A method for treating waste residue from the production of amiloride

Abstract

The invention discloses a method for treating waste residue produced by amiloride, which is raw material of waste residue produced by amiloride, and the waste residue is converted into tetrachloropyralid through deamination and chlorination reaction, and this product can be circulated in the preparation process of amiloride, thereby completing the effective circulation of raw material-product-waste residue-raw material-product, realizing the atomic economy of chemical reaction and the resource utilization of material, avoiding the damage of waste residue to the environment, and having high economic and environmental benefits. And the route of the present invention avoids the dangerous diazotization process in the traditional process route, while avoiding the generation of a large amount of waste acid and waste water, which is greener, efficient, safe and reliable. The overall process of the present invention is simple, and the reaction conditions are mild. By adjusting the reaction conditions, the product yield is higher and the quality is better, which is conducive to industrialized production.

Description

Technical Field

[0001] The invention relates to a method for treating waste residues from the production of amiloride, and in particular to a method for treating waste residues from the production of amiloride by converting the waste residues into tetraclopyralid through deamination reaction and chlorination reaction for resource reuse. Background Art

[0002] Amiloride, chemically known as 4-amino-3,5,6-trichloropyridine carboxylic acid, is a systemic herbicide with broad market prospects. Amiloride is generally prepared by the aminolysis reaction of 3,4,5,6-tetrachloropyridine carboxylic acid and ammonia water. During the reaction, amino substitution of the chlorine group at the 4th position mainly occurs, and amino substitution of the chlorine groups at the 3rd, 5th and 6th positions also occurs. The substitution reaction at the 6th position is particularly obvious, and waste residue of amiloride will be produced in the crystallization process.

[0003] The primary production waste residue of amiloride is mainly composed of 4-amino-3,5,6-trichloropicolinate ammonium salt and 6-amino-3,4,5-trichloropicolinate ammonium salt. The secondary residue produced after the primary production waste residue is separated and purified from amiloride contains a small amount of 4-amino-3,5,6-trichloropicolinate (amilopyralid) and most of 6-amino-3,4,5-trichloropicolinate. The primary production waste residue of amiloride and the secondary residue produced after the primary production waste residue is separated and purified from amiloride are collectively referred to as amiloride production waste residue, which may also be referred to as amiloride waste residue.

[0004] There are few domestic and foreign literature and patent reports on how to treat the waste residue from the production of amiloride. Patents CN104649965 and CN107474013 convert the waste residue from amiloride into its industrial production intermediate 3,4,5,6-tetrachloropyridine carboxylic acid, and the processes are all diazotization processes, which are highly dangerous, with a large amount of waste acid, and greater risks in terms of safety and environmental protection. Summary of the invention

[0005] The object of the present invention is to provide a method for treating waste residue from the production of amiloride. The method uses waste residue from the production of amiloride as a raw material, converts the waste residue into tetrachloropyralid through deamination and chlorination reactions, and the product can be recycled in the preparation process of amiloride, thereby completing the effective cycle of raw material-product-waste residue-raw material-product, realizing the atomic economy of chemical reactions and resource utilization of materials, avoiding the damage of waste residue to the environment, and having high economic and environmental benefits.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] A method for treating waste residues from the production of amiloride comprises the steps of performing a deamination reaction on the waste residues from the production of amiloride to obtain an intermediate, and then performing a chlorination reaction on the intermediate to obtain tetrachloropyralid.

[0008] Furthermore, the amiloride production waste residue includes amiloride primary production waste residue and / or amiloride primary production waste residue produced after purification, and the waste residue contains components such as 6-amino-3,4,5-trichloropyridine carboxylic acid and amiloride carboxylic acid, mainly 6-amino-3,4,5-trichloropyridine carboxylic acid.

[0009] Furthermore, the deamination reaction refers to: the waste residue from the production of amiloride reacts with a deaminating agent to obtain an intermediate. The chlorination reaction refers to: the intermediate obtained by the deamination reaction further reacts with a chlorinating agent to obtain tetrachloropyralid.

