Preparation method of triazine compound

Abstract

The invention relates to a preparation method of a triazine compound, which comprises the following steps: in a gas atmosphere containing carbon dioxide, carrying out etherification reaction on a triazine intermediate and halogenated alkane to prepare the triazine compound, wherein the structure of the triazine intermediate is as shown in a formula I, and the structure of the triazine compound is as shown in a formula II. According to the preparation method of the triazine compound provided by one embodiment of the invention, the etherification reaction of the triazine intermediate and the halogenated alkane is carried out in the atmosphere of the gas containing the carbon dioxide, so that the selectivity of the reaction can be improved, and the yield of the product is further improved. # imgabs0 #

Description

Technical Field

[0001] The invention relates to triazine compounds, and in particular to a method for preparing triazine compounds capable of improving reaction selectivity. Background Art

[0002] Triazine ultraviolet absorbers include UV-460, UV-470, PC-S, etc. The existing etherification reaction for preparing triazine compounds is basically carried out in amide solvents such as DMF or aromatic hydrocarbon solvents such as toluene. There are problems with reaction selectivity when carrying out reactions in these solvents.

[0003]

[0004] In order to control the reaction selectivity in the existing process, the material molar ratio is basically adjusted or a mixed solvent is used, but the actual effect is poor, and the proportion of the mixed solvent recovered during the production process will change, and the subsequent use of the recovered solvent needs to be adjusted again; at the same time, since the solvent used for synthesizing triazine intermediates is often chlorobenzene or sulfone solvents, there is a problem of inconsistency between the previous and subsequent solvents, resulting in the intermediates needing to be dried before use, which increases the process. Summary of the invention

[0005] In order to overcome at least one defect of the above-mentioned prior art, in a first aspect, an embodiment of the present invention provides a method for preparing a triazine compound, comprising: in an atmosphere containing a gas of carbon dioxide, subjecting a triazine intermediate to an etherification reaction with a halogenated alkane to obtain a triazine compound; wherein the structure of the triazine intermediate is as shown in Formula I, and the structure of the triazine compound is as shown in Formula II;

[0006]

[0007] Among them, R 1 , R 3 , R 4 , R 6 , R 7 , R 9 are each independently selected from a hydroxyl group, a methyl group, a methoxy group or a hydrogen atom, and R 1 , R 3 , R 4 , R 6 , R 7 , R 9 At least two of them are hydroxyl groups, R 2 , R 5 , R 8 Each is independently selected from a methyl group or a hydrogen atom;

[0008] E 1 、E 2 、E3 、E 4 、E 5 、E 6 are each independently selected from a hydroxyl group, a methyl group, an alkoxy group containing 1 to 24 carbon atoms, or a hydrogen atom, and E 1 、E 2 、E 3 、E 4 、E 5 、E 6 At least one of the groups is an alkoxy group having 1 to 24 carbon atoms.

[0009] In a method for preparing triazine compounds according to an embodiment of the present invention, the etherification reaction of a triazine intermediate with a halogenated alkane is carried out in an atmosphere containing a gas of carbon dioxide, thereby improving the selectivity of the reaction and further improving the yield of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings are only used to illustrate specific embodiments and are not to be considered as limiting the present invention.

[0011] Figure 1 , 2 The HPLC spectrum and result diagram of the mixed solution after the reaction of Example 3 of the present invention;

[0012] Figure 3 , 4 The HPLC spectrum and result diagram of the mixed solution after the reaction in Comparative Example 1. DETAILED DESCRIPTION

[0013] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions therein are essentially used as illustrations rather than to limit the present invention.

