阅读说明：本技术 3，5-取代-4-氨基三氟苯乙酮及其衍生物的制备方法 (Preparation method of 3, 5-substituted-4-amino trifluoro acetophenone and its derivative ) 是由 张凌霄 蔡刚华 于 2021-08-18 设计创作，主要内容包括：本申请涉及有机制药合成领域,具体涉及3,5-取代-4-氨基三氟苯乙酮及其衍生物的制备方法,其中3,5-取代-4-氨基三氟苯乙酮的制备方法,以,邻位二取代对的苯胺为原料,经氨基保护、酰基化反应、氨基脱保护三步,得到4-氨基的三氟苯乙酮,该反应原料简单易得,收率较高,反应条件温和,具有较好的工业运用前景。另外,在上述反应的基础上,对3,5-取代-4-氨基三氟苯乙酮进一步通过氨基重氮化的方式制备得到3,5-取代-4-氨基三氟苯乙酮的衍生物,在工业上有较大的运用前景。(The application relates to the field of organic pharmaceutical synthesis, in particular to a preparation method of 3, 5-substituted-4-amino trifluoroacetophenone and derivatives thereof, wherein the preparation method of the 3, 5-substituted-4-amino trifluoroacetophenone takes ortho-position disubstituted p-aniline as a raw material, and the amino protection, acylation reaction and amino deprotection are carried out to obtain the 4-amino trifluoroacetophenone. In addition, on the basis of the reaction, the 3, 5-substituted-4-amino trifluoro acetophenone derivatives are prepared by amino diazotization, and have a wide application prospect in industry.)

A preparation method of 1.3, 5-substituted-4-amino trifluoro acetophenone is characterized in that the reaction steps are shown in formula I,

the reaction comprises the following steps:

s1, protecting the amino group of the compound I through an acylation protection reagent through an acylation reaction to obtain a compound II;

s2, under the catalysis of Lewis acid, connecting trifluoroacetyl group on the para position of amino group of trifluoroacetyl compound to compound II to obtain compound III;

s3, hydrolyzing the compound III to obtain a compound IV;

wherein the trifluoroacetyl compound is any one of trifluoroacetyl chloride, trifluoroacetyl bromide, trifluoroacetate and trifluoroacetic anhydride, and in the compound I, R is₁，R₂is-Cl, -Br, -F, -CF₃One of (1); r₃Is methyl, trifluoromethyl or tert-butyl; r₃Is one of-H, -Cl, -Br and-F; r₄Is any one of fluorine, chlorine, bromine, iodine, hydroxyl and hydrogen.

2. The method for preparing 3, 5-substituted-4-amino trifluoroacetophenone according to claim 1, wherein in step S1, the acylation protecting agent is acetic anhydride, and the amount of the acylation protecting agent is 1 to 1.5 times that of the compound I.

3. The method for preparing 3, 5-substituted-4-amino trifluoroacetophenone according to claim 1, wherein in step S2, the trifluoroacetyl compound is trifluoroacetyl chloride.

4. The method for preparing 3, 5-substituted-4-amino trifluoroacetophenone according to claim 2, wherein in step S2, the lewis acid is aluminum chloride or zinc chloride.

5. The process for producing 3, 5-substituted-4-aminotrifluoroacetophenone according to claim 4, wherein step S2 is carried out in a solvent system immiscible with water, and after the reaction is completed, the system obtained in step S1 is washed with an aqueous solution of a base I to a pH of more than 6.4, and the organic phase is removed from the water and retained.

6. The method for preparing 3, 5-substituted-4-amino trifluoroacetophenone according to claim 1, wherein in step S2, the mass ratio of the compound II, the Lewis acid and the trifluoroacetyl compound is 1: 2-5.

7. The method for preparing 3, 5-substituted-4-amino trifluoroacetophenone according to claim 1, wherein the hydrolysis is carried out in step S3 by catalysis with a base II, wherein the base II is sodium hydroxide or potassium hydroxide.

8. The method for preparing 3, 5-substituted-4-amino trifluoroacetophenone according to claim 7, wherein in step S3, the compound III is added to an aqueous solution of 5 to 20 mass% of a base II for reaction.

9. The method for preparing 3, 5-substituted-4-amino trifluoroacetophenone according to claim 8, wherein the mass ratio of the base II to the compound III is (1-1.5): 1.

A method for producing a 3, 5-substituted-4-amino trifluoroacetophenone derivative, characterized by comprising the steps of producing a 3, 5-substituted-4-amino trifluoroacetophenone derivative by the production method according to any one of claims 1 to 9, diazotizing the amino group, and substituting the amino group with any one of hydrogen, hydroxyl, fluorine, chlorine, and bromine.

Technical Field

The application relates to the field of organic pharmaceutical synthesis, in particular to a preparation method of 3, 5-substituted-4-amino trifluoro acetophenone and derivatives thereof.

Background

The 3, 5-substituted trifluoroacetyl ketone compound and the 4-substituted derivative thereof are important pharmaceutical intermediates, and specific applications of the trifluoroacetyl ketone compound and the 4-substituted derivative are listed as follows:

1. the 3 ', 5' -dichloro-2, 2, 2-trifluoro acetophenone is one kind of miticide, pesticide and core intermediate for preparing important pesticide, such as fluralin, fluxapyroxamide, etc.

