CN109232400B - Method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine - Google Patents
Method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine Download PDFInfo
- Publication number
- CN109232400B CN109232400B CN201811400657.1A CN201811400657A CN109232400B CN 109232400 B CN109232400 B CN 109232400B CN 201811400657 A CN201811400657 A CN 201811400657A CN 109232400 B CN109232400 B CN 109232400B
- Authority
- CN
- China
- Prior art keywords
- dichloro
- hydrogen fluoride
- reaction
- trifluoromethylpyridine
- continuously synthesizing
- 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.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/60—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D213/61—Halogen atoms or nitro radicals
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Pyridine Compounds (AREA)
Abstract
The invention discloses a method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine, which comprises the steps of preheating 2, 3-dichloro-5-trichloromethylpyridine, pressurizing hydrogen fluoride, respectively pumping two raw materials into a tubular reactor by a pump and a mass flow meter, controlling the reaction temperature to be 150-, the waste gas can be recycled after separation and post-treatment, so that the emission of waste gas is greatly reduced.
Description
Technical Field
The invention belongs to the field of fine chemical synthesis, and particularly relates to a method for synthesizing 2, 3-dichloro-5-trifluoromethylpyridine by a continuous method.
Background
2, 3-dichloro-5-trifluoromethyl pyridine is the important organic intermediate of synthetic pesticide and medicine, the production method reported at present mostly regards catalyst preparation as the main, apply to the synthetic field of pesticide, medicine, fine chemical industry extensively, there are extensive market prospects, patent CN 104557683 adds the catalyst, the kettle type reaction, the product yield is less than 70%, the invention removes the use of catalyst, adopt the tubular reaction, under certain pressure and temperature, two kinds of supplies are fed continuously; the yield is improved, and the waste gas generated in the reaction can be cooled and recycled; is green and environment-friendly.
Disclosure of Invention
The invention provides a method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine, which overcomes the defects of kettle type reaction in the traditional process, does not adopt a catalyst, reduces the cost for producing the catalyst, does not need to recover the catalyst for regeneration after the reaction, adopts tubular reaction, continuously reacts two materials at a certain temperature and pressure, has high product yield, and can reduce pollution and improve the environment by recovering waste gas generated by the reaction through low temperature cooling.
The invention aims to provide a method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine, which does not use a catalyst and comprises the following steps:
(1) preheating the raw material 2, 3-dichloro-5-trichloromethylpyridine;
(2) pressurizing the hydrogen fluoride to 5-8 mpa;
(3) respectively pumping the two materials in the steps (1) and (2) into a tubular reactor by using a metering pump and a mass flow meter;
(4) the reaction temperature is controlled to be 150 ℃ and 250 ℃, and the reaction pressure is 3-6 mpa; the retention time is 3-6 h;
(5) collecting the reaction liquid to a collecting and receiving tank, controlling the temperature of the receiving tank to be 20-90 ℃,
collecting reaction liquid and rectifying to obtain a pure product; and collecting the waste gas to a tail gas absorption tank for cooling and separation.
In the technical scheme, the raw material 2, 3-dichloro-5-trichloromethylpyridine is preheated and pressurized by hydrogen fluoride, wherein the preheating temperature is 100-150 ℃, and the preferable preheating temperature is 120-140 ℃; the hydrogen fluoride is pressurized with nitrogen at a pressure of 5 to 8mpa, preferably at a pressure of 6 to 8 mpa.
In the technical scheme, the hydrogen fluoride has high corrosivity, and the reaction tube made of a common material cannot ensure pressure, so that the reaction tube used by the invention is made of hastelloy, and is DN20 in specification and 5m long.
In the technical scheme, the flow rate of the preheated raw material 2, 3-dichloro-5-trichloromethylpyridine is 700g/h, preferably 650g/h, of 550.
In the above technical solution, a mass flow meter is adopted for feeding the hydrogen fluoride, the flow rate of the hydrogen fluoride is 160g/h, and the preferred feeding flow rate is 155 g/h.
In the technical scheme, the molar ratio of the two raw materials of 2, 3-dichloro-5-trichloromethyl pyridine to hydrogen fluoride is 1: 1-4, and the molar ratio of the two raw materials is preferably 1: 2.5-3.5.
