CN110577469A - Preparation method of 3-chloro-2, 4, 5-trifluorobenzoic acid - Google Patents
Preparation method of 3-chloro-2, 4, 5-trifluorobenzoic acid Download PDFInfo
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- CN110577469A CN110577469A CN201910940286.4A CN201910940286A CN110577469A CN 110577469 A CN110577469 A CN 110577469A CN 201910940286 A CN201910940286 A CN 201910940286A CN 110577469 A CN110577469 A CN 110577469A
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- C07C227/02—Formation of carboxyl groups in compounds containing amino groups, e.g. by oxidation of amino alcohols
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- C—CHEMISTRY; METALLURGY
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- C07C253/00—Preparation of carboxylic acid nitriles
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- C07C51/347—Preparation of carboxylic acids or their salts, halides or anhydrides by reactions not involving formation of carboxyl groups
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Abstract
The invention discloses a preparation method of 3-chloro-2, 4, 5-trifluoro benzoic acid, and the reaction equation is as follows: 3,4,5, 6-tetrafluorophthalonitrile in aprotic polar solvent as solvent in ammoniation reagentPreparing a compound of a formula (1); hydrolyzing and decarboxylating the compound of the formula (1) under the action of acid to prepare a compound of a formula (2); the compound of formula (2) and sodium nitrite are subjected to diazotization reaction and then subjected to Sandmeyer reaction to prepare the compound of formula (3). The method has the advantages of short process route, simple operation, high yield and industrial value.
Description
Technical Field
the invention relates to the field of pharmacy, in particular to a preparation method of 3-chloro-2, 4, 5-trifluoro benzoic acid.
Background
The 3-chloro-2, 4, 5-trifluorobenzoic acid is a key intermediate for synthesizing novel fluoroquinolone antibacterial drugs such as sitafloxacin, delafloxacin and the like, and has wide market development prospect.
The patents and literature also disclose several synthetic methods for preparing 3-chloro-2, 4, 5-trifluorobenzoic acid, but these methods have more or less disadvantages and are difficult to adapt to industrial scale-up, such as:
Irikura U, Suzue S, Murayama S, et al, Quinolonecoboxylic acid derivatives [ P ] Eur Pat Appl:195316,1986-09-24, using 3-chloro-4-fluoroaniline as the starting material, through amino protection, nitration, deprotection and chlorination series of reactions. The method has the advantages of long route, complex operation and low total yield.
Petersen U, Schrivewer M, Kysela E, et al, Process for preparing benzoic acid derivatives as antibacterial intermediates [ P ], Ger Offen 3631906,1988-05-31, using 2, 4-dichloro-5-fluorobenzoic acid as starting material, and preparing by nitration, reduction, diazotization and sandmeyer reaction. The method has the main disadvantages that: high-pressure reaction is needed in the reaction process, so that the safety risk is high, the equipment cost is high, and the requirement of industrial production is difficult to adapt.
Patent US5362909A discloses a process for preparing a target compound by chlorinating 2,4, 5-trifluorobenzoic acid as a starting material directly with chlorine, which process has the major disadvantages: the used starting materials are difficult to purchase and expensive, and chlorine gas adopted by the chlorination is a highly toxic gas, so that the requirements on equipment are high, and the investment cost is increased. Polychlorinated impurities are easily generated in the chlorination process, and are not easy to separate and need repeated recrystallization.
Patent US4885386 discloses a process for preparing a compound from 3,4,5, 6-tetrachloro-o-dibenzoic acid as starting material through fluorination, ammoniation, diazotization and sandmeyer reaction. The method has the main defects of harsh fluorination conditions, certain difficulty in scale-up production and low total yield.
disclosure of Invention
in view of the above-mentioned defects of the prior art, the present invention aims to provide a preparation method of 3-chloro-2, 4, 5-trifluorobenzoic acid, which has the advantages of short process route, simple operation, high yield and industrial value. .
the purpose of the invention is realized by the following technical scheme:
the preparation method of 3-chloro-2, 4, 5-trifluorobenzoic acid comprises the following reaction formula:
3,4,5, 6-tetrafluorophthalonitrile, and taking an aprotic polar solvent as a solvent to prepare the compound shown in the formula (1) under the action of an ammoniation reagent;
hydrolyzing and decarboxylating the compound of the formula (1) under the action of acid to prepare a compound of a formula (2);
The compound of formula (2) and sodium nitrite are subjected to diazotization reaction and then subjected to Sandmeyer reaction to prepare the compound of formula (3).