Currently, 3, 5-dichlorotrifluoroacetophenone is generally prepared by the following two ways:

(i) reacting 3, 5-dichlorobenzaldehyde with trifluoromethyl silane, and performing condensation reaction on benzaldehyde to prepare the trifluoroacetophenone, wherein the reaction path is shown as a formula II:

(ii) the method is characterized in that 3, 5-dichlorobromobenzene and a trifluoromethyl acetyl compound are subjected to bromine substitution reaction under the catalysis of strong alkali, and specifically shown in a formula III:

in the two reactions, the yield of the general formula II is slightly higher and is about 60 percent, but the two raw materials are not easy to obtain, the yield of the formula III is about 36 percent, the reaction conditions are harsh, and the two methods are not suitable for industrial production.

2. 1- (3, 5-dichloro-4-fluorophenyl) -2 ', 2 ', 2 ' -trifluoroacetone is an important pharmaceutical intermediate and can be used for synthesizing a series of novel insecticides and acaricides, for example, precursors of the synthesis of saralaina and isocycloseramim are all 1- (3, 5-dichloro-4-fluorophenyl) -2,2, 2-trifluoroacetone.

The preparation method of the 1- (3, 5-dichloro-4-fluorophenyl) -2 ', 2 ', 2 ' -trifluoroacetone is similar to that of the 3, 5-dichlorotrifluoroacetophenone and can be prepared by two methods in the 3, 5-dichlorotrifluoroacetophenone, but the preparation method is similar to that of the 3, 5-dichlorotrifluoroacetophenone, has the problems of difficult raw material source and low yield, and is not suitable for industrial production.

3. 3,4, 5-trichloro-trifluoroacetone is a core intermediate of lotilanide serving as an insecticide for pets, and is similar to the compound, the compound is generally prepared by taking 3,4, 5-trichlorobromobenzene as a raw material according to a method in a preparation method (ii) of 3, 5-dichlorotrifluoroacetophenone, isopropyl magnesium chloride needs to be prepared in a tetrahydrofuran solution for reaction, and then the reaction is carried out, and the raw material is not easy to obtain, and the reaction conditions are harsh, so that the compound is not suitable for industrial production.

In summary, no better industrial production method exists for 3, 5-substituted trifluoroacetophenone and derivatives thereof.

Disclosure of Invention

The application provides a preparation method of a 3, 5-substituted trifluoroacetophenone compound and a derivative thereof, which has the advantages of better yield, simpler raw material source and milder reaction conditions.

Firstly, the application provides a preparation method of 3, 5-substituted-4-amino trifluoro acetophenone, the reaction steps are shown in formula I,

the reaction comprises the following steps:

s1, protecting the amino group of the compound I through an acylation protection reagent through an acylation reaction to obtain a compound II;

s2, under the catalysis of Lewis acid, connecting trifluoroacetyl group on the para position of amino group of trifluoroacetyl compound to compound II to obtain compound III;

s3, hydrolyzing the compound III to obtain a compound IV;

wherein the trifluoroacetyl compound is any one of trifluoroacetyl chloride, trifluoroacetyl bromide, trifluoroacetate and trifluoroacetic anhydride, and in the compound I, R is₁，R₂is-Cl, -Br, -F, -CF₃One of (1); r₃Is methyl, trifluoromethyl or tert-butyl; r₃is-H, -Cl, -Br,-one of F; r₄Is any one of fluorine, chlorine, bromine, iodine, hydroxyl and hydrogen.

In the above technical scheme, firstly, the strong positioning effect of amino is utilized, because R₁And R₂All of which are electron-withdrawing groups, the positioning effect of which is basically covered by the positioning effect of the amino group, so that the acylation reaction in the step S2 is not easy to occur the substitution reaction on other sites, and simultaneously, R₁And R₂The reactivity of the surface of the benzene ring is also inhibited, so that the multi-acylation reaction is not easy to occur, and the electron cloud density on the benzene ring is reduced after acylation, which is also beneficial to reducing or avoiding the multi-acylation reaction. Therefore, the technical solution in the present application has better selectivity in step S2, which also helps to improve the final yield.

After amino is protected, acylation reaction is carried out, deprotection is carried out, the whole reaction flow is simple, the process is not complex, the conditions are mild, the yield is high, and the method is suitable for industrial large-scale production.

Optionally, in step S1, the acylation protection reagent is acetic anhydride, and the amount of the substance of the acylation protection reagent is 1 to 1.5 times of the amount of the substance of the compound i.

The acetic anhydride has mild reaction conditions, and after the amino group is protected, the influence on the reaction performance of the benzene ring is small, thereby being beneficial to improving the yield of the reaction on the whole.

Optionally, in step S2, trifluoroacetyl compound is trifluoroacetyl chloride.

The method has the advantages that the method adopts trifluoroacetyl chloride, has better yield, simultaneously has stronger reaction activity of trifluoroacetyl chloride, so the required reaction time is shorter, and redundant acetyl chloride and generated byproducts have better solubility in water and can be removed by washing, thereby being beneficial to simplifying the process.

Optionally, in step S2, the lewis acid is aluminum chloride or zinc chloride.

Aluminum chloride and zinc chloride are weak acids, are weak in corrosivity, have small pressure on equipment, are easy to remove redundant Lewis acid through water washing, and have a good effect on industrial production.

Optionally, step S2 is performed in a solvent system immiscible with water, and after the reaction is finished, the system obtained in step S1 is washed with an aqueous solution of a base i to a pH greater than 6.4, and the aqueous phase is removed to leave an organic phase.

In the above technical solution, the alkali washing contributes to further improving the solubility of the by-product in water, reducing the solubility of the by-product in the organic phase, and improving the separation effect in step S2.

Optionally, in step S2, the mass ratio of the compound II, the Lewis acid and the trifluoroacetyl compound is 1: (2-5).

The reaction is carried out according to the proportion, so that the compound II has better conversion rate and is beneficial to reducing the cost in industry.

Optionally, in step S3, hydrolyzing by catalysis of alkali ii, wherein alkali ii is sodium hydroxide or potassium hydroxide; in step S3, compound iii is added to an aqueous solution of base ii with a mass fraction of 5 to 20% to react.

In the technical scheme, the hydrolysis is carried out by using a sodium hydroxide or potassium hydroxide system, the reaction is fast, and impurities are easy to remove by simple extraction, which is beneficial to simplifying the operation flow in industrial production. The reaction is carried out through an aqueous solution system of alkali II, and the target product can be purified by directly carrying out oil-water separation after the reaction is finished, so that the overall process is simpler.

Optionally, the mass ratio of the alkali II to the compound III is (1-1.5) to 1.

In the technical scheme, the dosage of the alkali II is slightly higher than that of the compound III, so that the compound III can fully react, and the reaction rate is high.

In addition, the application also provides a preparation method of the 3, 5-substituted-4-amino trifluoro acetophenone derivative, the 3, 5-substituted-4-amino trifluoro acetophenone derivative is prepared by the preparation method, diazotization is carried out on amino, and the amino is substituted by any one of hydrogen, hydroxyl, fluorine, chlorine and bromine.

The method has the advantages of simple and easily-obtained raw material sources, simple process flow, mild conditions and good industrial production application prospect.

In summary, the present application includes at least one of the following advantages:

1. in the application, 3, 5-substituted-4-amino trifluoro acetophenone is obtained by three steps of amino protection, acylation reaction and amino deprotection of an ortho-disubstituted aniline compound, and the reaction has high yield and a simpler reaction process and is suitable for industrial production.

2. In a further arrangement of the present application, the same solvent may be used for the reaction in step S1 and step S2, without separate isolation, which helps to further simplify the process flow of the reaction.

Detailed Description

The present application will be described in further detail with reference to examples.

Example 1

A preparation method of 3, 5-substituted-4-amino trifluoro acetophenone is used for preparing 3, 5-dichloro-4-amino trifluoro acetophenone, and the reaction is shown as formula I-1.

Wherein R is₃Is methyl.

The method comprises the following specific steps:

s1, weighing 0.2mol (32.40g) of compound I and 0.21mol (21.44g) of acetic anhydride (namely, acylation protecting reagent) and dissolving in 100mL of ethyl acetate, heating to 70 +/-5 ℃, refluxing and stirring, reacting for 0.5h, basically completing the reaction, decompressing and concentrating the ethyl acetate to 10mL, recovering the ethyl acetate, then pouring into 200mL of ice water at 5 ℃, filtering and retaining filter residues, and drying to obtain a white solid compound, namely compound II. The NMR data of compound II are as follows: 1H NMR (400MHz, CDCl3) d 7.40(d,2H),7.20(t,1H),6.90(br,1H),2.26(s, 3H).

S2, weighing 0.25mol (33.12g) of trifluoroacetyl chloride (namely trifluoroacetyl compound) and 0.30mol (40.00g) of anhydrous aluminum chloride (namely Lewis acid), adding the weighed materials into 100mL of trichloromethane, stirring the materials at the temperature of minus 20 +/-5 ℃ until the materials are completely dissolved, then uniformly adding 0.1mol (20.41g) of compound II into the solution within 4h, controlling the temperature to be lower than 0 ℃ in the adding process, fully reacting after the dropwise adding is finished, monitoring a point board to find that the required reaction time is 2h, adding the reaction liquid into 300mL of 5 ℃ ice water after the reaction is finished, standing and layering, reserving an organic phase, washing the organic phase with saturated sodium bicarbonate solution until the pH value is higher than 6.4, then drying the organic phase with anhydrous sodium sulfate, concentrating the organic phase under reduced pressure and drying the dried organic phase to obtain a white solid with slight yellow color, namely the compound III.

S3, weighing 0.2mol (60.01g) of the compound III, adding the compound III into 100mL of a 10% sodium hydroxide aqueous solution (containing 0.25mol of sodium hydroxide), heating to 50 +/-10 ℃, stirring, keeping the temperature until the mixture is sufficiently hydrolyzed, carrying out hydrolysis for 4 hours, stopping stirring after the reaction is finished, cooling to 0 +/-5 ℃, separating to remove excessive moisture, and carrying out reduced pressure distillation to obtain a yellow oily liquid, namely the compound IV. The nuclear magnetic resonance hydrogen spectrum data of the compound IV are as follows: 1H NMR (400MHz in CDCl 3). delta.5.26, 7.94.

Example 2

The preparation method of the 3, 5-substituted-4-amino trifluoro acetophenone is used for preparing the 3, 5-dibromo-4-amino trifluoro acetophenone, and is different from the preparation method of the example 1 in that the compound I in the raw materials is 2, 6-dibromoaniline, and the specific reaction is shown as a formula I-2.

Example 3

The preparation method of the 3, 5-substituted-4-amino trifluoro acetophenone is used for preparing the 3, 5-difluoro-4-amino trifluoro acetophenone, and is different from the example 1 in that the compound I in the raw material is 2, 6-difluoroaniline, and the specific reaction is shown as a formula I-3.