[0014] An embodiment of the present invention provides a method for preparing a triazine compound, comprising: in an atmosphere containing a gas of carbon dioxide, subjecting a triazine intermediate to an etherification reaction with a halogenated alkane to obtain a triazine compound; wherein the structure of the triazine intermediate is as shown in Formula I, and the structure of the triazine compound is as shown in Formula II;

[0015]

[0016] Among them, R 1 , R 3 , R 4 , R 6 , R 7 , R 9 are each independently selected from a hydroxyl group, a methyl group, a methoxy group or a hydrogen atom, and R 1, R 3 , R 4 , R 6 , R 7 , R 9 At least two of them are hydroxyl groups, R 2 , R 5 , R 8 Each is independently selected from a methyl group or a hydrogen atom;

[0017] E 1 、E 2 、E 3 、E 4 、E 5 、E 6 are each independently selected from a hydroxyl group, a methyl group, an alkoxy group containing 1 to 24 carbon atoms or a hydrogen atom, and E 1 、E 2 、E 3 、E 4 、E 5 、E 6 At least one of the groups is an alkoxy group having 1 to 24 carbon atoms.

[0018] In one embodiment, the mass content of carbon dioxide in the gas containing carbon dioxide can be 60-100%, for example 65%, 70%, 75%, 80%, 85%, 88%, 90%, 92%, 95%, 96%, 98%, 99%.

[0019] In one embodiment, during the etherification reaction, a gas containing carbon dioxide is continuously introduced into the system so that the reaction is carried out in an atmosphere of a gas containing carbon dioxide. The flow rate of the gas containing carbon dioxide may be 0.1 to 10 mL / min, and may further be 0.1 to 2 mL / min, such as 0.2 mL / min, 0.3 mL / min, 0.4 mL / min, 0.5 mL / min, 0.6 mL / min, 1 mL / min, 1.2 mL / min, 1.5 mL / min, 1.8 mL / min, 2.5 mL / min, 3 mL / min, 5 mL / min, 8 mL / min.

[0020] In one embodiment, the halogenated alkane contains 1 to 24 carbon atoms, and can further contain 4 to 10 carbon atoms. For example, the number of carbon atoms contained in the halogenated alkane can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 or 24.

[0021] In one embodiment, the halogenated alkane may be a straight chain alkane or an alkane containing a branched chain.

[0022] In one embodiment, the halogenated alkane may be a brominated alkane and / or a chlorinated alkane.

[0023] In one embodiment, the halogenated alkane may be a halogenated octane, a halogenated hexane or a halogenated butane, such as hexyl bromide, isooctane chloride.

[0024] In one embodiment, the triazine intermediate may be an existing compound, or may be prepared by an existing method.

[0025] In one embodiment, the molar ratio of the triazine intermediate to the halogenated alkane can be 1.0:(1.0-10.0), for example, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9.

[0026] In one embodiment, the triazine intermediate is subjected to an etherification reaction with a halogenated alkane in the presence of a phase transfer agent.

[0027] In one embodiment, the phase transfer agent includes one or more of benzyltriethylammonium chloride (TEBA), tetrabutylammonium bromide (TBAB), tetrabutylammonium chloride, and tetrabutylammonium hydrogen sulfate.

[0028] In one embodiment, the mass of the phase transfer agent can be 0.1% to 10% of the mass of the triazine intermediate; further, the mass of the phase transfer agent can be 0.5% to 2% of the mass of the triazine intermediate, for example, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2.2%, 2.5%, 5%, 8%.

[0029] In one embodiment, the reaction system of the triazine intermediate and the halogenated alkane comprises a solvent, and the solvent comprises one or more of N,N-dimethylformamide (DMF) and a sulfone solvent.

[0030] In one embodiment, the solvent in the reaction system of the triazine intermediate and the halogenated alkane is a sulfone solvent, and the sulfone solvent may include one or more of cyclopentane sulfone, diethyl sulfone, and diphenyl sulfone.

[0031] In one embodiment, the mass of the solvent is 2 to 10 times, such as 2.5 times, 3 times, 5 times, 6 times, 8 times, or 9 times, the mass of the triazine intermediate.

[0032] In one embodiment, the reaction system includes a catalyst, and the catalyst may be an inorganic alkaline compound, such as one or more of potassium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide.

[0033] In one embodiment, the molar ratio of the intermediate to the inorganic basic compound can be 1.0:(0.5-7.0), for example 1:1, 1:2, 1:3, 1:4, 1:5, 1:6.

[0034] In one embodiment, the temperature of the etherification reaction of the triazine intermediate and the halogenated alkane can be 60-150°C, and further can be 80-120°C, for example, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 130°C.

[0035] In one embodiment, the reaction endpoint is controlled by real-time sampling and analysis of the mixed solution of the etherification reaction.

[0036] In one embodiment, the mixed solution after the etherification reaction is completed is filtered and subjected to a cooling and crystallization treatment to obtain a triazine compound.

[0037] In one embodiment, the crystallization is performed by cooling with a mixed solvent, and the mixed solvent includes a sulfone solvent and an alcohol solvent.

[0038] In one embodiment, the sulfone solvent used for crystallization can be one or more of cyclopentane sulfone, diethyl sulfone, and diphenyl sulfone; the alcohol solvent can be one or more of methanol, ethanol, propanol, butanol, pentanol, and sec-butanol, and can further be one or more of methanol, ethanol, and propanol.

[0039] In one embodiment, in the mixed solvent used for crystallization, the volume ratio of the sulfone solvent to the alcohol solvent may be 1:(0.5-2.0), and further may be 1:(0.5-1.0).

[0040] In one embodiment, in the triazine intermediate structure shown in Formula I, R 1 , R 3 , R 4 , R 6 , R 7 , R 9 2 to 6 of the groups are hydroxyl groups, for example, two, three, four, five or six of the groups are hydroxyl groups.

[0041] In one embodiment, in the triazine intermediate structure shown in Formula I, R 4 is methoxy, R 1 , R 3 , R 6 , R 7 , R 9 At least two of them are hydroxyl groups; or, R 4 is hydroxyl group, R 1 , R 3 , R 6 , R 7 , R 9 At least one of them is a hydroxyl group.

[0042] In one embodiment, in the triazine intermediate structure shown in Formula I, R 2 , R 5 , R 8 One or both of the groups are methyl, or R 2 , R 5 , R 8 One or both of the groups are hydrogen.

[0043] In one embodiment, in the triazine intermediate structure shown in Formula I, each benzene ring contains two hydroxyl groups or no hydroxyl group.

[0044] In one embodiment, in the triazine compound represented by formula II, E 1 、E 2 、E 3 、E 4 、E 5 、E 6 One, two, three or four of the groups are alkoxy groups containing 1 to 24 carbon atoms. Furthermore, the number of carbon atoms contained in the alkoxy group can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 or 24.

[0045] In one embodiment, in the triazine compound represented by formula II, E 1 、E 2 、E 3 、E 4 、E 5 、E 6 1 to 4 of the groups are alkoxy groups having 1 to 10 carbon atoms.

[0046] In one embodiment, in the triazine compound represented by formula II, E 1 、E 2 、E 3 、E 4 、E 5 、E 6 At least one of them is an alkoxy group containing 1 to 24 carbon atoms, and at least one is a hydroxyl group, that is, the triazine compound contains at least one hydroxyl group and one alkoxy group.

[0047] In one embodiment, in the triazine compound represented by formula II, R 2 , R 5 , R 8 One or both of the groups are methyl, or R 2 , R 5 , R 8 One or both of the groups are hydrogen.

[0048] In one embodiment, in the triazine compound represented by formula II, each benzene ring contains one or two hydroxyl groups or no hydroxyl group. 3 is a methoxy group or an alkoxy group containing 4 to 10 carbon atoms, E 4 is hydroxyl group, E 1 、E 2 、E 5 、E 6 Each is independently selected from hydroxyl and alkoxy groups having 4 to 10 carbon atoms.