Further, the aprotic polar solvent is selected from one or more of N, N-dimethylformamide, acetonitrile, dioxane and dimethyl sulfoxide.
further, the ammoniating reagent is selected from ammonia water or liquid ammonia.
Further, the acid used in the preparation of the compound of formula (2) from the compound of formula (1) is selected from one or more of concentrated hydrochloric acid, concentrated sulfuric acid and concentrated nitric acid.
Further, a catalyst is added in the process of preparing the compound of the formula (3) from the compound of the formula (2), and the catalyst is halogenated copper.
Further, the halogenated copper is selected from one or more of cupric chloride dihydrate, cuprous chloride, anhydrous cupric chloride, cupric bromide and cupric iodide.
Furthermore, in the process of preparing the compound shown in the formula (1) from 3,4,5, 6-tetrafluorophthalonitrile, the reaction temperature is 90-110 ℃.
Further, in the process of preparing the compound of the formula (2) from the compound of the formula (1), the reaction temperature is 90-120 ℃.
further, in the process of preparing the compound of the formula (3) from the compound of the formula (2), the reaction temperature is-10 ℃ when the sodium nitrite aqueous solution is dripped, and the reaction temperature is kept at 0-45 ℃.
The reaction temperature is 90-120 ℃.
Further, when the compound of the formula (1) is prepared, the molar ratio of 3,4,5, 6-tetrafluorophthalonitrile to the ammoniation reagent is 1: 3-6;
When the compound of the formula (3) is prepared, the molar ratio of the compound of the formula (2) to the sodium nitrite to the copper chloride dihydrate is 1: 1-2: 5-10.
Due to the adoption of the technical scheme, the invention has the following advantages: the method has the advantages of short process route, simple operation, high yield and industrial value.
additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.
drawings
FIG. 1 shows the reaction equation for preparing 3-chloro-2, 4, 5-trifluorobenzoic acid.
Detailed Description
The invention is further illustrated by the following figures and examples.
Example 1:
As shown in fig. 1, the preparation of 3-chloro-2, 4, 5-trifluorobenzoic acid comprises the following steps:
Adding 0.15mol of 3,4,5, 6-tetrafluorophthalonitrile into 150g of N, N-dimethylformamide, heating to the internal temperature of 90 ℃, slowly dripping 0.45mol of ammonia water, keeping the temperature of 90 ℃ for reaction for 2 hours, cooling the reaction liquid to room temperature after the reaction is finished, slowly pouring the reaction liquid into 450g of ice water, filtering until the solid is completely separated out, washing the filter cake to be neutral by using a 5% sodium bicarbonate solution, and performing vacuum drying to obtain the compound solid of the formula (1).
Adding 0.04mol of the compound shown as the formula (1) at room temperature, adding 200g of concentrated hydrochloric acid, heating to 90 ℃, keeping the temperature until the raw materials disappear, cooling the reaction liquid to about 0 ℃ after the reaction is finished, adjusting the pH to 1-2 by using 30% liquid caustic soda, stirring for 1 hour, filtering out solids, extracting the filtrate by using 450g of ethyl acetate, concentrating an organic layer to the residual volume of 50ml, filtering, collecting and precipitating the solids, and drying to obtain the compound shown as the formula (2).
0.066mol of the compound of the formula (2), 0.33mol of copper chloride dihydrate and 240g of hydrochloric acid are added into a reaction bottle under stirring, the temperature is reduced to 0 ℃, and 0.066mol of sodium nitrite is dissolved into 30.8g of water to prepare a sodium nitrite solution. And (3) cooling the reaction liquid to-10 ℃, maintaining the internal temperature of-10 ℃, dropwise adding the prepared sodium nitrite solution, and after dropwise adding, heating the reaction liquid to 0 ℃ and preserving the temperature for 2-3 hours. Adding 400g of dichloromethane and 360g of water, stirring for 30 minutes, extracting, separating liquid, washing an organic layer once by using 40g of hydrochloric acid, concentrating an organic phase, dissolving the obtained solid in 30g of n-heptane for recrystallization, filtering and drying to obtain the compound shown in the formula (3).
Example 2:
As shown in fig. 1, the preparation of 3-chloro-2, 4, 5-trifluorobenzoic acid comprises the following steps:
Adding 0.15mol of 3,4,5, 6-tetrafluorophthalonitrile into 150g of acetonitrile, heating to 100 ℃ of internal temperature, slowly dropping 0.9mol of liquid ammonia, keeping the temperature at 110 ℃ for reaction for 2 hours, cooling the reaction solution to room temperature after the reaction is finished, slowly pouring the reaction solution into 450g of ice water, filtering after the solid is completely separated out, washing the filter cake to be neutral by using a 5% sodium bicarbonate solution, and drying in vacuum to obtain the compound shown in the formula (1).
Adding 0.04mol of the compound shown in the formula (1) at room temperature, adding 100g of concentrated sulfuric acid, heating to 120 ℃, and preserving heat until the raw materials disappear. After the reaction is finished, cooling the reaction liquid to room temperature, slowly pouring 200ml of ice-water mixture, cooling to 0 ℃, adjusting the pH to 1-2 with 30% liquid alkali, stirring for 1 hour, filtering out solids, extracting the filtrate with 450g of ethyl acetate, concentrating an organic layer to a residual volume of 50ml, filtering, collecting precipitated solids, and drying to obtain the compound of the formula (2).
adding 0.066mol of the compound shown in the formula (2), 0.66mol of cuprous chloride and 240g of hydrochloric acid into a reaction bottle while stirring, cooling to 0 ℃, and dissolving 0.132mol of sodium nitrite into 30.8g of water to prepare a sodium nitrite solution. And (3) heating the reaction liquid to 10 ℃, maintaining the internal temperature of 10 ℃, dropwise adding the prepared sodium nitrite solution, and after dropwise adding, heating the reaction liquid to 45 ℃ and preserving the temperature for 2-3 hours. Adding 400g of dichloromethane and 360g of water, stirring for 30 minutes, extracting, separating liquid, washing an organic layer once by using 40g of hydrochloric acid, concentrating an organic phase, dissolving the obtained solid in 30g of n-heptane for recrystallization, filtering and drying to obtain the compound shown in the formula (3).
Example 3:
adding 0.15mol of 3,4,5, 6-tetrafluorophthalonitrile into 150ml of dioxane, heating to 100 ℃ of internal temperature, slowly dropwise adding 0.6mol of ammonia water, keeping the temperature at 100 ℃ for reaction for 2 hours after the dropwise addition is finished, cooling the reaction liquid to room temperature after the reaction is finished, slowly pouring the reaction liquid into 450g of ice water, filtering after the solid is completely separated out, washing the filter cake with 5% sodium bicarbonate solution until the pH value is 6-7, and performing vacuum drying to obtain the compound shown in the formula (1).
Adding 0.04mol of the compound shown in the formula (1) at room temperature, adding 100g of concentrated nitric acid, heating to 100 ℃, and keeping the temperature until the raw materials disappear. After the reaction is finished, cooling the reaction liquid to room temperature, slowly pouring 200ml of ice-water mixture, cooling to 0 ℃, adjusting the pH to 1-2 with 30% liquid alkali, stirring for 1 hour, filtering out solids, extracting the filtrate with 450g of ethyl acetate, concentrating an organic layer to a residual volume of 50ml, filtering, collecting precipitated solids, and drying to obtain the compound of the formula (2).
0.066mol of the compound of the formula (2), 0.53mol of anhydrous copper dichloride and 240g of hydrochloric acid are added into a reaction bottle under stirring, the temperature is reduced to 0 ℃, and 0.99mol of sodium nitrite is dissolved into 30.8g of water to prepare a sodium nitrite solution. And (3) cooling the reaction liquid to-5 ℃, maintaining the internal temperature of-5 ℃, dropwise adding the prepared sodium nitrite solution, and after dropwise adding, heating the reaction liquid to 20 ℃ and preserving the temperature for 2-3 hours. Adding 400g of dichloromethane and 360g of water, stirring for 30 minutes, extracting, separating liquid, washing an organic layer once by using 40g of hydrochloric acid, concentrating an organic phase, dissolving the obtained solid in 30g of n-heptane for recrystallization, filtering and drying to obtain the compound shown in the formula (3).
example 4:
Adding 0.15mol of 3,4,5, 6-tetrafluorophthalonitrile into 150g of a mixture of N, N-dimethylformamide, acetonitrile, dioxane and dimethyl sulfoxide, heating to the internal temperature of 90 ℃, slowly dripping 0.45mol of ammonia water, keeping the temperature of 90 ℃ for reaction for 2 hours, cooling the reaction liquid to room temperature after the reaction is finished, slowly pouring the reaction liquid into 450g of ice water, filtering after the solid is completely separated out, washing the filter cake to be neutral by using a 5% sodium bicarbonate solution, and drying in vacuum to obtain the solid of the compound shown in the formula (1).
Adding 0.04mol of the compound shown as the formula (1) at room temperature, adding 200g of a mixture of hydrochloric acid, concentrated sulfuric acid and concentrated nitric acid, heating to 90 ℃, keeping the temperature until the raw materials disappear, cooling the reaction liquid to about 0 ℃ after the reaction is finished, adjusting the pH to 1-2 by using 30% liquid alkali, stirring for 1 hour, filtering out solids, extracting the filtrate by using 450g of ethyl acetate, concentrating an organic layer to a residual volume of 50ml, filtering, collecting separated solids, and drying to obtain the compound shown as the formula (2).
0.066mol of a 0.33mol mixture of the compound of the formula (2), copper chloride dihydrate, cuprous chloride, anhydrous copper chloride, copper bromide and copper iodide and 240g of hydrochloric acid are added into a reaction bottle under stirring, the temperature is reduced to 0 ℃, and 0.066mol of sodium nitrite is dissolved into 30.8g of water to prepare a sodium nitrite solution. And (3) cooling the reaction liquid to-10 ℃, maintaining the internal temperature of-10 ℃, dropwise adding the prepared sodium nitrite solution, and after dropwise adding, heating the reaction liquid to 0 ℃ and preserving the temperature for 2-3 hours. Adding 400g of dichloromethane and 360g of water, stirring for 30 minutes, extracting, separating liquid, washing an organic layer once by using 40g of hydrochloric acid, concentrating an organic phase, dissolving the obtained solid in 30g of n-heptane for recrystallization, filtering and drying to obtain the compound shown in the formula (3).
Example 5:
Adding 0.15mol of 3,4,5, 6-tetrafluoro phthalic nitrile into 150g of N, N-dimethylformamide, heating to 100 ℃ of internal temperature, slowly dripping 0.6mol of ammonia water, keeping the temperature at 100 ℃ for reaction for 2 hours after dripping is finished, cooling the reaction solution to room temperature after the reaction is finished, slowly pouring the reaction solution into 450g of ice water, filtering until solid is completely separated out, washing a filter cake to be neutral by using 5% sodium bicarbonate solution, and drying in vacuum to obtain 23.5g of the compound solid of the formula (1), wherein the yield is 80%.
Adding 0.04mol of the compound shown as the formula (1) at room temperature, adding 200g of concentrated hydrochloric acid, heating to 100 ℃, keeping the temperature until the raw materials disappear, after the reaction is finished, cooling the reaction liquid to about 0 ℃, adjusting the pH to 1-2 by using 30% liquid caustic soda, stirring for 1 hour, filtering out solids, extracting the filtrate by using 450g of ethyl acetate, concentrating an organic layer to the residual volume of 50ml, filtering, collecting and precipitating solids, and drying to obtain 5.8g of the compound shown as the formula (2) with the yield of 76%.