Example 4

The preparation method of the 3, 5-substituted-4-amino trifluoro acetophenone is used for preparing the 3-chloro-5-fluoro-4-amino trifluoro acetophenone, and is different from the preparation method of the example 1 in that the compound I in the raw material is 2-chloro-6-fluoroaniline, and the specific reaction is shown as a formula I-4.

Example 5

The difference between the preparation method of the 3, 5-substituted-4-amino trifluoro acetophenone and the preparation method of the 3-chloro-5-trifluoromethyl-4-amino trifluoro acetophenone in the embodiment 1 is that the compound I in the raw material is 2-chloro-6-trifluoromethyl aniline, and the specific reaction is shown as a formula I-5.

Example 6

The difference between the preparation method of the 3, 5-substituted-4-amino trifluoro acetophenone and the preparation method of the 3-bromo-5-trifluoromethyl-4-amino trifluoro acetophenone in the embodiment 1 is that the compound I in the raw material is 2-bromo-6-trifluoromethyl aniline, and the specific reaction is shown as a formula I-6.

Example 7

The difference between the preparation method of the 3, 5-substituted-4-amino trifluoro acetophenone and the preparation method of the 3-fluoro-5-trifluoromethyl-4-amino trifluoro acetophenone in the embodiment 1 is that the compound I in the raw material is 2-fluoro-6-trifluoromethylaniline, and the specific reaction is shown as the formula I-6.

In examples 1 to 7, the yield, total yield and final purity of each step are shown in Table 1.

Table 1, yield and purity of each step in examples 1 to 7

From the above experimental data, it can be seen that the 3, 5-disubstituted-5-anilinotrifluoroacetophenone prepared by the scheme of the present application has a high yield, wherein the yield in example 6 is the lowest, probably due to the easy shedding of the bromine substituent during the reaction to generate a by-product. However, in the present application, at least the preparation of 3, 5-dibromo-4-amino-trifluoroacetophenone can be achieved, and several methods in the reference documents have difficulty in obtaining a bromine-substituted product due to its strong substitution reaction activity on the benzene ring.

Example 8

A method for producing 3, 5-substituted-4-aminotrifluorophenone, which is useful for producing 3, 5-dichloro-4-aminotrifluorophenone, is different from example 1 in that the amount of an acylation protecting agent and the like is replaced with trifluoroacetic anhydride.

Example 9

A method for producing 3, 5-substituted-4-aminotrifluorophenone, which is used for producing 3, 5-difluoro-4-aminotrifluorophenone, is different from example 2 in that the amount of an acylation protecting agent and the like is replaced with trifluoroacetic anhydride.

Example 10

A method for producing 3, 5-substituted-4-aminotrifluorophenone, which is useful for producing 3, 5-difluoro-4-aminotrifluorophenone, is different from example 3 in that the amount of an acylation protecting agent and the like is replaced with trifluoroacetic anhydride.

Example 11

A process for producing 3, 5-substituted-4-aminotrifluorophenone, which is useful for producing 3-chloro-5-fluoro-4-aminotrifluorophenone, which is different from example 4 in that the amount of the acylation protecting agent and the like is replaced with trifluoroacetic anhydride.

Example 12

A process for producing 3, 5-substituted-4-aminotrifluorophenone, which is useful for producing 3-chloro-5-trifluoromethyl-4-aminotrifluorophenone, differs from example 5 in that the amount of the acylation protecting agent and the like is replaced with trifluoroacetic anhydride.

Example 13

A method for producing 3, 5-substituted-4-aminotrifluorophenone, which is useful for producing 3-bromo-5-trifluoromethyl-4-aminotrifluorophenone, differs from example 6 in that the amount of the acylation protecting agent and the like is replaced with trifluoroacetic anhydride.

Example 14

A process for producing 3, 5-substituted-4-aminotrifluorophenone, which is useful for producing 3-fluoro-5-trifluoromethyl-4-aminotrifluorophenone, differs from example 7 in that the amount of the acylation protecting agent and the like is replaced with trifluoroacetic anhydride.

The yields and final product purities of the steps in examples 8 to 14 are shown in Table 2.

Table 2, yield and purity of each step in examples 8 to 14

The use of trifluoroacetyl group as the amino-protecting group gives a higher yield in both the protecting and deprotecting steps, but in step S2, S2 gives a lower yield due to the fact that trifluoroacetyl group has too strong electron withdrawing ability and poor selectivity of amide group substitution at the para-position.

Next, based on example 1, the following examples were obtained by further adjusting part of the parameters and the reaction method.

Example 15

A method for preparing 3, 5-substituted-4-aminotrifluorophenone for preparing 3, 5-dichloro-4-aminotrifluorophenone, which differs from example 1 in that the amount of acetic anhydride was 0.2mol, giving a yield of step S1 of 94.2% and a yield of step S2 of 80.9%.

Example 16

A method for preparing 3, 5-substituted-4-aminotrifluorophenone for preparing 3, 5-dichloro-4-aminotrifluorophenone, which differs from example 1 in that the amount of the substance of acetic anhydride was 0.3mol, resulting in a yield of step S1 of 98.0% and a yield of step S2 of 76.7%.