In the above technical scheme, the reaction temperature in the synthesis process is 150-.
In the above-mentioned technical scheme, the reaction pressure is preferably 4-5 mpa.
In the technical scheme, the melting point of a reaction product is 8-9 ℃, so that a reaction liquid receiver needs to be preheated to prevent the product from being separated out; the preheating temperature of the reaction liquid receiving container is controlled to be 20-90 ℃, and the preheating temperature is preferably 40-60 ℃.
In the technical scheme, the reaction raw material hydrogen fluoride and the hydrogen chloride generated by the reaction escape from the preheated receiving tank, are collected in the gas storage tank, are cooled, are recycled, and are separated.
The invention designs a method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine, which does not use a catalyst, reduces the production cost, reduces the regeneration link of the catalyst and simplifies the process; the traditional kettle type reaction is overcome, a hastelloy reaction tube is adopted, two materials are continuously fed and reacted, and the retention time of the raw materials is controlled; the yield is improved; the yield is more than 80%, the product purity is more than 98%, and the method is simple to operate; the waste gas generated by the reaction can be recovered through low-temperature cooling.
Detailed Description
The invention is further illustrated by the following examples.
Example 1
Preheating raw material 2, 3-dichloro-5-trichloromethyl pyridine to 120 ℃, pressurizing hydrogen fluoride to 6mpa by using nitrogen, starting feeding, feeding the 2, 3-dichloro-5-trichloromethyl pyridine by using a metering pump, and controlling the flow rate: 550g/h, feeding hydrogen fluoride by using a mass flow meter; the flow rate is 135g/h, the molar ratio of the two materials is 1:3.2, the reaction temperature is controlled to be 170 ℃, the reaction pressure is controlled to be 4mpa, and the temperature of a reaction liquid receiving container is 40 ℃; collecting and rectifying reaction liquid; the yield of the product is 69 percent, and the purity is more than 98.2 percent.
Example 2
Preheating raw material 2, 3-dichloro-5-trichloromethyl pyridine to 140 ℃, pressurizing hydrogen fluoride to 7mpa by using nitrogen, starting feeding, feeding the 2, 3-dichloro-5-trichloromethyl pyridine by using a metering pump, and controlling the flow rate: 550g/h, feeding hydrogen fluoride by using a mass flow meter; the flow rate is 135g/h, the molar ratio of the two materials is 1:3.2, the reaction temperature is controlled to be 170 ℃, the reaction pressure is controlled to be 3.5mpa, and the temperature of a reaction liquid receiving container is 40 ℃; collecting and rectifying reaction liquid; the yield of the product is 66 percent, and the purity is 98.1 percent.
Example 3
Preheating raw material 2, 3-dichloro-5-trichloromethyl pyridine to 130 ℃, pressurizing hydrogen fluoride to 7mpa by using nitrogen, starting feeding, feeding the 2, 3-dichloro-5-trichloromethyl pyridine by using a metering pump, and controlling the flow rate: 600g/h, feeding hydrogen fluoride by using a mass flow meter; the flow rate is 135g/h, the molar ratio of the two materials is 1:3, the reaction temperature is controlled to be 170 ℃, the reaction pressure is controlled to be 4mpa, and the temperature of a reaction liquid receiving container is 40 ℃; collecting and rectifying reaction liquid; the product yield is 79 percent, and the purity is 98.2 percent.
Example 4
Preheating raw material 2, 3-dichloro-5-trichloromethyl pyridine to 130 ℃, pressurizing hydrogen fluoride to 6mpa by using nitrogen, starting feeding, feeding the 2, 3-dichloro-5-trichloromethyl pyridine by using a metering pump, and controlling the flow rate: 600g/h, feeding hydrogen fluoride by using a mass flow meter; the flow rate is 160g/h, the molar ratio of the two materials is 1:3.5, the reaction temperature is controlled to be 190 ℃, the reaction pressure is controlled to be 5mpa, and the temperature of a reaction liquid receiving container is 40 ℃; collecting and rectifying reaction liquid; the product yield is 79.5 percent, and the purity is 98.5 percent.