0.066mol of the compound of the formula (2), 0.53mol of copper chloride dihydrate and 240g of hydrochloric acid are added into a reaction bottle under stirring, the temperature is reduced to 0 ℃, and 0.11mol of sodium nitrite is dissolved into 30.8g of water to prepare a sodium nitrite solution. And (3) cooling the reaction liquid to-5-0 ℃, maintaining the internal temperature of-10 ℃, dropwise adding the prepared sodium nitrite solution, and after dropwise adding, heating the reaction liquid to 20-25 ℃, and preserving the temperature for 2-3 hours. Adding 400g of dichloromethane and 360g of water, stirring for 30 minutes, extracting, separating liquid, washing an organic layer once by using 40g of hydrochloric acid, concentrating an organic phase, dissolving the obtained solid in 30g of n-heptane for recrystallization, filtering and drying to obtain 9.7g of the compound shown in the formula (3) with the yield of 70%.
Although the present invention has been described to a certain degree, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention, and equivalents thereof fall within the scope of the invention defined by the appended claims.
Claims (10)
- a process for producing 3-chloro-2, 4, 5-trifluorobenzoic acid, characterized in that the reaction equation is as follows:3,4,5, 6-tetrafluorophthalonitrile, and taking an aprotic polar solvent as a solvent to prepare the compound shown in the formula (1) under the action of an ammoniation reagent;Hydrolyzing and decarboxylating the compound of the formula (1) under the action of acid to prepare a compound of a formula (2);The compound of formula (2) and sodium nitrite are subjected to diazotization reaction and then subjected to Sandmeyer reaction to prepare the compound of formula (3).
- 2. The method for preparing 3-chloro-2, 4, 5-trifluorobenzoic acid according to claim 1, wherein the aprotic polar solvent is one or more selected from the group consisting of N, N-dimethylformamide, acetonitrile, dioxane, and dimethylsulfoxide.
- 3. the method of claim 1, wherein the ammoniating agent is selected from ammonia or liquid ammonia.
- 4. The method for preparing 3-chloro-2, 4, 5-trifluorobenzoic acid according to claim 1, wherein the acid used in the preparation of the compound of formula (2) from the compound of formula (1) is selected from one or more of concentrated hydrochloric acid, concentrated sulfuric acid and concentrated nitric acid.
- 5. The method according to claim 1, wherein a catalyst is further added during the preparation of the compound of formula (3) from the compound of formula (2), and the catalyst is copper halide.
- 6. The method of claim 5, wherein the copper halide is selected from the group consisting of cupric chloride dihydrate, cuprous chloride, anhydrous cupric chloride, cupric bromide, and cupric iodide.
- 7. The method for producing 3-chloro-2, 4, 5-trifluorobenzoic acid according to claim 1, wherein the reaction temperature is 90 to 110 ℃ in the production of the compound of formula (1) from 3,4,5, 6-tetrafluorophthalonitrile.
- 8. the method for preparing 3-chloro-2, 4, 5-trifluorobenzoic acid according to claim 1, wherein the reaction temperature is 90-120 ℃ during the process of preparing the compound of formula (2) from the compound of formula (1).
- 9. The method for preparing 3-chloro-2, 4, 5-trifluorobenzoic acid according to claim 1, wherein in the process of preparing the compound of formula (3) from the compound of formula (2), the temperature is-10 to 10 ℃ when the aqueous solution of sodium nitrite is dropwise added, and the reaction temperature is kept at 0 to 45 ℃.The reaction temperature is 90-120 ℃.
- 10. the process for producing 3-chloro-2, 4, 5-trifluorobenzoic acid according to claim 1, wherein,When the compound of the formula (1) is prepared, the molar ratio of 3,4,5, 6-tetrafluorophthalonitrile to an ammoniation reagent is 1: 3-6;When the compound of the formula (3) is prepared, the molar ratio of the compound of the formula (2) to the sodium nitrite to the copper chloride dihydrate is 1: 1-2: 5-10.
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Application publication date: 20191217 |