Example 17

A method for preparing 3, 5-substituted-4-aminotrifluorophenone for preparing 3, 5-dichloro-4-aminotrifluorophenone, which is different from example 1 in that the amount of the substance of acetic anhydride was 0.4mol, resulting in a yield of step S1 of 98.1% and a yield of step S2 of 69.5%. The reason why the yield is low in step S2 here may be that, in step S1, since excessive acetic anhydride is used, it is difficult to completely remove acetic anhydride, and therefore, the acylation reaction in step S2 is affected to some extent.

Example 18

A method for producing 3, 5-substituted-4-aminotrifluorophenone, which is for producing 3, 5-dichloro-4-aminotrifluorophenone, differs from example 1 in that trifluoroacetyl compound is trifluoroacetyl bromide in step S2, and the yield in step S2 is 72.0%.

Example 19

The 3, 5-substituted-4-aminotrifluorophenone preparation method, which was used to prepare 3, 5-dichloro-4-aminotrifluorophenone, differs from example 1 in that ethyl trifluoroacetyl compound was used as ethyl trifluoroacetate in step S2, and the yield in step S2 was 68.5%.

Example 20

A method for preparing 3, 5-substituted-4-amino trifluoroacetophenone, for preparing 3, 5-dichloro-4-amino trifluoroacetophenone, differs from example 1 in that lewis acid is zinc chloride anhydrous in an equivalent amount in step S2, and the yield of step S2 is 75.7%.

Example 21

A method for preparing 3, 5-substituted-4-aminotrifluorophenone, for preparing 3, 5-dichloro-4-aminotrifluorophenone, which is different from example 1 in that, in step S2, sulfuric acid in an amount of equivalent substance of lewis acid is added in the form of a 98% aqueous solution. The sulfuric acid is added dropwise, the temperature is controlled to be lower than 0 ℃ during the dropwise addition, the yield of the step S2 is 63.7%, and in the reaction, the yield is obviously lower than that of the reaction taking inorganic salt as Lewis acid.

Examples 22 to 29

A method for preparing 3, 5-substituted-4-aminotrifluoroacetophenone, which is used for preparing 3, 5-dichloro-4-aminotrifluoroacetophenone, is different from example 1 in that, in step S2, lewis acid and trifluoroacetyl compound are used in amounts as specifically shown in table 3.

TABLE 3 amounts of Lewis acid and trifluoroacetyl compound used in examples 22 to 29

Examples 30 to 37

A method for preparing 3, 5-substituted-4-amino trifluoroacetophenone, which is used for preparing 3, 5-dichloro-4-amino trifluoroacetophenone, differs from example 1 in that the selection, amount and concentration of base ii in step S3 are specifically shown in table 4.

Table 4 and Experimental results of examples 30 to 37

In the above examples, in example 31, the reaction time is greatly prolonged and hydrolysis takes 8 to 9 hours completely, as shown by spot plate monitoring, and it is proved that when the concentration of alkali ii is too low, the reaction rate is significantly affected. Similarly, in example 36, the amount of sodium hydroxide used is too small, and although sodium hydroxide only acts as a catalyst, the reaction rate of the system is adversely affected by too small an amount of alkali, and it was found that about 15 hours is required for complete hydrolysis in example 36.

Example 38

A method for preparing 3, 5-substituted-4-amino trifluoroacetophenone, which is used for preparing 3, 5-dichloro-4-amino trifluoroacetophenone, differs from example 1 in that steps S1 and S2 are specifically as follows:

s1, weighing 0.2mol (32.40g) of compound I and 0.21mol (21.44g) of acetic anhydride (namely, acylation protecting reagent) to dissolve in 100mL of dichloromethane, heating to 70 +/-5 ℃, refluxing and stirring, after the reaction is carried out for 0.5h, basically completing the reaction, washing and extracting by using 100mL of water, and retaining an organic phase.

S2, weighing 0.5mol (66.24g) of trifluoroacetyl chloride (namely trifluoroacetyl compound) and 0.60mol (80.00g) of anhydrous aluminum chloride (namely Lewis acid), adding the trifluoroacetyl chloride and the anhydrous aluminum chloride into 100mL of dichloromethane, fully stirring at the temperature of minus 20 +/-5 ℃, then uniformly dropwise adding the organic phase obtained in the step S1 into the solution within 4h, controlling the temperature to be lower than 0 ℃ in the dropwise adding process, fully reacting after the dropwise adding is finished, monitoring a point plate to find that the required reaction time is 2h, adding the reaction solution into 500mL of 5 ℃ ice water after the reaction is finished, standing for layering, retaining the organic phase, washing the organic phase with saturated sodium bicarbonate solution until the pH value is higher than 6.4, then drying the organic phase with anhydrous sodium sulfate, concentrating and drying to obtain a white solid which is slightly yellowish under reduced pressure, namely the compound III.

In this step, the overall yield of step S1 and step S2 was 70.1%, which was slightly lower than 77.3% of example 1.

Example 39

A method for preparing 3, 5-substituted-4-aminotrifluorophenone for preparing 3, 5-dichloro-4-aminotrifluorophenone, which is different from example 37 in that dichloromethane was replaced with an equal volume of chloroform and the total yield of step S1 and step S2 was 69.9%.

Example 40

A method for preparing 3, 5-substituted-4-aminotrifluorophenone, which was used for preparing 3, 5-dichloro-4-aminotrifluorophenone, differs from example 37 in that dichloromethane was replaced with an equal volume of dichloroethane and the total yield of step S1 and step S2 was 65.2%.

The method of combining and reacting the step S1 and the step S2 directly without separation after simple extraction is adopted, the yield is slightly lower than the yield of reaction after separation, but the method is favorable for saving cost industrially, and both the method and the device can realize industrial production.

An amplification experiment was performed for example 1 and example 38, and the results were as follows.

EXAMPLE 41

The preparation method of 3, 5-substituted-4-amino trifluoro acetophenone is used for preparing 3, 5-dichloro-4-amino trifluoro acetophenone, and comprises the following steps:

s1, weighing 3.2kg of 2, 6-dichloroaniline, adding the weighed 2, 6-dichloroaniline into a reaction kettle, adding 10L of ethyl acetate, adding 2.2kg of acetic anhydride, heating to 70 +/-5 ℃, stirring for 30min, then pumping the mixture into a concentration kettle, heating to evaporate ethyl acetate, wherein the ethyl acetate can be recycled, adding ice water when the amount of residual ethyl acetate is less than 1L, cooling the system, wherein the adding amount of the ice water is 10L, then pumping the mixture into a spin filter to perform spin filtration, keeping a filter cake, and drying the filter cake for 30min at 80 ℃ in air to obtain a compound II.

S2, weighing 1.7kg of trifluoroacetyl chloride and 2.0kg of anhydrous aluminum chloride, dissolving the trifluoroacetyl chloride and the anhydrous aluminum chloride in 5L of dichloromethane, cooling the trifluoroacetyl chloride to the temperature of minus 20 +/-5 ℃ through an ethanol refrigerant, uniformly adding 1.0kg of compound II into the solution within 4h, reacting for 3h after the addition is finished, then pumping the obtained product into an extraction tower, adding 10L of deionized water, controlling the temperature of the system to be lower than 10 ℃, standing and layering, extracting the organic phase again by using a saturated ammonium bicarbonate solution until the pH value of the organic phase is higher than 6.4, adsorbing and drying the organic phase by using active carbon, and distilling off the dichloromethane to obtain a light yellow solid, namely the compound III.

S3, preparing 5L of 10% sodium hydroxide solution, weighing 3kg of the compound III in the step S2, adding the compound III into the sodium hydroxide solution, stirring and reacting at 50 +/-10 ℃ for 5 hours, then cooling to 0 +/-5 ℃, pumping the mixture into an extraction tower, adding dichloromethane into the extraction tower for extraction, carrying out vacuum distillation on the organic phase to remove the solvent, and recovering the dichloromethane to obtain yellow oily liquid, namely the compound IV.

Example 42

A method for preparing 3, 5-substituted-4-aminotrifluoroacetophenone, which is used for preparing 3, 5-dichloro-4-aminotrifluoroacetophenone, is different from example 40 in that steps S1 and S2 are specifically as follows:

s1, weighing 3.2kg of 2, 6-dichloroaniline, adding the weighed 2, 6-dichloroaniline into a reaction kettle, adding 10L of dichloromethane and 2.2kg of acetic anhydride, heating to 70 +/-5 ℃, stirring for 30min, then pumping the mixture into a concentration kettle, heating to evaporate ethyl acetate, wherein the ethyl acetate can be recycled, adding ice water and cooling the system when the amount of residual ethyl acetate is less than 1L, wherein the adding amount of the ice water is 10L, and then separating liquid and retaining an organic phase to obtain a mixed system I.

S2, weighing 6.6kg of trifluoroacetyl chloride and 8.0kg of anhydrous aluminum chloride, dissolving the trifluoroacetyl chloride and the anhydrous aluminum chloride in 10L of dichloromethane, cooling the trifluoroacetyl chloride to the temperature of minus 20 +/-5 ℃ through an ethanol refrigerant, uniformly adding the mixed system I into the solution within 4h, reacting for 3h after the addition is finished, then pumping the obtained product into an extraction tower, adding 15L of deionized water, controlling the temperature of the system to be lower than 10 ℃, standing and layering, extracting the organic phase again by using a saturated ammonium bicarbonate solution until the pH value of the organic phase is higher than 6.4, adsorbing and drying the organic phase by using active carbon, and evaporating dichloromethane to obtain a light yellow solid, namely the compound III.

The yields of the respective steps of example 41 and example 42 are shown in table 5.

Table 5, the yield and purity of each step in examples 41 to 42

According to the embodiments, the two methods in the application can achieve better preparation effects.

On the basis of the above examples, the following examples were obtained by further subjecting the compound IV obtained to an amino substitution reaction:

example 43-1

The preparation method of the 3, 5-substituted-4-amino trifluoro acetophenone derivative is used for preparing the 3, 5-dichloro-trifluoro acetophenone, and the preparation method comprises the following steps:

weighing 0.3mol (77.4g) of 3, 5-dichloro-4-amino trifluoro acetophenone, dissolving in 300mL of toluene, heating to 50 ℃ to dissolve the 3, 5-dichloro-4-amino trifluoro acetophenone, then cooling to a temperature lower than 0 ℃, dropwise adding 125g of sulfuric acid with the mass fraction of 25% for acidification, keeping the temperature lower than 0 ℃ in the acidification process, dropwise adding for 1h, continuing to perform heat preservation reaction for 1h after acidification is finished, then uniformly dropwise adding 138.0g of sodium nitrite aqueous solution with the mass fraction of 33% (containing 0.66mol of diazotization reagent sodium nitrite) in 1.5h, continuing to perform reaction for 2h at the temperature lower than 0 ℃, naturally heating to room temperature, adding 131g of hypochlorous acid with the mass fraction of 50% and 0.8g of cuprous oxide, continuing to perform reaction for 2h at room temperature, standing for layering after the reaction is finished, and cleaning an organic layer by using 50mL of sodium bicarbonate aqueous solution with the mass fraction of 5%, anhydrous magnesium sulfate is dried and rectified to obtain clear and transparent oily to light yellow liquid. The reaction yield was 86.2% and the purity was 99.6%. The nmr spectrum of the final product is as follows: 1H NMR (400MHz, CDCl3)7.95(s,2H),5.23(bs, 2H).

Example 43-2

A preparation method of 3, 5-substituted-4-amino trifluoro acetophenone derivatives is used for preparing 3-chloro-5-trifluoromethyl acetophenone.

The difference from example 43-1 was that the amount of 3, 5-dichloro-4-aminotrifluoroacetophenone and the like was changed to 3-chloro-5-trifluoromethyl-4-aminotrifluoroacetophenone, resulting in a reaction yield of 84.2% and a purity of 99.5%.

Examples 43 to 3

A preparation method of 3, 5-substituted-4-amino trifluoro acetophenone derivatives is used for preparing 3-bromo-5-trifluoromethyl acetophenone.

The difference from example 43-1 was that the amount of 3, 5-dichloro-4-aminotrifluoroacetophenone and the like was changed to 3-bromo-5-trifluoromethyl-4-aminotrifluoroacetophenone, resulting in a reaction yield of 83.8% and a purity of 99.8%.

Examples 43 to 4

A preparation method of 3, 5-substituted-4-amino trifluoro acetophenone derivatives is used for preparing 3-fluoro-5-trifluoromethyl acetophenone.

The difference from example 43-1 was that the amount of 3, 5-dichloro-4-aminotrifluoroacetophenone and the like was replaced with 3-fluoro-5-trifluoromethyl-4-aminotrifluoroacetophenone, which was obtained in a reaction yield of 85.2% and a purity of 99.5%.

Example 44-1

The preparation method of the 3, 5-substituted-4-amino trifluoro acetophenone derivative is used for preparing the 3,4, 5-trichloro trifluoro acetophenone, and comprises the following specific steps:

weighing 0.2mol (51.6g) of 3, 5-dichloro-4-amino trifluoro acetophenone, dissolving the 3, 5-dichloro-4-amino trifluoro acetophenone in 300mL of hydrochloric acid with the mass fraction of 37%, heating the solution to 60 ℃, cooling the solution to-10 to 0 ℃ after the system is clarified, uniformly dropwise adding 50.3g (containing 0.24mol of sodium nitrite) of sodium nitrite solution with the mass fraction of 33% in 1h, controlling the temperature of the system to be lower than 0 ℃, and continuously stirring the solution for 0.5h after the dropwise adding is finished to obtain the diazonium solution.

And adding 29.7g (0.3mol) of cuprous chloride into 300mL of hydrochloric acid with the mass fraction of 37%, stirring at 60 ℃ for 1h to uniformly mix, uniformly dropwise adding the prepared diazo liquid into the system within 1h, keeping the temperature and stirring for reacting for 1h after dropwise adding is finished, naturally cooling to the normal temperature, extracting with 300mL of dichloromethane, and repeating for three times. The organic phases were combined, dried over anhydrous magnesium sulfate and the solvent was distilled under reduced pressure to give a pale yellow oily liquid with a final product yield of 89.7% and a purity of 99.3%. The nmr hydrogen spectra of the final product were as follows: 1H NMR (400MHz, CDCl3)8.05(d, J ═ 0.8Hz, 2H).

Example 44-2

A preparation method of 3, 5-substituted-4-amino trifluoro acetophenone derivatives is used for preparing 3,4, dichloro-5-trifluoromethyl acetophenone.

The difference from example 44-1 was that the amount of 3, 5-dichloro-4-aminotrifluoroacetophenone and the like was changed to 3-chloro-5-trifluoromethyl-4-aminotrifluoroacetophenone, which was obtained in a reaction yield of 86.4% and a purity of 99.7%.

Examples 44 to 3

A preparation method of 3, 5-substituted-4-amino trifluoro acetophenone derivatives is used for preparing 3-bromo-4-chloro-5-trifluoromethyl acetophenone.

The difference from example 44-1 was that the amount of 3, 5-dichloro-4-aminotrifluoroacetophenone and the like was changed to 3-bromo-5-trifluoromethyl-4-aminotrifluoroacetophenone, resulting in a reaction yield of 81.1% and a purity of 99.1%.

Examples 44 to 4

A preparation method of 3, 5-substituted-4-amino trifluoro acetophenone derivatives is used for preparing 3-fluoro-4-chloro-5-trifluoromethyl acetophenone.

The difference from example 44-1 was that the amount of 3, 5-dichloro-4-aminotrifluoroacetophenone and the like was changed to 3-fluoro-5-trifluoromethyl-4-aminotrifluoroacetophenone, resulting in a reaction yield of 83.8% and a purity of 99.4%.

Example 45-1

A preparation method of a 3, 5-substituted-4-amino trifluoro acetophenone derivative is used for preparing 3, 5-dichloro-4-bromo-trifluoro acetophenone, and comprises the following specific steps:

weighing 0.2mol (51.6g) of 3, 5-dichloro-4-amino trifluoro acetophenone, dissolving in 300mL of acetonitrile, heating to 50 ℃, keeping stirring, adding 300mL of hydrobromic acid with the mass fraction of 47%, keeping the temperature and stirring for 1h to obtain uniform suspension, cooling to-5 +/-5 ℃, uniformly dropwise adding 50.3g (containing 0.24mol of diazotization reagent sodium nitrite) of sodium nitrite solution with the content of 33% in 1h, controlling the system temperature to be lower than 0 ℃ in the dropwise adding process, after the dropwise adding is finished, continuously controlling the temperature to be below 0 ℃ and stirring for 0.5h, then uniformly adding 43.0g (0.3mol) of cuprous bromide in 30min, heating to 60 ℃ after the dropwise adding is finished, and stirring for 1 h. After the reaction is finished, the temperature is reduced to normal temperature, the mixture is extracted by 300mL of dichloromethane, and the process is repeated for three times. The organic phases were combined, dried over anhydrous magnesium sulfate, and the solvent was distilled under reduced pressure to give a pale yellow oily liquid, i.e., 3, 5-dichloro-4-bromo-trifluoroacetophenone, in a yield of 79.0% and a purity of 99.4%.

Example 45-2

A preparation method of 3, 5-substituted-4-amino trifluoro acetophenone derivatives is used for preparing 3-chloro-4-bromo-5-trifluoromethyl acetophenone.

The difference from example 45-1 was that the amount of 3, 5-dichloro-4-aminotrifluoroacetophenone and the like was replaced with 3-chloro-5-trifluoromethyl-4-aminotrifluoroacetophenone, which was obtained in a reaction yield of 74.3% and a purity of 99.2%.

Examples 45 to 3

A preparation method of a 3, 5-substituted-4-amino trifluoro acetophenone derivative is used for preparing 3, 4-dibromo-5-trifluoromethyl trifluoro acetophenone.

The difference from example 45-1 was that the amount of 3, 5-dichloro-4-aminotrifluoroacetophenone and the like was replaced with 3-bromo-5-trifluoromethyl-4-aminotrifluoroacetophenone, which was obtained in 69.6% yield and 99.1% purity.

Examples 45 to 4

A preparation method of 3, 5-substituted-4-amino trifluoro acetophenone derivatives is used for preparing 3-fluoro-4-bromo-5-trifluoromethyl acetophenone.

The difference from example 45-1 was that the amount of 3, 5-dichloro-4-aminotrifluoroacetophenone and the like was replaced with 3-fluoro-5-trifluoromethyl-4-aminotrifluoroacetophenone, which was obtained in a reaction yield of 73.4% and a purity of 99.0%.

Example 46-1

The preparation method of the 3, 5-substituted-4-amino trifluoro acetophenone derivative is used for preparing the 3, 5-dichloro-4-fluoro acetophenone, and comprises the following specific steps:

weighing 0.2mol (51.6g) of 3, 5-dichloro-4-amino trifluoro acetophenone, adding the weighed 0.2mol (51.6g) into 300mL of hydrogen fluoride pyridine solution which is cooled to 0 +/-5 ℃ in 30min in batches, keeping the mass fraction of hydrogen fluoride in the hydrogen fluoride pyridine solution at 0 +/-5 ℃, stirring for 1h, uniformly dropwise adding 50.3g (containing 0.24mol of nitrous acid reagent sodium nitrite) of sodium nitrite solution with the mass fraction of 33% in 1h, controlling the temperature of the system to be lower than 0 ℃, continuing stirring for 30min under heat preservation after dropwise adding, then heating to 60 ℃, stirring and reacting for 3h, naturally cooling to normal temperature after the reaction is finished, quenching the system by using 100mL of water and diethyl ether with the volume ratio of 1: 1, and separating an organic layer after the quenching is finished. Washing the organic layer with 300mL of saturated sodium chloride solution, then carrying out reduced pressure concentration on the organic layer, eluting with 200mL of toluene, and drying to obtain yellow clear transparent liquid, namely the target product, wherein the yield is 81.7%, and the purity is 99.3%.

Example 46-2

A preparation method of 3, 5-substituted-4-amino trifluoro acetophenone derivatives is used for preparing 3-chloro-4-fluoro-5-trifluoromethyl acetophenone.

The difference from example 46-1 was that the amount of 3, 5-dichloro-4-aminotrifluoroacetophenone and the like was changed to 3-chloro-5-trifluoromethyl-4-aminotrifluoroacetophenone, which was obtained in a reaction yield of 78.3% and a purity of 99.2%.

Examples 46 to 3

A preparation method of 3, 5-substituted-4-amino trifluoro acetophenone derivatives is used for preparing 3-bromo-4-fluoro-5-trifluoromethyl acetophenone.

The difference from example 46-1 was that the amount of 3, 5-dichloro-4-aminotrifluoroacetophenone and the like was changed to 3-bromo-5-trifluoromethyl-4-aminotrifluoroacetophenone, resulting in a reaction yield of 68.8% and a purity of 99.2%.

Examples 46 to 4

A preparation method of 3, 5-substituted-4-amino trifluoro acetophenone derivatives is used for preparing 3, 4-difluoro-5-trifluoromethyl acetophenone.

The difference from example 46-1 was that the amount of 3, 5-dichloro-4-aminotrifluoroacetophenone and the like was replaced with 3-fluoro-5-trifluoromethyl-4-aminotrifluoroacetophenone, which was obtained in a reaction yield of 76.4% and a purity of 99.5%.

According to the embodiment, the technical scheme further modifies the 3, 5-dichloro-4-amino trifluoro acetophenone to obtain different drug intermediates, and the application prospect is good.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.