Example 5
Preheating raw material 2, 3-dichloro-5-trichloromethyl pyridine to 130 ℃, pressurizing hydrogen fluoride to 6mpa by using nitrogen, starting feeding, feeding the 2, 3-dichloro-5-trichloromethyl pyridine by using a metering pump, and controlling the flow rate: 530g/h, hydrogen fluoride is fed by a mass flow meter; the flow rate is 140g/h, the molar ratio of the two materials is 1:3.5, the reaction temperature is controlled to be 180 ℃, the reaction pressure is controlled to be 5mpa, and the temperature of a reaction liquid receiving container is 40 ℃; collecting and rectifying reaction liquid; the product yield is 79 percent, and the purity is 98.5 percent.
Example 6
Preheating raw material 2, 3-dichloro-5-trichloromethyl pyridine to 140 ℃, pressurizing hydrogen fluoride to 7mpa by using nitrogen, starting feeding, feeding the 2, 3-dichloro-5-trichloromethyl pyridine by using a metering pump, and controlling the flow rate: 550g/h, feeding hydrogen fluoride by using a mass flow meter; the flow rate is 135g/h, the molar ratio of the two materials is 1:3.2, the reaction temperature is controlled to be 170 ℃, the reaction pressure is controlled to be 4mpa, and the temperature of a reaction liquid receiving container is 40 ℃; collecting and rectifying reaction liquid; the product yield is 80%, and the purity is 98.0%.
Example 7
Preheating raw material 2, 3-dichloro-5-trichloromethyl pyridine to 140 ℃, pressurizing hydrogen fluoride to 6mpa by using nitrogen, starting feeding, feeding the 2, 3-dichloro-5-trichloromethyl pyridine by using a metering pump, and controlling the flow rate: 550g/h, feeding hydrogen fluoride by using a mass flow meter; the flow rate is 135g/h, the molar ratio of the two materials is 1:3.2, the reaction temperature is controlled to be 200 ℃, the reaction pressure is controlled to be 4mpa, and the temperature of a reaction liquid receiving container is 40 ℃; collecting and rectifying reaction liquid; the product yield is 80%, and the purity is 98.0%.
Claims (6)
1. A method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine is characterized by comprising the following steps without using a catalyst:
(1) preheating the raw material 2, 3-dichloro-5-trichloromethylpyridine;
(2) pressurizing the hydrogen fluoride to 5-8 mpa; the mol ratio of the 2, 3-dichloro-5-trichloromethylpyridine to the hydrogen fluoride is 1: 3-3.5;
(3) respectively pumping the two materials in the steps (1) and (2) into a tubular reactor by using a metering pump and a mass flow meter;
(4) controlling the reaction temperature to be 180 ℃ and 200 ℃, and controlling the reaction pressure to be 3-6 mpa;
(5) collecting the reaction liquid to a receiving tank, controlling the temperature of the receiving tank to be 20-90 ℃, and rectifying the reaction liquid after collection to obtain a pure product; collecting waste gas to a tail gas absorption tank for cooling and separation; and the gas discharged from the receiving tank is cooled to separate hydrogen fluoride and hydrogen chloride, and the hydrogen fluoride is recovered for recycling.
2. The method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine according to claim 1, wherein: in the step (1), the preheating temperature of the raw material is 100-150 ℃.
3. The method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine according to claim 1, wherein: in the step (2), the hydrogen fluoride is pressurized with nitrogen.
4. The method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine according to claim 1, wherein: in the step (3), the tubular reactor is DN20 and a Hastelloy tube with the length of 5 m.
5. The method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine according to claim 1, wherein: the flow rate of the raw material of the 2, 3-dichloro-5-trichloromethylpyridine is 400-700 g/h.
6. The method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine according to claim 1, wherein: the flow rate of the hydrogen fluoride is 110-160 g/h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811400657.1A CN109232400B (en) | 2018-11-22 | 2018-11-22 | Method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811400657.1A CN109232400B (en) | 2018-11-22 | 2018-11-22 | Method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109232400A CN109232400A (en) | 2019-01-18 |
| CN109232400B true CN109232400B (en) | 2020-10-27 |
Family
ID=65075799
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811400657.1A Active CN109232400B (en) | 2018-11-22 | 2018-11-22 | Method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109232400B (en) |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0001473B1 (en) * | 1977-08-12 | 1988-07-27 | Imperial Chemical Industries Plc | Herbicidal halogenomethyl--pyridyloxy-phenoxy-alkanecarboxylic acids and derivatives, and processes of controlling unwanted plants therewith |
| US4266064A (en) * | 1979-03-19 | 1981-05-05 | Ishihara Sangyo Kaisha Ltd. | Process for producing chloro β-trifluoromethylpyridines |
| IL70307A (en) * | 1982-11-26 | 1987-02-27 | Dow Chemical Co | Preparation of(trifluoromethyl)pyridines |
| CN1202082C (en) * | 2000-09-13 | 2005-05-18 | 中国科学院大连化学物理研究所 | Process for synthesizing 2-Cl-5-trifluoromethyl pyridine |
| CN103787961A (en) * | 2014-03-07 | 2014-05-14 | 江苏省激素研究所股份有限公司 | Efficient haloxyfop-methyl synthesizing method |
| CN106008330A (en) * | 2016-06-06 | 2016-10-12 | 山东福尔有限公司 | Preparation method for 2,3-dichloro-5-(trifluoromethyl)pyridine |
| CN106316933B (en) * | 2016-08-20 | 2018-06-19 | 大连九信精细化工有限公司 | A kind of continuous preparation method of the fluoro- 6- trifluoromethyl pyridines of 2- |
| CN106397309A (en) * | 2016-08-31 | 2017-02-15 | 南京红太阳生物化学有限责任公司 | Synthetic method of 2,3-dichloro-5-trifluoromethylpyridine |
-
2018
- 2018-11-22 CN CN201811400657.1A patent/CN109232400B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109232400A (en) | 2019-01-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102675035B (en) | Method for preparing vinyl chloride from acetylene and dichloroethane | |
| CN111574400B (en) | Separation method of ammoniated and dehydrated product of caprolactam and synthesis method of hexamethylene diamine | |
| CN101544535A (en) | Method for preparing synthetic 1,1,1,3,3-pentachloro propane | |
| CN109748804B (en) | Production method of isopropanolamine | |
| CN111574344A (en) | Preparation method for producing acetaldehyde by catalyzing acetylene with ZAPO molecular sieve | |
| CN102219680A (en) | Method for preparing oxalic ester by CO gas-phase process | |
| CN109232400B (en) | Method for continuously synthesizing 2, 3-dichloro-5-trifluoromethylpyridine | |
| CN102911008A (en) | Trichloro ethylene preparation method | |
| CN102408301B (en) | Method for preparing methyl chloride and ammonia by using ammonium chloride and methanol | |
| CN110407725B (en) | Preparation method of 2-mercaptoethanol | |
| CN109400506B (en) | Synthesis method of high-purity chlorosulfonyl isocyanate | |
| CN101462943A (en) | Method for preparing oxalate with co-production products oxalic acid and dihydric phosphate by continuous dehydrogenation of formate | |
| CN101306980B (en) | Method for preparing perchloro cyclopentadiene | |
| CN208883749U (en) | A kind of hydroxyacetonitrile serialization prepares the coiled reaction unit of glycine | |
| CN103145561B (en) | Continuous production method for perfluoro tripropylamine | |
| CN114230445B (en) | Preparation method and production system of ethylene glycol monovinyl ether | |
| CN111153779A (en) | Efficient synthesis method of m-fluoroanisole | |
| CN104529688B (en) | A kind of continuous method by ethane to ethylene | |
| CN103130608B (en) | Preparation method of trifluoroethylene | |
| CN215162273U (en) | 3-methylpyridine continuous production system | |
| CN219559579U (en) | Closed loop production system of trifluoroethanol | |
| CN114315642B (en) | Synthesis method of 6-aminocapronitrile | |
| CN113717025B (en) | Synthesis method of chloroterpentane | |
| CN111153787B (en) | Preparation method of 1-naphthylacetic acid | |
| CN109942366A (en) | A kind of devices and methods therefor reacting production chloromethanes with methanol using hydrogen chloride and ammonium chloride |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |