipitate by any conventional method to give 57.49 g of purified sodium 2,4-dichlorophenolate. The product yield is 90.3% at the purity of 98.1% by mass.
Example 13
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 63.83 g of commercial dichlorophenol (57.19 g of 2,4-dichlorophenol, 4.78 g of 2,6-dichlorophenol, 1.41 g of 2,4,6- trichlorophenol, 0.22 g of 2-chlorophenol and 0.23 g of 4-chlorophenol) are treated with 52.1 g of a 30% aqueous solution of sodium hydroxide in the presence of 191.5 g of toluene and 9.6 g of ethanol. The mass ratio of commercial dichlorophenol, toluene and ethanol is equal to 1:3:0.15. The resulting mixture containing sodium phenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-ethanol-water.On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope the mixture of sodium chlorophenolates, toluene and ethanol is cooled to the temperature of 20"C and kept for 0.5 hour. The resulting precipitate of sodium 2,4-dichlorophenolate is separated from the mixture by filtration. Toluene and ethanol are removed from the precipitate by any conventional method to give 56.11 g of purified sodium 2,4-dichlorophenolate. The product yield is 81.6% at the purity of 94.4% by mass.
Example 14
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 69.78 g of commercial dichlorophenol (62.52 g of 2,4-dichlorophenol, 5.23 g of 2,6-dichlorophenol, 1.54 g of 2,4,6-trichlorophenol, 0.24 g of 2-chlorophenol and 0.25 g of 4-chlorophenol) are treated with 85.5 g of a 20% aqueous solution of sodium hydroxide in the presence of 209.3 g of toluene and 5.6 g of n-butanol. The mass ratio of commercial dichlorophenol, toluene and n-butanol is equal to 1:3:0.08. The resulting mixture containing sodium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-n-butanol-water.On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope the mixture of sodium chlorophenolates, toluene and nbutanol is cooled to the temperature of 30"C and kept for 0.08 hour. The resulting precipitate of sodium 2,4-dichlorophenolate is separated from the mixture by filtration. Toluene and n-butanol are removed from the precipitate by any conventional method to give 63.42 g of purified sodium 2,4-dichlorophenolate. The product yield is 87.5% at the purity of 97.9% by mass.
Example 15
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 70.47 g of commercial dichlorophenol (63.14 g of 2,4-dichlorophenol, 5.28 g of 2,6-dichlorophenol, 1.55 g of 2,4,6-trichlorophenol, 0.25 g of 2-chlorophenol, 0.25 g of 4-chlorophenol) are treated with 34.54 g of a 50% aqueous solution of sodium hydroxide in the presence of 70.47 g of toluene and 3.52 g of n-butanol. The mass ratio of commercial dichlorophenol, toluene and n-butanol is 1:1:0.5. The resulting mixture containing sodium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-n-butanol-water.On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope the mixture of sodium chlorophenolates, toluene nd n-butanol is cooled to the temperature of 40"C and kept for 0.25 hour.
The resulting precipitate of sodium 2,4-dichlorophenolate is separated from the mixture by filtration. Toluene and n-butanol are removed from the precipitate by any conventional method to give 64.41 g of purified sodium 2,4-dichlorophenolate.
The product yield is 86.1% at the purity of 95.8% by mass.
Example 16
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap 71.85 g of commercial dichlorophenol (64.38 g of 2,4-dichlorophenol, 5.38 g of 2,6-dichlorophenol, 1.58 g of 2,4,6-trichlorophenol, 0.25 g of 2-chlorophenol and 0.26 g of 4-chlorophenol) are treated with 44 g of a 40% aqueous solution of sodium hydroxide in the presence of 215.6 g of toluene and 7.2 g of n-butanol. The mass ratio of commercial dichlorophenol, toluene and n-butanol is equal to 1:3:0.1.
The resulting mixture containing sodium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-n-butanol-water. On completion of the drying process which is controlled by temperature elevationin the flask above the boiling temperature of the azeotrope the mixture of sodium chlorophenolates, toluene and n-butanol is cooled to the temperature of 20C and kept for 0.5 hour. The resulting precipitate of sodium 2,4-dichlorophenolate is separated from the mixture by filtration. Toluene and n-butanol are removed from the precipitate by any conventional method to give 65.78 g of purified sodium 2,4-dichlorophenolate. The product yield is equal to 89.3% at the purity of 99.2% by mass.
Example 17
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 59.72 g of commercial dichlorophenol (53.52 g of 2,4-dichlorophenol, 4.47 g of 2,6-dichlorophenol, 1.31 g of 2,4,6-trichlorophenol, 0.21 g of 2-chlorophenol, 0.21 g of 4-chlorophenol) are treated with 36.6 g of a 40% aqueous solution of sodium hydroxide in the presence of 119.4 g of toluene and 5.97 g of n-butanol. The mass ratio of commercial dichlorophenol, toluene and n-butanol is equal to 1:2:0.1. The resulting mixture containing sodium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-n-butanol-water.On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope the mixture of sodium chlorophenolates, toluene and nbutanol is cooled to the temperature of 10 and kept for one hour. The resulting precipitate of sodium 2,4-dichlorophenolate is separated from the mixture by filtration. Toluene and n-butanol are removed from the precipitate by any conventional method to give 52.71 g of purified sodium 2,4-dichlorophenolate. The product yield is 85.3% at the purity of 98.3% by mass.
Example 18
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 64.44 g of commercial dichlorophenol (57.73 g of 2,4-dichlorophenol, 4.83 g of 2,6-dichlorophenol, 1.42 g of 2,4,6-trichlorophenol, 0.23 g of 2-chlorophenol and 0.23 g of 4-chlorophenol) are treated with 45.1 g of a 35% aqueous solution of sodium hydroxide in the presence of 193.3 g of toluene and 5.2 g of n-butanol. The mass ratio of commercial dichlorophenol, toluene and n-butanol is equal to 1:3:0.08. The resulting mixture containing sodium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-n-butanol-water.On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope the mixture of sodium chlorophenolates, toluene and nbutanol is cooled to the temperature of 50"C and kept for 0.5 hour. The resulting precipitate of sodium 2,4-dichlorophenolate is separated from the mixture by filtration. Toluene and-n-butanol are removed by any conventional method to give 59.82 g of purified sodium 2,4-dichlorophenolate. The product yield is 89.2% at the purity of 197.7% by mass.
Example 19
in a three-neck flask provided with a stirrer, thermometer and a Dean-Stark trap with a reflux condenser 74.51 g of commercial dichlorophenol (66.76 g of 2,4-dichlorophenol, 5.58 g of 2,6-dichlorophenol, 1.64 g of 2,4,6-trichlorophenol, 0.26 g of 2-chlorophenol, 0.27 g of 4-chlorophenol) are treated with 65.2 g ofa 28% aqueous solution of sodium hydroxide in the presence of 223.5 g of toluene and 14.9 g of n-butanol. The mass ratio of commercial dichlorophenol, toluene and n-butanol is equal to 1:3:0.2. The resulting mixture containing sodium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-n-butanol-water.On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope the mixture of sodium chlorophenolates, toluene and nbutanol is cooled to the temperature of 20"C and maintained for 0.16 hour. The formed precipitate of sodium 2,4-dichlorophenolate is separated from the mixture by filtration. Toluene and n-butanol are removed from the precipitate by any conventional method to give 61.33 g of purified sodium 2,4-dichlorophenolate. The product yield is 79.0% at the purity of 97.6% by mass.
Example 20
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 84.22 g of commercial dichlorophenol (75.46 g of 2,4-dichlorophenol, 6.31 g of 2,6-dichlorophenol, 1.95 g of 2,4,6-trichlorophenol, 0.30 g of 2-chlorophenol and 0.30 g of 4-chlorophenol) are treated with 68.8 g of a 30% aqueous solution of sodium hydroxide in the presence of 252.7 g of ktoluene and 12.6 g of isopropanol. The mass ratio of commercial dichlorophenol, toluene and isopropanol is 1:3:0.15. The resulting mixture containing sodium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-isopropanol-water.On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope, the mixture of sodium chlorophenolates, toluene and isopropanol is cooled to the temperature of 10"C and kept for 0.16 hour. The resulting sodium 2,4-dichlorophenolate is separated from the mixture by filtration. Toluene and isopropanol are removed from the precipitate by any conventional method to give 70.10 g of purified sodium 2,4-dichlorophenolate.
The product yield is 78.0% at the purity of 95.3% by mass.
Example 21
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 64.74 g of commercial dichlorophenol (58.01 g of 2,4-dichlorophenol, 4.85 g of 2,6-dichlorophenol, 1.42 g of 2,4,6-trichlorophenol, 0.23 g of 2-chlorophenol and 0.23 g of 4-chlorophenol) are treated with 52.9 g of a 30% aqueous solution of sodium hydroxide in the presence of 194.2 g of toluene and 9.7 g of n-butanol. The mass ratio of commercial dichlorophenol, toluene and n-butanol is equal to 1:3:0.15. The resulting mixture containing sodium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-n-butanol-water.On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of th azeotrope, the mixture of sodium chlorophenolates, toluene and nbutanol is cooled to the temperature of 10"C, and kept for 0.16 hour. The resulting precipitate of sodium 2,4-dichlorophenolate is separated from the mixture by filtration. Toluene and n-butanol are removed from the precipitate by any conventional method to give 56.59 g of purified sodium 2,4-dichlorophenolate. The product yield is 85.0% at the purity of 98.9% by mass.
Example 22
in a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 37.40 g of commercial dichlorophenol (33.51 g of 2,4-dichlorophenol, 2.80 g of 2,6-dichlorophenol, 0.82 g of 2,4,6-trichlorophenol, 0.19 g of 2-chlorophenol and 0.08 g of 4-chlorophenol) are treated with 29.6 g of a 31% aqueous solution of sodium hydroxide in the presence of 112.2 g of toluene and 3.7 g of n-butanol. The mass ratio of commercial dichlorophenol, toluene and butanol is equal to 1:3:0.1. The resulting mixture containing sodium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-n-butanol-water.On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope, the mixture of sodium chlorophenolates, toluene and nbutanol is cooled to the temperature of 20"C and kept for 0.5 hour. The resulting sodium 2,4-dichlorophenolate precipitate is separated from the mixture by filtration. Toluene and n-butanol are removed from the precipitate by conventional methods to give 29.6 g of purified 2,4-dichlorophenol. The product yield is 88.01% at the purity of 99.6% by mass.
Example 23
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 43.70 g of commercial dichlorophenol (38.97 g of 2,4-dichlorophenol, 1.98 g of 2,6-dichlorophenol, 2.66 g of 2,4,6-trichlorophenol, 0.02 g of 2-chlorophenol and 0.07 g of 4-chlorophenol) are treated with 44.3 g of a 24% aqueous solution of sodium hydroxide in the presence of 131.1 g of toluene and 4.4 g of n-butanol. The mass ratio of commercial dichlorophenol, toluene and n-butanol is 1:3:0.1. The resulting mixture containing sodium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-n-butanol-water.On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope, the mixture of sodium chlorophenolates, toluene and n-butanol is cooled to the temperature of 30"C and kept for 0.33 hour.
The resulting precipitate of sodium 2,4-dichlorophenolate is separated from the mixture by filtration. Toluene and n-butanol are recovered from the precipitate by conventional methods to give 35.62 g of purified 2,4-dichlorophenol. The product yield is 90.67% at the purity of 99.2% by mass.
Example 24
In an apparatus provided with an agitator, means for distilling-off an azeotropic mixture and means for recycling the organic layer into the system 93 kg of commercial dichlorophenol (84.8 kg of 2,4dichlorophenol, 3.8 kg of 2,6-dichlorophenol, 3.9 kg of 2,4,6-trichlorophenol, 0.4 kg of 2-chlorophenol, 0.1 kg of 4-chlorophenol) are treated with 75.6 kg of a 30% aqueous solution of sodium hydroxide in the presence of 279 kg of toluene and 9.3 kg of nbutanol. The mass ratio of commercial dichlorphenol, toluene and n-butanol is equal to 1:3:0.1.
The resulting mixture contsining sodium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-n-butanol-water. On completion of the drying process which is controlled by temperature elevation in the apparatus above the boiling temperature of the azeotrope, the mixture of sodium chlorophenolates, toluene and n-butanol is cooled to the temperature of 30"C and kept for 0.5 hour.
The precipitate is filtered-off, toluene and n-butanol are removed therefrom. The residue is treated with an aqueous solution of hydrochloric acid to isolate 76.7 kg of purified 2,4-dichlorophenol. The product yield is 89.6% at the purity of 99.03% by mass.
Example 25
In a three-neck flask provided with a stirrer, a thermometer and a Dean-Stark trap with a reflux condenser 80.01 g of commercial dichlorophenol (71.34 g of 2,4-dichlorophenol, 3.62 g of 2,6-dichlorophenol, 4.88 g of 2,4,6-trichlorophenol, 0.03 g of 2-chlorophenol, 0.14 g of 4-chlorophenol) are treated with 90.9 g of a 30% aqueous solution of potassium hydroxide in the presence of 196.8 g of toluene. The mass ratio of commercial dichlorophenol to toluene is 1:2.46. The resulting mixture containing potassium chlorophenolates is subjected to an azeotropic drying at the boiling temperature of the azeotropic mixture toluene-water.
On completion of the drying process which is controlled by temperature elevation in the flask above the boiling temperature of the azeotrope, the mixture of potassium chlorophenolates and toluene is cooled to the temperature of 40"C and kept for one hour. The resulting precipitate of potassium 2,4dichlorophenolate is separated from the mixture by filtration. Toluene is removed from the precipitate by any conventional method to give 75.60 g of purified potassium 2,4-dichlorophenolate. The product yield is 85.0% at the purity of 99.03% by mass.
Toluene is distilled-off to the content thereof in the remaining filtrate equal to 46.3 g. The mixture of potassium chlorophenolates and toluene is cooled to the temperature of 40"C and maintaining at this temperature for one hour. The precipitate of potassium 2,4-dichlorophenolate is separated by filtration. Toluene is removed from the residue by any conventional method to give additionally 9.62 g of purified potassium 2,4-dichlorophenolate with the purity of 94.1% by mass. This residue is delivered to the stage of azeotropic drying or mixed with purified potassium 2,4-dichlorophenolate resulting from the previous stage. The total amount of purified potassium 2,4-dichlorophenolate is 85.22 g. The total yield of potassium 2,4-dichlorophenolate is equal to 95.35% at the purity of 98.47% by mass.
Claims (6)
1. A process for isolating an alkali-metal 2,4dichlorophenolate and 2,4-dichiorophenol from a mixture of chlorophenols comprising reacting a mixture of chlorophenols with an aqueous solution of an alkali in the presence of an aromatic hydrocarbon with a boiling point within the range of from 80 to 1500C or a mixture thereof with an aliphatic alcohol at a mass ratio between the mixture of chlorophenols and the aromatic hydrocarbon of 1:1-3 respectively or of the mixture of chlorophenols, the aromatic hydrocarbon and the aliphatic alcohol of 1:1-3:0.05-0.2 respectively to form a mixture containing the alkali metal chlorophenoiates, azeotropic drying of the mixture and cooling thereof followed by recovering the alkali-metal 2,4 dichlorophenolate as a precipitate which is treated, when necessary, with a mineral acid to give 2,4dichlorophenol.
2. A process according to Claim 1, wherein cooling is effected to a temperature within the range of from 10 to 500C and said mixture is maintained at this temperature for 0.08-2 hours.
3. A process according to Claims 1 and 2, wherein a 10-50% aqueous solution of an alkali is used.
4. A process according to Claims 1 to 3, wherein as the aromatic hydrocarbon benzene, toluene and isomeric xylenes are used.
5. A process according to Claims 1 to 4, wherein as the aliphatic alcohol C2-C4-alcohols are used.
6. A process for recovering an alkali metal 2,4dichlorophenolate and 2,4-dichlorophenol from a mixture of chlorophenols substantially as described in the Specification and Examples 1 through 25 hereinbefore.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT132885A AT381928B (en) | 1985-05-14 | 1985-05-03 | METHOD FOR SEPARATING PURE 2,4-DICHLOR-PHENOLATE FROM AN ALKALINE METAL OR. FROM PURE 2,4-DICHLORPHENOL FROM A TECHNICAL 2,4-DICHLORPHENOL |
| GB8512199A GB2175299B (en) | 1985-05-14 | 1985-05-14 | Process for isolating alkali metal 2,4-dichlorophenolate and 2,4-dichlorophenol from a mixture of chlorophenols |
| NL8501414A NL8501414A (en) | 1985-05-14 | 1985-05-15 | PROCESS FOR INSULATING ALKALIMETAL-2,4-DICHLOROPHENOLATE AND 2,4-DICHLOROPHENOL FROM A MIXTURE OF CHLOROPHENOLS. |
| DE19853519039 DE3519039A1 (en) | 1985-05-14 | 1985-05-28 | METHOD FOR SEPARATING THE 2,4-DICHLORPHENOLATE FROM AN ALKALINE METAL AND 2,4-DICHLORPHENOL FROM A MIXTURE OF CHLORPHENOLS |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8512199A GB2175299B (en) | 1985-05-14 | 1985-05-14 | Process for isolating alkali metal 2,4-dichlorophenolate and 2,4-dichlorophenol from a mixture of chlorophenols |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8512199D0 GB8512199D0 (en) | 1985-06-19 |
| GB2175299A true GB2175299A (en) | 1986-11-26 |
| GB2175299B GB2175299B (en) | 1989-06-28 |
Family
ID=10579120
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8512199A Expired GB2175299B (en) | 1985-05-14 | 1985-05-14 | Process for isolating alkali metal 2,4-dichlorophenolate and 2,4-dichlorophenol from a mixture of chlorophenols |
Country Status (4)
| Country | Link |
|---|---|
| AT (1) | AT381928B (en) |
| DE (1) | DE3519039A1 (en) |
| GB (1) | GB2175299B (en) |
| NL (1) | NL8501414A (en) |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU406824A1 (en) * | 1971-06-01 | 1973-11-21 | М. С. Бакиров, А. Д. Игошев, В. Н. Лукашенок, А. С. Соболев, С. В. Зубарев , И. Пенышкина Уфимский химический завод | The method of separation of chlorinated phenols |
-
1985
- 1985-05-03 AT AT132885A patent/AT381928B/en not_active IP Right Cessation
- 1985-05-14 GB GB8512199A patent/GB2175299B/en not_active Expired
- 1985-05-15 NL NL8501414A patent/NL8501414A/en not_active Application Discontinuation
- 1985-05-28 DE DE19853519039 patent/DE3519039A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| DE3519039C2 (en) | 1989-02-02 |
| GB8512199D0 (en) | 1985-06-19 |
| GB2175299B (en) | 1989-06-28 |
| NL8501414A (en) | 1986-12-01 |
| DE3519039A1 (en) | 1986-12-04 |
| ATA132885A (en) | 1986-05-15 |
| AT381928B (en) | 1986-12-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4209646A (en) | Process for crystallizing an adduct of 2,2-di(4-hydroxyphenyl) propane and phenol | |
| US4533764A (en) | Purification of bisphenols by removing residual solvent | |
| US4162270A (en) | Process for producing 4,4'-dihydroxydiphenylsulfone of high purity | |
| US5136052A (en) | Process for the manufacture of n-phenylmaleimide | |
| US3290391A (en) | Production and purification of a diphenylolpropane | |
| JPS59231033A (en) | Purification of bisphenol a | |
| US4467117A (en) | Process for the production and purification of 2,4,4'-trichloro-2'-hydroxydiphenylether | |
| US3207795A (en) | Production and purification of diphenylolalkanes | |
| US4780567A (en) | Process for producing aromatic hydroxycarboxylic acids | |
| US4012451A (en) | Process for the separation of 4,4'-dichlorodiphenylsulfone | |
| JPH0446253B2 (en) | ||
| US3359281A (en) | Separation and isolation of 2, 2, (2, 4'-dihydroxydiphenyl) propane and 2, 2, 4-trimethyl 4(4'-hydroxyphenyl) chroman from mixtures containing the same | |
| GB2175299A (en) | Isolation of alkali metal 2,4-dichlorophenolate and 2,4-dichlorophenol from a mixture of chlorophenols | |
| US4352941A (en) | Process for purification of phenylhydrazine | |
| CA1268779A (en) | Isolation process | |
| EP0093511A1 (en) | Method for producing and optically active 2,2-dimethylcyclopropanecarboxylic acid | |
| US4686301A (en) | Process for the preparation of 2,4-dinitrophenol alkoxyalkyl ethers | |
| JP3157724B2 (en) | Indole purification method | |
| US5274131A (en) | 2-chloropropionaldehyde trimer and production process thereof | |
| US5183937A (en) | Acetic acid recovery | |
| US3821294A (en) | Process for producing very pure tetra chlorobisphenol a | |
| US4778568A (en) | Process for separating isomer mixtures of 1,3- and 1,4- bis-(2-hydroxyhexafluoro-prop-2-yl)-benzene | |
| JP2798293B2 (en) | How to recover phenols | |
| Perkin et al. | LXXXI.—Experiments on the synthesis of camphoric acid. Part V. A synthesis of camphoric acid | |
| JPH08325183A (en) | Method for producing bisphenol A |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |