Synthesis method of bromo-hydrogenated polycyclic aromatic hydrocarbon

Abstract

According to the synthetic method of the brominated hydrogenated polycyclic aromatic hydrocarbon, hydrogenated polycyclic aromatic hydrocarbon and a brominating reagent are subjected to bromination reaction in a solvent in the presence of an initiator and an auxiliary agent to generate the brominated hydrogenated polycyclic aromatic hydrocarbon, and the bromination position is on a hydrogenation ring of the hydrogenated polycyclic aromatic hydrocarbon; the bromination reagent is liquid bromine. According to the method, cheap liquid bromine is adopted as a bromination reagent, bromination reaction can be conveniently carried out in the presence of an auxiliary agent, and no succinimide side reaction product is generated; meanwhile, the utilization rate of the liquid bromine is increased in the presence of the auxiliary agent, and the technical problems of high cost and complicated post-treatment in the existing synthesis process are solved.

Description

Technical Field

[0001] The present application relates to the technical field of organic synthesis, and in particular to a method for synthesizing brominated hydrogenated polycyclic aromatic hydrocarbons. Background Art

[0002] Polycyclic aromatic ketones are important dye and pesticide intermediates with a wide range of uses. Currently, the synthesis of polycyclic aromatic ketones can use N-bromosuccinimide (NBS) as a brominating agent to react with acenaphthene, but in this process, NBS is used in large amounts as a brominating agent, resulting in high synthesis costs and low yields of polycyclic aromatic ketones. In addition, the process generates succinimide byproducts, and the wastewater, waste gas, and waste residues are large in amount and need to be treated, resulting in a complex synthesis process. Related technologies also propose that bromohydrogenated polycyclic aromatic hydrocarbons can be used to generate corresponding polycyclic aromatic ketones or polycyclic aromatic aldehydes through the Kornblum reaction, but the current bromination process for hydrogenating polycyclic aromatic hydrocarbons uses N-bromosuccinimide as a brominating agent to synthesize bromohydrogenated polycyclic aromatic hydrocarbons, resulting in high synthesis costs, and the byproduct succinimide generated at the same time needs to be removed, and the synthesis process is complicated. Summary of the invention

[0003] The present application aims to solve at least one of the technical problems in the related art to a certain extent. The present application proposes a method for synthesizing brominated hydrogenated polycyclic aromatic hydrocarbons, wherein hydrogenated polycyclic aromatic hydrocarbons are reacted in the presence of a solvent, an initiator and an auxiliary agent using liquid bromine as a bromination reagent to generate brominated hydrogenated polycyclic aromatic hydrocarbons. The present application uses cheap liquid bromine as a bromination reagent, which has the advantage of low synthesis cost. At the same time, liquid bromine can be conveniently used in the presence of an auxiliary agent to carry out bromination reaction without the generation of succinimide side reaction products, and has the advantage of simple post-processing.

[0004] According to an embodiment of the present application, a method for synthesizing brominated hydrogenated polycyclic aromatic hydrocarbons is proposed, wherein hydrogenated polycyclic aromatic hydrocarbons are subjected to a bromination reaction with a brominating agent in a solvent in the presence of an initiator and an auxiliary agent to generate brominated hydrogenated polycyclic aromatic hydrocarbons, wherein the bromination position is on the hydrogenated ring of the hydrogenated polycyclic aromatic hydrocarbons; and the brominating agent is liquid bromine.

[0005] In some embodiments, the auxiliary agent includes sulfuryl chloride and thionyl chloride; based on the sulfuryl chloride, the mass percentage of the thionyl chloride is 0-20%.

[0006] In some embodiments, the number of aromatic rings in the hydrogenated polycyclic aromatic hydrocarbon is 2-4, and the number of hydrogenated rings is 1-2;

[0007] And / or, the hydrogenated polycyclic aromatic hydrocarbon has a structure as shown in formula (1)-(6):

[0008]

[0009] Wherein the substituents R1, R2, R3, R4, R5, R6, R7, and R8 are independently selected from hydrogen, chloro, fluoro, bromo, iodo, nitro, trifluoromethyl, hydroxyl, trichloromethyl, or an alkyl group having 1 to 8 carbon atoms.

[0010] In some embodiments, the initiator is a free radical initiator, which includes an azo initiator or an organic peroxide initiator.

[0011] In some embodiments, the solvent comprises a halogenated hydrocarbon, an aromatic hydrocarbon, an aromatic hydrocarbon substituted with a side chain halogen, or a hydrofluoroether;

[0012] The carbon number of the halogenated hydrocarbon is 1-6, and the halogen therein is at least one of fluorine, chlorine and bromine;

[0013] And / or, the aromatic hydrocarbon comprises benzene, nitrobenzene or halogen-containing alkylbenzene, wherein the halogen in the halogen-containing alkylbenzene is at least one of fluorine, chlorine and bromine,

[0014] and / or, the side chain halogen-substituted aromatic hydrocarbon includes trifluoromethylbenzene, trichloromethylbenzene, 1,3-bis(trifluoromethyl)benzene or difluoromethylbenzene;

[0015] And / or, the hydrofluoroether includes HFE-347, HFE-7100, HFE-7300, HFE-458 or HFE-6512.

[0016] In some embodiments, the molar ratio of the liquid bromine, the sulfuryl chloride in the auxiliary agent and the hydrogenated polycyclic aromatic hydrocarbons is (0.4-1.1): (0.4-1.2): 1;

[0017] and / or, the mass ratio of the solvent to the hydrogenated polycyclic aromatic hydrocarbon is 10-50:1;

[0018] And / or, based on the hydrogenated polycyclic aromatic hydrocarbon, the mass percentage of the initiator is 0.3-5%.

[0019] In some embodiments, the bromination reaction process comprises:

[0020] According to the stoichiometry, the hydrogenated polycyclic aromatic hydrocarbons, the initiator and the solvent are first mixed to form a first reaction liquid, and then heated to a set temperature T1; the mixture consisting of the liquid bromine and the auxiliary agent is added dropwise to the first reaction liquid within a time t1 and the reaction is continued for a time t2, and then the solvent is removed to obtain the brominated hydrogenated polycyclic aromatic hydrocarbons; wherein T1 is 50-120° C.; t1+t2=t 总1 ; t1 is 1-2h; t 总1 1-10h;

[0021] Alternatively, the hydrogenated polycyclic aromatic hydrocarbons, the initiator and part of the solvent are mixed according to the stoichiometric amount to form a second reaction liquid, and the mixture is heated to a set temperature T2; the mixture consisting of the liquid bromine and the auxiliary agent is diluted with the remaining solvent, and then dripped into the second reaction liquid within t3 time and continued to react for t4, and then the solvent is removed to obtain the brominated hydrogenated polycyclic aromatic hydrocarbons; wherein T2 is 50-120°C; t3+t4=t 总2 ; t3 is 1-2h; t 总2 1-10h;

[0022] Alternatively, the hydrogenated polycyclic aromatic hydrocarbons, the initiator, the auxiliary agent, the solvent and liquid bromine are mixed uniformly according to stoichiometry, heated to a set temperature T3 and reacted for a time of t5, and then the solvent is removed to obtain the brominated hydrogenated polycyclic aromatic hydrocarbons; wherein T3 is 50-120° C.; and t5 is 1-10 h.

[0023] In some embodiments, the brominated hydrogenated polycyclic aromatic hydrocarbons are monobrominated or polybrominated; when the brominated hydrogenated polycyclic aromatic hydrocarbons are polybrominated, one or two bromine atoms are introduced into the same carbon atom on the hydrogenated ring of the hydrogenated polycyclic aromatic hydrocarbons.

[0024] In some embodiments, the brominated hydrogenated polycyclic aromatic hydrocarbon is selected from the following structural formula:

[0025]

[0026]

[0027] At least one of the substituents X1, X2, and X3 is a bromine group, and the others are hydrogen groups.

[0028] In some embodiments, during the bromination reaction, the sulfuryl chloride and the liquid bromine form a mixture; the thionyl chloride is mixed with the hydrogenated polycyclic aromatic hydrocarbons, the initiator and the solvent to form a first reaction liquid or a second reaction liquid.

[0029] In the embodiments of the present application, cheap liquid bromine is used as a bromination reagent to solve the technical defect of high cost in the synthesis process in the related art. The bromination reaction can be conveniently carried out in the presence of an auxiliary agent. The two bromine atoms in the liquid bromine can be connected to the hydrogenated ring of the hydrogenated polycyclic aromatic hydrocarbons without the generation of succinimide side reaction products, which solves the technical problem of complex post-processing in the related art. At the same time, liquid bromine has a variety of addition methods in the synthesis method of the present application, which increases the flexibility and diversity of the process synthesis of the embodiment. In addition, the present application is carried out at a temperature of 50-120°C and its reaction conditions are mild.

[0030] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0032] Figure 1 This is the H NMR spectrum of 1-bromoacenaphthene provided in Example 1 of the present application. DETAILED DESCRIPTION

[0033] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as limiting the present application. On the contrary, the present application includes all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0034] Related technologies provide that the bromination process of hydrogenated polycyclic aromatic hydrocarbons all uses N-bromosuccinimide as a bromination reagent, resulting in high synthesis costs, and the by-product succinimide needs to be filtered and removed, and the process steps are long and complicated. Based on this, the technical scheme of the embodiment of the present application provides a method for synthesizing brominated hydrogenated polycyclic aromatic hydrocarbons, using liquid bromine as a bromination reagent to bromine the hydrogenated polycyclic aromatic hydrocarbons in the presence of an initiator and an auxiliary agent and a bromination reagent in a solvent to generate brominated hydrogenated polycyclic aromatic hydrocarbons, wherein the bromination position is on the hydrogenation ring of the hydrogenated polycyclic aromatic hydrocarbons. This method solves the technical problems of high cost and complex post-processing in the existing synthesis process.

[0035] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0036] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0037] To achieve the above-mentioned purpose, according to the embodiments of the present application, a method for synthesizing brominated hydrogenated polycyclic aromatic hydrocarbons is proposed, in which hydrogenated polycyclic aromatic hydrocarbons are subjected to a bromination reaction with a brominating agent in a solvent in the presence of an initiator and an auxiliary agent to generate brominated hydrogenated polycyclic aromatic hydrocarbons, wherein the bromination position is on the hydrogenated ring of the hydrogenated polycyclic aromatic hydrocarbons; the brominating agent is liquid bromine.

[0038] Among them, the bromination reaction process includes the following three schemes.

[0039] The first scheme: according to the stoichiometric method, the hydrogenated polycyclic aromatic hydrocarbons, the initiator and the solvent are first mixed to form a first reaction liquid, and then heated to a set temperature T1; the mixture consisting of liquid bromine and the auxiliary agent is added dropwise to the first reaction liquid within a time of t1 and the reaction is continued for a time of t2, and then the solvent is removed to obtain brominated hydrogenated polycyclic aromatic hydrocarbons; wherein T1 is 50-120°C; t1+t2=t 总1 ; t1 is 1-2h; t 总1 1-10h.

[0040] The second scheme is: firstly, hydrogenated polycyclic aromatic hydrocarbons, initiators and part of the solvent are mixed according to the stoichiometric amount to form a second reaction liquid, and then heated to a set temperature T2; the mixture of liquid bromine and the auxiliary agent is diluted with the remaining solvent, and then dripped into the second reaction liquid within t3 time and continued to react for t4, and then the solvent is removed to obtain brominated hydrogenated polycyclic aromatic hydrocarbons; wherein T2 is 50-120°C; t3+t4=t 总2 ; t3 is 1-2h; t 总2 1-10h;

[0041] The third scheme: hydrogenated polycyclic aromatic hydrocarbons, initiator, auxiliary agent, solvent and liquid bromine are mixed according to stoichiometry, heated to a set temperature T3 and reacted for a time of t5, and then the solvent is removed to obtain brominated hydrogenated polycyclic aromatic hydrocarbons; wherein T3 is 50-120°C; t5 is 1-10h.

[0042] Taking the first scheme as an example, the bromination reaction process is described illustratively: it includes step (1) and step (2).