[0049] In one embodiment, the triazine intermediate is selected from one or two of the following compounds:

[0050]

[0051] In one embodiment, the triazine compound includes one or more of the following compounds:

[0052]

[0053]

[0054] The preparation method of triazine compounds according to one embodiment of the present invention can improve the selectivity of the reaction and thus improve the yield of the product by performing the etherification reaction of the triazine intermediate and the halogenated alkane in an atmosphere containing a gas of carbon dioxide. In addition, compared with the DMF solvent, the etherification reaction is carried out in a sulfone solvent, and the product has better selectivity, and the use of a sulfone solvent as a reaction solvent can keep the synthesis solvent of the triazine intermediate consistent with the solvent of the etherification reaction, thereby eliminating the need to dry the intermediate and simplifying the production process.

[0055] In one embodiment of the present invention, a method for preparing triazine compounds uses a mixed solvent of a sulfone solvent and an alcohol solvent for cooling crystallization, so that the material is precipitated more completely, the precipitation morphology is good, and the separation speed is fast. During the process, the low-boiling point alcohol solvent will replace the high-boiling point sulfone solvent, so that the material is easy to dry.

[0056] The following is a further description of the preparation method of the triazine compound according to one embodiment of the present invention in conjunction with examples. The raw materials and test methods involved in each example and comparative example are as follows.

[0057] raw material

[0058] The intermediates of formula I-1 and formula I-2 are prepared by reacting cyanuric chloride and corresponding aromatic hydrocarbons in the presence of aluminum chloride catalyst. For details, please refer to the method in patent application CN111892548A.

[0059] Example 1

[0060]

[0061] Add 20.0 g of the intermediate of formula Ⅰ-1, 50 g of cyclopentane, 6.8 g of potassium carbonate, and 37 g of bromohexane into the reactor; introduce carbon dioxide into the reactor at a flow rate of 0.2 mL / min, raise the temperature to 100-105°C, and keep the reaction warm for 5 hours.

[0062] The mixed solution after the reaction was sampled and measured by HPLC to find that the content of the intermediate of formula Ⅰ-1 was 0.5%, the content of the product of formula Ⅱ-1 (trisubstituted product) was 98.21%, and the content of the tetrasubstituted product was 0.2%.

[0063] The mixed solution after the reaction was filtered and desalted, 10 ml of methanol was added to the filtrate, and the temperature was lowered to 40-50°C, and the crystals were precipitated by keeping the temperature. After a large amount of crystals were precipitated, the temperature was lowered to 10-15°C and filtered. The filter cake was washed with methanol and dried to obtain 30.69 g of the final product, with a yield of 98.0% and a purity of 99.15%.

[0064] Example 2

[0065]

[0066] Add 20.0 g of the intermediate of formula Ⅰ-1, 40 g of diethyl sulfone, 4.9 g of sodium carbonate, and 51.7 g of bromohexane into the reactor; introduce carbon dioxide into the reactor at a flow rate of 0.5 mL / min, raise the temperature to 95-100°C, and keep the reaction for 5 hours.

[0067] The mixed solution after the reaction was sampled and measured by HPLC to find that the content of the intermediate of formula Ⅰ-1 was 0.2%, the content of the product of formula Ⅱ-1 (trisubstituted product) was 98.91%, and the content of the tetrasubstituted product was 0.1%.

[0068] The mixed solution after the reaction was filtered to remove salt, 20 ml of ethanol was added to the filtrate, and the temperature was lowered to 30-35°C, and the crystals were precipitated by keeping the temperature. After a large amount of crystals were precipitated, the temperature was lowered to 10-15°C and filtered. The filter cake was washed with ethanol and dried to obtain 30.83 g of the final product, with a yield of 98.45% and a purity of 99.35%.

[0069] Example 3

[0070]

[0071] Add 30.0 g of the intermediate of formula Ⅰ-2, 250 g of diphenyl sulfone, 20.56 g of potassium carbonate, and 148.7 g of isooctane chloride into the reactor; introduce carbon dioxide into the reactor at a flow rate of 0.5 mL / min, raise the temperature to 95-100°C, and keep the reaction warm for 6 hours.

[0072] The mixed solution after the reaction was sampled and measured by HPLC. The content of the intermediate of formula Ⅰ-2 was 0.16%, the content of the product of formula Ⅱ-3 (disubstituted product) was 97.03%, and the content of the trisubstituted product was 0.87%.

[0073] The mixed solution after the reaction was filtered and desalted, 100 ml of methanol was added to the filtrate, and the temperature was lowered to 20-25° C., and the crystals were precipitated at this temperature. After a large amount of crystals were precipitated, the temperature was lowered to 5-10° C. and filtered. The filter cake was washed with methanol and dried to obtain 45.24 g of the final product, with a yield of 96.89% and a purity of 99.76%.

[0074] Example 4

[0075]

[0076] Add 20.0 g of the intermediate of formula Ⅰ-1, 40 g of DMF, 4.9 g of sodium carbonate, and 51.7 g of bromohexane into the reactor; introduce carbon dioxide into the reactor at a flow rate of 0.5 mL / min, raise the temperature to 90-100° C., and keep the reaction for 4 hours.

[0077] The mixed solution after the reaction was sampled and measured by HPLC to find that the content of the intermediate of formula Ⅰ-1 was 0.2%, the content of the disubstituted product was 1.33%, the content of the product of formula Ⅱ-1 was 85.03%, and the content of the tetrasubstituted product was 11.21%.

[0078] The mixed solution after the reaction was filtered to remove salt, 20 ml of ethanol was added to the filtrate, the temperature was lowered to 30-35°C, and the crystals were precipitated by keeping warm. After a large amount of crystals were precipitated, the temperature was lowered to 10-15°C and filtered. The filter cake was washed with ethanol and dried to obtain 27.89 g of the final product, with a yield of 89.06% and a purity of 89.67%.

[0079] Comparative Example 1

[0080]

[0081]

[0082] Add 30.0 g of the intermediate of formula Ⅰ-2, 250 g of diphenyl sulfone, 20.56 g of potassium carbonate, and 148.7 g of isooctane chloride into the reactor, raise the temperature to 95-100°C, and keep the temperature for reaction for 4 hours.

[0083] The mixed solution after the reaction was sampled and measured by HPLC to find that the content of the intermediate of formula Ⅰ-2 was 0.51%, the content of the monosubstituted product was 4.22%, the content of the product of formula Ⅱ-3 (disubstituted product) was 80.64%, and the content of the trisubstituted product was 12.88%.

[0084] The mixed solution after the reaction was filtered and desalted, 100 ml of methanol was added to the filtrate, and the temperature was lowered to 18-20° C., and the crystals were precipitated by keeping the temperature. After a large amount of crystals were precipitated, the temperature was lowered to 5-10° C. and filtered. The filter cake was washed with methanol and dried to obtain 36.52 g of the final product, with a yield of 78.21% and a purity of 91.33%.

[0085] Referring to the description of Example 3 and Comparative Example 1, it can be seen that the difference between the two is mainly that carbon dioxide gas is not introduced into the system during the reaction in Comparative Example 1. The yield of the product of formula II-3 in Example 3 is 98.33%, and the yield of the product of formula II-3 in Comparative Example 1 is 78.21%. By comparison, it can be seen that the yield of the product in Example 3 is much higher than that in Comparative Example 1. And the product yields of Examples 1 and 2, in which the etherification reaction is also carried out in a carbon dioxide gas atmosphere, are both maintained at more than 89%. Therefore, by carrying out the etherification reaction of the triazine intermediate in a carbon dioxide gas atmosphere, the selectivity of the product can be improved, thereby improving the yield.

[0086] Unless otherwise defined, the terms used in the present invention have the meanings commonly understood by those skilled in the art.

[0087] The embodiments described in the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Those skilled in the art may make various other substitutions, changes and improvements within the scope of the present invention. Therefore, the present invention is not limited to the above embodiments, but is only limited by the claims.

Claims

1. A method for preparing a triazine compound, comprising: In an atmosphere containing carbon dioxide, a triazine intermediate is subjected to an etherification reaction with a halogenated alkane to obtain a triazine compound; wherein the structure of the triazine intermediate is as shown in Formula I, and the structure of the triazine compound is as shown in Formula II; wherein R1, R3, R4, R6, R7, and R9 are each independently selected from a hydroxyl group, a methyl group, a methoxy group, or a hydrogen atom, and at least two of R1, R3, R4, R6, R7, and R9 are hydroxyl groups, and R2, R5, and R8 are each independently selected from a methyl group or a hydrogen atom; E1, E2, E3, E4, E5, and E6 are each independently selected from a hydroxyl group, a methyl group, an alkoxy group containing 1 to 24 carbon atoms, or a hydrogen atom, and at least one of E1, E2, E3, E4, E5, and E6 is an alkoxy group containing 1 to 24 carbon atoms.

2. The preparation method according to claim 1, wherein In the gas containing carbon dioxide, the mass content of carbon dioxide is 60 to 100%; and / or, The halogenated alkane contains 1 to 24 carbon atoms; and / or, 1 to 4 of E1, E2, E3, E4, E5 and E6 are alkoxy groups containing 1 to 24 carbon atoms; and / or, In the structure of the triazine intermediate, R4 is a methoxy group, and at least two of R1, R3, R6, R7, and R9 are hydroxyl groups; or, R4 is a hydroxyl group, and at least one of R1, R3, R6, R7, and R9 is a hydroxyl group.

3. The preparation method according to claim 1, wherein In the structure of the triazine intermediate, each benzene ring contains two hydroxyl groups or no hydroxyl group; in the structure of the triazine compound, each benzene ring contains one or two hydroxyl groups or no hydroxyl group, and 1 to 4 groups among E1, E2, E3, E4, E5, and E6 are alkoxy groups containing 1 to 10 carbon atoms; and / or, The halogenated alkane contains 1 to 10 carbon atoms; and / or, The halogenated alkanes include brominated alkanes and / or chloroalkanes.

4. The preparation method according to claim 1, wherein The reaction system of the triazine intermediate and the halogenated alkane comprises a solvent, wherein the solvent comprises one or more of N,N-dimethylformamide and a sulfone solvent; and / or, The reaction system comprises a catalyst; and / or, In the structure of the triazine compound, at least one of E1, E2, E3, E4, E5 and E6 is an alkoxy group containing 1 to 24 carbon atoms, and at least one is a hydroxyl group.

5. The preparation method according to claim 4, wherein: The solvent is a sulfone solvent; and / or, The sulfone solvent includes one or more of sulfolane, diethyl sulfone, and diphenyl sulfone; and / or, The catalyst includes an inorganic basic compound.

6. The preparation method according to claim 5, wherein: The inorganic alkaline compound includes one or more of potassium carbonate, sodium carbonate, potassium hydroxide and sodium hydroxide.

7. The preparation method according to claim 1, wherein The reaction temperature of the etherification reaction is 60 to 150° C.; and / or, The mixed solution after the reaction is completed is filtered and subjected to a cooling and crystallization treatment to obtain the triazine compound.

8. The preparation method according to claim 7, wherein: The cooling crystallization is performed by a mixed solvent, wherein the mixed solvent comprises a sulfone solvent and an alcohol solvent.

9. The preparation method according to claim 8, wherein: The sulfone solvent includes one or more of sulfolane, diethyl sulfone, and diphenyl sulfone; the alcohol solvent includes one or more of methanol, ethanol, propanol, butanol, pentanol, and sec-butanol; and / or, The ratio of the sulfone solvent to the alcohol solvent is 1:(0.5-2.0).

10. The preparation method according to claim 1, wherein: The triazine intermediates include one or two of the following compounds: The triazine compounds include one or more of the following compounds:

Images