[0010] Furthermore, the deamination agent is pyrylium tetrafluoroborate, and the structural formula of the pyrylium tetrafluoroborate is .

[0011] Further, taking 6-amino-3,4,5-trichloropicolinic acid as an example, the reaction formula of the present invention is as follows:

[0012]

[0013] Furthermore, the molar ratio of the waste residue from the production of amiloride to the deamination agent is 1:1-1.5, for example, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5.

[0014] Furthermore, the deamination reaction is carried out in the presence of a catalyst, the catalyst is a metal halide, the halide can be chloride, fluoride, bromide, etc., and the metal of the metal halide can be copper, cesium, etc.

[0015] Preferably, the metal halide is a metal chloride, such as cupric chloride, cuprous chloride, cesium chloride, etc., more preferably cuprous chloride.

[0016] Further, the molar ratio of the catalyst for the deamination reaction to the waste residue from the production of amiloride is 0.1-1:1, for example, 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, preferably 0.2:1.

[0017] Further, the temperature of the deamination reaction is 30-80°C, for example, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, preferably 50-60°C.

[0018] Further, the chlorination reaction is carried out under a chlorination reagent, wherein the chlorination reagent is hydrogen chloride gas, magnesium chloride, trimethylchlorosilane, etc., wherein hydrogen chloride gas is more environmentally friendly. The chlorination reagent can be added all at once, continuously, or in batches.

[0019] Furthermore, the molar ratio of the waste residue from the production of amiloride to the chlorination reagent is 1:1-1.5, for example, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5.

[0020] Further, the temperature of the chlorination reaction is 80-140°C, for example 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, preferably 80-120°C.

[0021] Furthermore, the deamination reaction and the chlorination reaction are both carried out in the presence of a solvent, and the solvents for the deamination reaction and the chlorination reaction can be selected from polar aprotic solvents, such as acetonitrile, benzonitrile, o-xylene, and the like.

[0022] Furthermore, the deamination reaction and the chlorination reaction are preferably carried out in the same reaction vessel. After the production waste residue is subjected to the deamination reaction to obtain an intermediate, a chlorination reagent can be further added to the reaction product for reaction. Therefore, the deamination reaction and the chlorination reaction are preferably carried out in the same solvent. The solvent provides a reaction medium for the reaction, and its amount can be selected as needed. Generally, the mass ratio of the amiloride production waste residue to the solvent is 1:4-5.

[0023] The advantages of the present invention are:

[0024] 1. The present invention uses the waste residue from the production of amiloride as raw material, and converts the waste residue into tetrachloropyralid through deamination and chlorination reactions. The product can be recycled in the preparation process of amiloride, thereby completing the effective cycle of raw material-product-waste residue-raw material-product, achieving the atomic economy of chemical reactions and resource utilization of materials, avoiding the damage of waste residue to the environment, and having high economic and environmental benefits.

[0025] 2. The present invention replaces the traditional diazotization reaction with a deamination reaction, which reduces the risk and improves the safety of the reaction. At the same time, it avoids the problem of generating a large amount of waste acid and waste water during the diazotization reaction, and is more green, economical, efficient, safe and reliable.

[0026] 3. The overall process of the present invention is simple, the reaction conditions are mild, and it is economical and environmentally friendly. By optimizing the reaction conditions, the conversion rate and selectivity of the deamination reaction and the chlorination reaction can be improved, the yield and purity of the obtained product can be improved, the product quality can be improved, and it is conducive to industrial production. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the examples. It should be understood that the following description is only for the purpose of explaining the present invention and does not limit its content. Unless otherwise specified, the concentrations used are all mass percentage concentrations.

[0028] The invention uses the waste residue of amiloride production as raw material, obtains an intermediate through deamination reaction, and obtains the product tetrachloropyralid through chlorination of the intermediate. The main components of the waste residue are 6-amino-3,4,5-trichloropyralid acid and its isomers, with a molecular weight of 242 g / mol, and the molecular weight of tetrachloropyralid acid is 260.89 g / mol.

[0029] Taking 6-amino-3,4,5-trichloropicolinic acid as an example, the reaction formula is as follows:

[0030]

[0031] Several preferred embodiments of the present invention are listed below to illustrate the technical solution of the present invention in detail.

[0032] In the following examples, the calculation formula for the yield of tetrachloropyralid is:

[0033] The yield of tetrachloropyralid acid = [m (tetrachloropyralid acid) × Wt (tetrachloropyralid acid) / M (tetrachloropyralid acid) / n (6-amino-3,4,5-trichloropyralid acid) × 100%], wherein m (tetrachloropyralid acid) represents the mass of tetrachloropyralid acid, Wt (tetrachloropyralid acid) represents the mass content of tetrachloropyralid acid, M (tetrachloropyralid acid) represents the relative molecular mass of tetrachloropyralid acid, and n (6-amino-3,4,5-trichloropyralid acid) represents the molar amount of 6-amino-3,4,5-trichloropyralid acid.

[0034] The method for determining the content of tetrachloropyralid acid is liquid phase quantitative detection, and the method for calculating the selectivity of tetrachloropyralid acid is: [tetrachloropyralid acid yield / 6-amino-3,4,5-trichloropyralid acid conversion rate].

[0035] Example 1

[0036] 100 g of production waste residue, 500 g of acetonitrile and 7.87 g (0.2 mol equivalent) of cuprous chloride were put into a glass four-necked flask, stirring was started, the temperature was raised to 50-60° C. with an oil bath, 80.06 g of pyrylium tetrafluoroborate was added, the reaction was kept warm for 2 h, and then a sample was taken for detection of no conversion, and no conversion <1% was qualified; after no conversion was qualified, the oil bath was heated to 100-120° C., 17.38 g of hydrogen chloride gas was introduced into the system for chlorination reaction, and the chlorination reaction temperature was controlled not to exceed 120° C. After the introduction was completed, the reaction was kept warm for 1 h, and no conversion <1% was sampled for qualification, and the qualified reaction solution was subjected to desolventization, cooling crystallization, filtration and drying to obtain 101.26 g of tetrachloropyralid acid dry product with a content of 95.3%, a selectivity of 95.63% and a yield of 94.03%.

[0037] Example 2

[0038] The operation was carried out according to the method of Example 1, except that the amount of cuprous chloride added was 3.93 g (0.1 mol equivalent). The specific steps were as follows: 100 g of waste residue, 500 g of acetonitrile, and 3.93 g of cuprous chloride (0.1 mol equivalent) were put into a glass four-necked flask, stirring was started, the oil bath was heated to 50-60°C, 80.06 g of pyrylium tetrafluoroborate was added, and the reaction was kept warm for 2 hours; the oil bath was heated to 100-120°C, 17.38 g of hydrogen chloride gas was introduced into the system for chlorination reaction, the chlorination reaction temperature was controlled not to exceed 120°C, the introduction was completed, the temperature was kept warm for 1 hour, and the sample was not converted to <1% and was qualified. After the qualified reaction solution was subjected to desolventization, cooling crystallization, filtration, and drying, 98.54 g of tetrachloropyralid acid dry product was obtained, with a content of 93.08%, a selectivity of 93.75%, and a yield of 89.37%.

[0039] Example 3

[0040] The operation was carried out according to the method of Example 1, except that cuprous chloride was replaced with 0.2 mol equivalent of cupric chloride. The specific steps are as follows: 100 g of waste residue, 500 g of acetonitrile, and 10.68 g of cupric chloride (0.2 mol equivalent) were put into a glass four-necked flask, stirring was started, the oil bath was heated to 50-60°C, 80.06 g of pyrylium tetrafluoroborate was added, and the reaction was kept warm for 2 hours; the oil bath was heated to 100-120°C, 17.38 g of hydrogen chloride gas was introduced into the system for chlorination reaction, the chlorination reaction temperature was controlled not to exceed 120°C, the introduction was completed, the temperature was kept warm for 1 hour, and the sample was not converted to <1% as qualified, and the qualified reaction solution was subjected to desolventization, cooling crystallization, filtration, and drying to obtain 95.67 g of tetrachloropyralid acid dry product, with a content of 93.2%, a selectivity of 90.88%, and a yield of 86.88%.

[0041] Example 4

[0042] The operation was carried out according to the method of Example 1, except that cuprous chloride was replaced with 0.2 mol equivalent of cesium chloride. The specific steps are as follows: 100 g of waste residue, 500 g of acetonitrile, and 13.38 g of cesium chloride (0.2 mol equivalent) were put into a glass four-necked flask, stirring was started, the oil bath was heated to 50-60 ° C, 80.06 g of pyrylium tetrafluoroborate was added, and the reaction was kept warm for 2 hours; the oil bath was heated to 100-120 ° C, 17.38 g of hydrogen chloride gas was introduced into the system for chlorination reaction, and the chlorination reaction temperature was controlled not to exceed 120 ° C. After the introduction was completed, the temperature was kept warm for 1 hour, and the sample was not converted to <1% as qualified. After the qualified reaction solution was subjected to desolventization, cooling crystallization, filtration, and drying, 94.21 g of tetrachloropyralid acid dry product was obtained, with a content of 93.9%, a selectivity of 90.82%, and a yield of 86.20%.

[0043] Example 5

[0044] The operation was carried out according to the method of Example 1, except that the temperature of the deamination reaction was 30-40°C. The specific steps were as follows: 100g of waste residue, 500g of acetonitrile, and 7.87g (0.2mol equivalent) of cuprous chloride were put into a glass four-necked flask, stirring was started, the temperature was raised to 30-40°C with an oil bath, 80.06g of pyrylium tetrafluoroborate was added, and the reaction was kept warm for 2h, and the reaction was not qualified; after the reaction was not qualified, the oil bath was heated to 100-120°C, and 17.38g of hydrogen chloride gas was introduced into the system for chlorination reaction, and the chlorination reaction temperature was controlled not to exceed 120°C. After the introduction was completed, the reaction was kept warm for 1h, and the reaction was not qualified if the sample was <1%. After the reaction solution was qualified, 92.93g of tetrachloropyralid acid dry product was obtained after desolventizing, cooling crystallization, filtering, and drying, with a content of 91.3%, a selectivity of 91.54%, and a yield of 82.67%.

[0045] Example 6

[0046] The operation was carried out according to the method of Example 1, except that the temperature of the deamination reaction was 70-80°C. The specific steps were as follows: 100g of waste residue, 500g of acetonitrile, and 7.87g (0.2mol equivalent) of cuprous chloride were put into a glass four-necked flask, stirring was started, the temperature was raised to 70-80°C with an oil bath, 80.06g of pyrylium tetrafluoroborate was added, and the reaction was kept warm for 2h, and the reaction was not qualified; after the reaction was not qualified, the oil bath was heated to 100-120°C, and 17.38g of hydrogen chloride gas was introduced into the system for chlorination reaction, and the chlorination reaction temperature was controlled not to exceed 120°C. After the introduction was completed, the reaction was kept warm for 1h, and the reaction was not qualified if the sample was <1%. After the reaction solution was qualified, 90.08g of tetrachloropyralid acid dry product was obtained after desolventizing, cooling crystallization, filtering, and drying, with a content of 89.4%, a selectivity of 80.81%, and a yield of 78.47%.

[0047] Example 7

[0048] The deamination reaction was carried out according to the method of Example 1. After the reaction was not qualified, the oil bath was heated to 130-140°C, and 17.38g of hydrogen chloride gas was introduced into the system for chlorination reaction. The chlorination reaction temperature was controlled not to exceed 140°C. After the introduction was completed, the reaction was kept warm for 1h. The reaction was sampled and the reaction was not qualified if the conversion was less than 1%. The reaction solution was desolventized, cooled and crystallized, filtered, and dried to obtain 90.71g of tetrachloropyralid acid dry product with a content of 86.1%, a selectivity of 78.37%, and a yield of 76.1%.