[0043] Step (1): mixing hydrogenated polycyclic aromatic hydrocarbons, an initiator and a solvent according to stoichiometric amounts to form a first reaction liquid and heating the mixture to a set temperature T1; wherein the number of aromatic rings in the hydrogenated polycyclic aromatic hydrocarbons is 2-4, the number of hydrogenated rings is 1-2, and the hydrogenated polycyclic aromatic hydrocarbons have structures as shown in formulas (1) to (6):

[0044]

[0045] In the structures shown in formulas (1) to (6), the substituents R1, R2, R3, R4, R5, R6, R7, and R8 are independently selected from hydrogen, chloro, fluoro, bromo, iodo, nitro, trifluoromethyl, hydroxyl, trichloromethyl, or an alkyl group having 1 to 8 carbon atoms. For example, the hydrogenated polycyclic aromatic hydrocarbons are dihydroacenaphthene, 2-chlorofluorene, 4,5,9,10-tetrahydropyrene, 9,10-dihydrophenanthrene, and the like.

[0046] Among them, the initiator in this embodiment is a free radical initiator, which includes an azo initiator or an organic peroxide initiator; for example, the initiator includes azoisobutyronitrile, azobisisoheptanenitrile, azobiscyclohexylcarbonitrile, benzoyl peroxide, tert-butyl benzoyl peroxide or methyl ethyl ketone peroxide.

[0047] The solvent in this embodiment includes halogenated hydrocarbons, aromatic hydrocarbons, aromatic hydrocarbons substituted with side chain halogens or hydrofluoroethers; wherein the carbon number of the halogenated hydrocarbons is 1-6, and the halogen therein is at least one of fluorine, chlorine and bromine, such as carbon tetrachloride, ethyl chloride, n-butyl chloride, isobutyl fluoride, secondary butyl bromide, tertiary butyl iodide, etc.; aromatic hydrocarbons include benzene, nitrobenzene or halogen-containing alkylbenzenes, wherein the halogen in the halogen-containing alkylbenzenes is at least one of fluorine, chlorine and bromine, such as; chlorobenzene, bromobenzene, fluorobenzene, etc. Aromatic hydrocarbons substituted with side chain halogens include trifluoromethylbenzene, trichloromethylbenzene, 1,3-bis(trifluoromethyl)benzene or difluoromethylbenzene; hydrofluoroethers include HFE-347, HFE-7100, HFE-7300, HFE-458 or HFE-6512.

[0048] The mass ratio of the solvent to the hydrogenated polycyclic aromatic hydrocarbons is 10-50:1; for example, the mass ratio of the solvent to the hydrogenated polycyclic aromatic hydrocarbons is (10, 15, 20, 30, 35, 40, 45, 50):1, wherein the amount of solvent used is too small, such as the mass ratio of the solvent to the hydrogenated polycyclic aromatic hydrocarbons is less than 10, the dissolution effect of the raw material hydrogenated polycyclic aromatic hydrocarbons is poor, and the bromination reaction effect is poor; the amount of solvent used is too large, such as the mass ratio of the solvent to the hydrogenated polycyclic aromatic hydrocarbons is less than or greater than 50, which is unnecessary and reduces the concentration of the hydrogenated polycyclic aromatic hydrocarbons, resulting in a slower reaction rate and a longer reaction time.

[0049] Among them, based on the hydrogenated polycyclic aromatic hydrocarbons, the mass percentage of the initiator is 0.3-5%; for example, based on the hydrogenated polycyclic aromatic hydrocarbons, the mass percentage of the initiator is 0.3%, 1%, 2%, 3%, 4% or 5%, etc., wherein when the amount of the initiator is small, such as less than 0.3%, the bromination reaction rate is slow and the reaction time is long; but when the amount of the initiator is large, such as greater than 5%, the reaction is violent and the side reactions increase.

[0050] Step (2): adding a mixture of liquid bromine and an auxiliary agent dropwise to the first reaction liquid within a time period of t1 and continuing the reaction for a time period of t2, and then removing the solvent to obtain brominated hydrogenated polycyclic aromatic hydrocarbons; wherein T1 is 50-120°C; t1+t2=t 总1 ; t1 is 1-2h; t 总1 1-10h.

[0051] The auxiliary agent includes sulfuryl chloride and thionyl chloride; the mass percentage of thionyl chloride is 0-20% based on sulfuryl chloride. For example, the mass percentage of thionyl chloride is 0%, 1%, 2%, 3%, 4%, 5%, 10%, 12%, 13%, 14%, 15%, 16%, 18%, 20%, etc. based on sulfuryl chloride, wherein thionyl chloride has the function of effectively reducing the generation of aromatic ring substitution side reaction.

[0052] The molar ratio of sulfuryl chloride in the auxiliary agent to hydrogenated polycyclic aromatic hydrocarbons is (0.4-1.2):1; for example, the molar ratio of sulfuryl chloride to hydrogenated polycyclic aromatic hydrocarbons is (0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2):1; the molar ratio of the brominating agent to the sulfuryl chloride in the auxiliary agent is (0.4-1.1):(0.4-1.2); for example, the molar ratio of the brominating agent to the sulfuryl chloride in the auxiliary agent is (0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1):(0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2). When the amount of bromination reagent and sulfuryl chloride used is small, the conversion rate of raw material hydrogenation polycyclic aromatic hydrocarbons is low; when the amount of bromination reagent and sulfuryl chloride used is large, the amount of polybrominated substitution products generated is large, and the selectivity of monobrominated substitution products is low.

[0053] The reaction temperature has an important influence on the reaction rate. In this embodiment, the reaction temperature is 50-120°C, and the further reaction temperature is 50-100°C, for example, 50°C, 60°C, 70°C, 80°C, 90°C and 100°C; when the temperature is too high, such as above 120°C, the initiator decomposes quickly, the reaction is violent, and polybrominated products are easily generated; when the temperature is too low, such as below 50°C, the reaction time is long, and the raw material hydrogenation polycyclic aromatic hydrocarbons are not completely reacted. In addition, the mixture of liquid bromine and the auxiliary agent is added dropwise to the first reaction liquid within 1-2h, and then the reaction time t2 is continued. In this application, the reaction time is 1-10h.

[0054] In this embodiment, the brominated hydrogenated polycyclic aromatic hydrocarbons are monobrominated or polybrominated. When the brominated hydrogenated polycyclic aromatic hydrocarbons are polybrominated, one or two bromine atoms are introduced into the same carbon atom on the hydrogenated ring of the hydrogenated polycyclic aromatic hydrocarbons. For example, the brominated hydrogenated polycyclic aromatic hydrocarbons are selected from the following structural formulas:

[0055]

[0056]

[0057] At least one of the substituents X1, X2, and X3 is a bromine group, and the others are hydrogen groups.

[0058] It should be explained that, during the bromination reaction, sulfuryl chloride and liquid bromine form a mixture; thionyl chloride is mixed with hydrogenated polycyclic aromatic hydrocarbons, initiator and solvent to form a first reaction liquid or a second reaction liquid. In other words, in step (1) of this embodiment, hydrogenated polycyclic aromatic hydrocarbons, initiator, solvent and thionyl chloride are mixed according to stoichiometry to form a first reaction liquid and heated to a set temperature T1; in step (2), a mixture of liquid bromine and sulfuryl chloride is added dropwise to the first reaction liquid within a time of t1 and the reaction is continued for a time of t2, and then the solvent is removed to obtain brominated hydrogenated polycyclic aromatic hydrocarbons.

[0059] The bromination reaction process of the second scheme is different from the bromination reaction process of the first scheme in that a mixture consisting of a part of the solvent, liquid bromine and an auxiliary agent is diluted and then added dropwise to a mixture of hydrogenated polycyclic aromatic hydrocarbons, an initiator and a part of the solvent to form a second reaction liquid. Other technical features can refer to the above content and will not be repeated here.

[0060] In the bromination reaction of the second scheme, hydrogenated polycyclic aromatic hydrocarbons, initiators, auxiliary agents (sulfuryl chloride, thionyl chloride), solvents and liquid bromine are mixed according to stoichiometry and heated to a set temperature T3 and reacted for a time of t5, and then the solvent is removed to obtain brominated hydrogenated polycyclic aromatic hydrocarbons; wherein T3 is 50-120°C; t5 is 1-10h. The reaction temperature T3 is 50-120°C, and the further reaction temperature is 50-100°C. The reaction time t5 in this application is 1-10h. Other technical features can refer to the above content and will not be repeated.

[0061] To facilitate further understanding of the present application, the scheme of the present application is further described below in conjunction with the embodiments. Those skilled in the art will understand that the description in the present application is only part of the examples, and any other suitable specific examples are within the scope of the present application.

[0062] Example 1

[0063] In a 500ml four-necked flask with a condenser, 15.2g (0.1mol) of dihydroacenaphthene, 300g of carbon tetrachloride, 0.2g of azoisobutyronitrile, and 0.8g of thionyl chloride were added, stirred, and heated to 70°C. A mixture consisting of 8.8g (0.055mol) of liquid bromine and 7.43g (0.055mol) of sulfuryl chloride was added within 1h. After the addition was completed, the reaction was continued for 6h, cooled, and the solvent was removed by rotary evaporation to obtain 24.1g of a solid mixture. Sampling and analysis showed that the conversion rate of dihydroacenaphthene was 97.4%, and the selectivity of 1-bromodihydroacenaphthene was 92.2%. The nuclear magnetic hydrogen spectrum of 1-bromodihydroacenaphthene is shown as follows: Figure 1 As shown, the content of the substituted byproduct on the aromatic ring of dihydroacenaphthene is 1.2%.

[0064] Example 2

[0065] In a 1000ml four-necked flask with a condenser, 20.1g (0.1mol) of 2-chlorofluorene, 600g of 1,3-bistrifluoromethylbenzene, 0.6g of benzoyl peroxide, and 2.4g of thionyl chloride were added, stirred, and heated to 120°C. A mixture consisting of 17.6g (0.11mol) of liquid bromine and 16.2g (0.12mol) of sulfuryl chloride was added within 2h. After the addition was completed, the reaction was continued for 2h, and the solvent was removed by rotary evaporation to obtain 38.4g of a solid mixture. Sampling and analysis showed that the conversion rate of 2-chlorofluorene was 98.6%. By analyzing the spectral data, 9,9-dibromo-2-chlorofluorene was obtained in this embodiment, wherein the selectivity of 9,9-dibromo-2-chlorofluorene was 92.4%, and the content of substituted by-products on the aromatic ring was 1.1%.

[0066] Example 3

[0067] In a 1000ml four-necked flask with a condenser, 20.1g (0.1mol) of 4,5,9,10-tetrahydropyrene, 900g of chlorobenzene, 1.0g of azobisisovaleronitrile, 1.2g of thionyl chloride, 6.4g (0.04mol) of liquid bromine, and 6g (0.045mol) of sulfuryl chloride were added, stirred, heated to 50°C, reacted for 8h, and the solvent was removed by rotary evaporation to obtain 30.1g of a solid mixture. Sampling and analysis showed that the conversion rate of 4,5,9,10-tetrahydropyrene was 78.4%, the selectivity of the monobromine substitution on the hydrogenation ring was 91.6%, and the content of the substituted by-product on the aromatic ring was 1.6%.

[0068] Example 4

[0069] In a 500ml four-necked flask with a condenser, add 18g (0.1mol) 9,10-dihydrophenanthrene, 180g HFE-6512, 0.1g azobisisobutyronitrile, 0.5g thionyl chloride, stir, stir, heat to 80°C, and add a mixture of 12g (0.075mol) liquid bromine, 10g (0.075mol) sulfuryl chloride and 50g HFE-6512 within 2h. After the addition is completed, continue the reaction for 4h, remove the solvent by rotary evaporation, and obtain 29.5g solid mixture. Sampling and analysis show that the conversion rate of 9,10-dihydrophenanthrene is 99.6%, the selectivity of monobromo-substituted dihydrophenanthrene is 52.6%, the selectivity of dibromo-substituted is 43.7%, and the content of substituted byproducts on the aromatic ring is 1.9%.

[0070] Example 5

[0071] In a 500ml four-necked flask with a condenser, 15.2g (0.1mol) of dihydroacenaphthene, 300g of carbon tetrachloride, and 0.2g of azoisobutyronitrile were added, stirred, and heated to 70°C. A mixture consisting of 8.8g (0.055mol) of liquid bromine and 7.43g (0.055mol) of sulfuryl chloride was added within 1h. After the addition was completed, the reaction was continued for 6h, cooled, and the solvent was removed by rotary evaporation to obtain 24.5g of a solid mixture. Sampling and analysis showed that the conversion rate of dihydroacenaphthene was 97.6%. By analyzing the spectral data, 1-bromodihydroacenaphthene was obtained in this embodiment, wherein the selectivity of 1-bromodihydroacenaphthene was 91.4%, and the content of substituted by-products on the aromatic ring of dihydroacenaphthene was 3.2%.

[0072] Example 6

[0073] In a 500ml four-necked flask with a condenser, 15.2g (0.1mol) of dihydroacenaphthene, 250g of carbon tetrachloride, and 0.2g of azoisobutyronitrile were added, stirred, and heated to 70°C. A mixture consisting of 8.8g (0.055mol) of liquid bromine, 7.43g (0.055mol) of sulfuryl chloride and 50g of carbon tetrachloride was added within 1h. After the addition was completed, the reaction was continued for 6h, cooled, and the solvent was removed by rotary evaporation to obtain 24.5g of a solid mixture. Sampling and analysis showed that the conversion rate of dihydroacenaphthene was 96.8%, the selectivity of 1-bromodihydroacenaphthene was 91.7%, and the content of substituted by-products on the aromatic ring of dihydroacenaphthene was 2.8%.

[0074] Comparative Example 1

[0075] In a 500ml four-necked flask with a condenser, 15.2g (0.1mol) of dihydroacenaphthene, 300g of carbon tetrachloride, 0.2g of azoisobutyronitrile, and 19.6g (0.11mol) of N-bromosuccinimide were added, stirred, heated to 70°C, reacted for 6h, cooled, and the solvent was removed by rotary evaporation to obtain 24.1g of a solid mixture. After sampling and analysis, the conversion rate of dihydroacenaphthene was 76.4%, the selectivity of 1-bromoacenaphthene was 81.6%, and the content of substituted by-products on the aromatic ring of dihydroacenaphthene was 2.4%.

[0076] Comparative Example 2

[0077] In a 1000ml four-necked flask with a condenser, 20.1g (0.1mol) of 2-chlorofluorene, 600g of 1,3-bistrifluoromethylbenzene, 0.6g of benzoyl peroxide and 2.4g of thionyl chloride were added, stirred and heated to 120°C. Within 2h, 17.6g (0.11mol) of bromine was added. After the addition was completed, the reaction was continued for 2h. The solvent was removed by rotary evaporation to obtain 24.5g of a solid mixture. Sampling and analysis showed that the conversion rate of 2-chlorofluorene was 27.6%, the selectivity of 9-bromo-2-chlorofluorene was 83.4%, and the content of substituted by-products on the aromatic ring was 1.4%.

[0078] Comparative Example 3

[0079] In a 1000ml four-necked flask with a condenser, 20.1g (0.1mol) of 4,5,9,10-tetrahydropyrene, 900g of chlorobenzene, 1.0g of azobisisovaleronitrile, 1.2g of thionyl chloride, 4.8g (0.03mol) of liquid bromine, and 6g (0.045mol) of sulfuryl chloride were added, stirred, heated to 50°C, reacted for 8h, and the solvent was removed by rotary evaporation to obtain 26.2g of a solid mixture. Sampling and analysis showed that the conversion rate of 4,5,9,10-tetrahydropyrene was 71.2%, the selectivity of the monobromine substitution on the hydrogenation ring was 74.6%, and the content of the substituted by-product on the aromatic ring was 1.8%.

[0080] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0081] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for synthesizing brominated hydrogenated polycyclic aromatic hydrocarbons, characterized in that: The hydrogenated polycyclic aromatic hydrocarbons are subjected to a bromination reaction with a brominating agent in a solvent in the presence of an initiator and an auxiliary agent to generate brominated hydrogenated polycyclic aromatic hydrocarbons, wherein the bromination position is on the hydrogenated ring of the hydrogenated polycyclic aromatic hydrocarbons; and the brominating agent is liquid bromine.

2. The synthesis method according to claim 1, characterized in that The auxiliary agent comprises sulfuryl chloride and thionyl chloride; based on the sulfuryl chloride, the mass percentage content of the thionyl chloride is 0-20%.

3. The synthesis method according to claim 2, characterized in that The number of aromatic rings in the hydrogenated polycyclic aromatic hydrocarbon is 2-4, and the number of hydrogenated rings is 1-2; And / or, the hydrogenated polycyclic aromatic hydrocarbon has a structure as shown in formula (1)-(6): Wherein the substituents R1, R2, R3, R4, R5, R6, R7, and R8 are independently selected from hydrogen, chloro, fluoro, bromo, iodo, nitro, trifluoromethyl, hydroxyl, trichloromethyl, or an alkyl group having 1 to 8 carbon atoms.

4. The synthesis method according to claim 2, characterized in that The initiator is a free radical initiator, which includes an azo initiator or an organic peroxide initiator.

5. The synthesis method according to claim 2, characterized in that The solvent includes halogenated hydrocarbons, aromatic hydrocarbons, aromatic hydrocarbons substituted with side chain halogens or hydrofluoroethers; The carbon number of the halogenated hydrocarbon is 1-6, and the halogen therein is at least one of fluorine, chlorine and bromine; And / or, the aromatic hydrocarbon comprises benzene, nitrobenzene or halogen-containing alkylbenzene, wherein the halogen in the halogen-containing alkylbenzene is at least one of fluorine, chlorine and bromine, and / or, the side chain halogen-substituted aromatic hydrocarbon includes trifluoromethylbenzene, trichloromethylbenzene, 1,3-bis(trifluoromethyl)benzene or difluoromethylbenzene; And / or, the hydrofluoroether includes HFE-347, HFE-7100, HFE-7300, HFE-458 or HFE-6512.

6. The synthesis method according to any one of claims 2 to 5, characterized in that: The molar ratio of the liquid bromine, the sulfuryl chloride in the auxiliary agent and the hydrogenated polycyclic aromatic hydrocarbons is (0.4-1.1): (0.4-1.2): 1; and / or, the mass ratio of the solvent to the hydrogenated polycyclic aromatic hydrocarbon is 10-50:1; And / or, based on the hydrogenated polycyclic aromatic hydrocarbon, the mass percentage of the initiator is 0.3-5%.

7. The synthesis method according to claim 6, characterized in that The bromination reaction process includes: According to the stoichiometry, the hydrogenated polycyclic aromatic hydrocarbons, the initiator and the solvent are first mixed to form a first reaction liquid, and then heated to a set temperature T1; the mixture consisting of the liquid bromine and the auxiliary agent is added dropwise to the first reaction liquid within a time t1 and the reaction is continued for a time t2, and then the solvent is removed to obtain the brominated hydrogenated polycyclic aromatic hydrocarbons; wherein T1 is 50-120° C.; t1+t2=t 总1 ; t1 is 1-2h; t 总1 1-10h; Alternatively, the hydrogenated polycyclic aromatic hydrocarbons, the initiator and part of the solvent are mixed according to the stoichiometric amount to form a second reaction liquid, and the mixture is heated to a set temperature T2; the mixture consisting of the liquid bromine and the auxiliary agent is diluted with the remaining solvent, and then dripped into the second reaction liquid within t3 time and continued to react for t4, and then the solvent is removed to obtain the brominated hydrogenated polycyclic aromatic hydrocarbons; wherein T2 is 50-120°C; t3+t4=t 总2 ; t3 is 1-2h; t 总2 1-10h; Alternatively, the hydrogenated polycyclic aromatic hydrocarbons, the initiator, the auxiliary agent, the solvent and liquid bromine are mixed uniformly according to stoichiometry, heated to a set temperature T3 and reacted for a time of t5, and then the solvent is removed to obtain the brominated hydrogenated polycyclic aromatic hydrocarbons; wherein T3 is 50-120° C.; and t5 is 1-10 h.

8. The synthesis method according to claim 1, characterized in that The brominated hydrogenated polycyclic aromatic hydrocarbons are monobrominated or polybrominated; when the brominated hydrogenated polycyclic aromatic hydrocarbons are polybrominated, one or two bromine atoms are introduced into the same carbon atom on the hydrogenated ring of the hydrogenated polycyclic aromatic hydrocarbons.

9. The synthesis method according to claim 8, characterized in that The brominated hydrogenated polycyclic aromatic hydrocarbons are selected from the following structural formulas: At least one of the substituents X1, X2, and X3 is a bromine group, and the others are hydrogen groups.

10. The synthesis method according to claim 7, characterized in that: During the bromination reaction, the sulfuryl chloride and the liquid bromine form a mixture; the thionyl chloride is mixed with the hydrogenated polycyclic aromatic hydrocarbons, the initiator and the solvent to form a first reaction liquid or a second reaction liquid.

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