[0049] Example 8

[0050] The deamination reaction was carried out according to the method of Example 1. After the reaction was not qualified, the oil bath was heated to 100-120°C, and 52.96g of magnesium chloride solid was added to the system in batches for chlorination reaction. The chlorination reaction temperature was controlled not to exceed 120°C, and the reaction was kept warm for 1h. The reaction was not qualified if the reaction was less than 1%. After the reaction solution was qualified, it was desolventized, cooled and crystallized, filtered, and dried to obtain 97.71g of tetrachloropyralid acid dry product with a content of 92.1%, a selectivity of 91.24%, and a yield of 87.69%.

[0051] Example 9

[0052] The operation was carried out according to the method of Example 1, except that the amount of cuprous chloride added was 19.67 g (0.5 mol equivalent). The specific steps are: 100 g of waste residue, 500 g of acetonitrile, and 19.67 g of cuprous chloride (0.5 mol equivalent) were put into a glass four-necked flask, stirring was started, the oil bath was heated to 50-60 ° C, 80.06 g of pyrylium tetrafluoroborate was added, and the reaction was kept warm for 2 hours, and it was not qualified; after it was not qualified, the oil bath was heated to 100-120 ° C, and 17.38 g of hydrogen chloride gas was introduced into the system for chlorination reaction, and the chlorination reaction temperature was controlled not to exceed 120 ° C. After the introduction was completed, the temperature was kept warm for 1 hour, and the sample was not converted to <1% for qualified, and the qualified reaction solution was subjected to desolventization, cooling crystallization, filtration, and drying to obtain 100.83 g of tetrachloropyralid acid dry product, with a content of 94.92%, a selectivity of 95.13%, and a yield of 93.26%.

[0053] Example 10

[0054] The operation was carried out according to the method of Example 1, except that the amount of cuprous chloride added was 39.34 g (1.0 mol equivalent). The specific steps are: 100 g of waste residue, 500 g of acetonitrile, and 39.34 g (1.0 mol equivalent) of cuprous chloride were put into a glass four-necked flask, stirring was started, the oil bath was heated to 50-60 ° C, 80.06 g of pyrylium tetrafluoroborate was added, and the reaction was kept warm for 2 hours, and it was not qualified; after it was not qualified, the oil bath was heated to 100-120 ° C, and 17.38 g of hydrogen chloride gas was introduced into the system for chlorination reaction, and the chlorination reaction temperature was controlled not to exceed 120 ° C. After the introduction was completed, the temperature was kept warm for 1 hour, and the sample was not converted to <1% for qualified, and the qualified reaction solution was subjected to desolventization, cooling crystallization, filtration, and drying to obtain 100.95 g of tetrachloropyralid acid dry product, with a content of 95.3%, a selectivity of 95.63%, and a yield of 93.74%.

[0055] Embodiment 11

[0056] The deamination reaction was carried out according to the method of Example 1. If the reaction was not qualified, the oil bath was heated to 100-120°C, and 60.44g of trimethylsilyl chloride was added dropwise to the system for chlorination reaction. The temperature of the addition process was controlled not to exceed 120°C. After the addition was completed, the mixture was kept warm for 1h. If the reaction was not qualified by less than 1%, the reaction solution was desolventized, cooled and crystallized, filtered, and dried to obtain 99.71g of tetrachloropyralid acid dry product with a content of 94.1%, a selectivity of 95.13%, and a yield of 91.43%.

[0057] Example 12

[0058] The method of Example 1 was followed, except that o-xylene was used as the solvent. The specific steps were as follows: 100 g of waste residue, 500 g of o-xylene, and 7.87 g (0.2 mol equivalent) of cuprous chloride were put into a glass four-necked flask, stirring was started, the temperature was raised to 50-60°C with an oil bath, 80.06 g of pyrylium tetrafluoroborate was added, and the reaction was kept warm for 2 hours, and the reaction was not qualified; after the reaction was not qualified, the temperature of the oil bath was raised to 100-120°C, and 17.38 g of hydrogen chloride gas was introduced into the system for chlorination reaction, and the temperature of the chlorination reaction was controlled not to exceed 120°C. After the introduction was completed, the reaction was kept warm for 1 hour, and the reaction was not qualified if the sample was <1%. After the reaction solution was qualified, 99.54 g of tetrachloropyralid acid dry product was obtained after desolventizing, cooling and crystallizing, filtering, and drying, with a content of 95.08%, a selectivity of 95.95%, and a yield of 92.22%.

[0059] Embodiment 13

[0060] The method of Example 1 was followed, except that benzonitrile was used as the solvent. The specific steps were as follows: 100 g of waste residue, 500 g of benzonitrile, and 7.87 g (0.2 mol equivalent) of cuprous chloride were put into a glass four-necked flask, stirring was started, the temperature was raised to 50-60°C with an oil bath, 80.06 g of pyrylium tetrafluoroborate was added, and the reaction was kept warm for 2 hours, and the reaction was not qualified; after the reaction was not qualified, the temperature of the oil bath was raised to 100-120°C, and 17.38 g of hydrogen chloride gas was introduced into the system for chlorination reaction, and the temperature of the chlorination reaction was controlled not to exceed 120°C. After the introduction was completed, the reaction was kept warm for 1 hour, and the reaction was not qualified if the sample was <1%. After the reaction solution was qualified, 100.03 g of tetrachloropyralid acid dry product was obtained after desolventizing, cooling and crystallizing, filtering, and drying, with a content of 95.06%, a selectivity of 96.19%, and a yield of 92.66%.

[0061] Embodiment 14

[0062] The operation was carried out according to the method of Example 1, except that the chlorination reaction temperature was 80-100°C. After the deamination reaction failed to pass, the oil bath was heated to 80-100°C, and 17.38g of hydrogen chloride gas was introduced into the system for chlorination reaction, and the chlorination reaction temperature was controlled not to exceed 100°C. After the introduction was completed, the temperature was kept for 1h, and the sample was not converted to <1% as qualified. After the qualified reaction solution was desolventized, cooled and crystallized, filtered, and dried, 100.2g of tetrachloropyralid acid dry product was obtained, with a content of 94.96%, a selectivity of 96.70%, and a yield of 92.72%.

Claims

1. A method for treating waste residue from the production of amiloride, characterized in that: The invention comprises the steps of subjecting amitraz production waste residue to deamination reaction to obtain an intermediate, and then subjecting the intermediate to chlorination reaction to obtain tetrachloropyralid. The deamination agent used in the deamination reaction is pyrylium tetrafluoroborate, and the deamination reaction is carried out in the presence of a catalyst, which is cupric chloride, cuprous chloride or cesium chloride. The molar ratio of the amitraz production waste residue to the deamination agent is 1:1-1.4, and the molar ratio of the deamination reaction catalyst to the amitraz production waste residue is 0.1-1:

1. The chlorination reaction is carried out in the presence of a chlorination reagent, which is hydrogen chloride gas, magnesium chloride or trimethylsilyl chloride. The temperature of the deamination reaction is 50-60°C; and the temperature of the chlorination reaction is 80-120°C.

2. The processing method according to claim 1, characterized in that: The amiloride production waste residue includes amiloride primary production waste residue and / or amiloride primary production waste residue generated after purification of the amiloride primary production waste residue.

3. The processing method according to claim 1, characterized in that: The catalyst is cuprous chloride.

4. The processing method according to claim 1, characterized in that: The molar ratio of the catalyst for the deamination reaction to the waste residue from the production of amiloride is 0.2:

1.

5. The processing method according to claim 1, characterized in that: The molar ratio of the waste residue from the production of amiloride to the chlorination reagent is 1:1-1.

5.

6. The processing method according to claim 1, characterized in that: Both the deamination reaction and the chlorination reaction are carried out in the presence of a solvent.

7. The processing method according to claim 6, characterized in that: The solvents for the deamination reaction and the chlorination reaction are both selected from polar aprotic solvents.

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