Preparation method for parylene-series product and parylene-series product

Abstract

A preparation method for a parylene-series product, and a parylene-series product. The preparation method for a parylene-series product comprises the following steps: S1, reacting a compound 1 and a compound 2 with N,N,N',N'-tetramethyldiaminomethane to obtain diquaternary ammonium salt; and S2, carrying out an elimination reaction on the diquaternary ammonium salt and a catalyst under an alkaline condition to obtain a parylene-series product as shown in general formula (I), wherein the structural formulas of the compound 1, the compound 2 and the diquaternary ammonium salt are as shown in general formulas (II), (III) and (IV), respectively. Various benzyl halides are reacted with N,N,N',N'-tetramethyldiaminomethane to obtain diquaternary ammonium salt having a linker arm, and a p-quinodimethane intermediate state is formed, so that the intermediate state is prevented from being linked end to end to generate a linear polymerization side reaction, and the parylene-series product can be efficiently prepared.

Description

A preparation method of parylene series products and parylene series products

[0001] This application is based on the Chinese application with CN application number 202311092823.7 and application date August 29, 2023, and claims its priority. The disclosed content of the CN application is again introduced as a whole into this application. Technical Field

[0002] The present invention belongs to the technical field of organic chemistry, and particularly relates to a preparation method of a parylene series product and the parylene series product. Background Art

[0003] Parylene, a new conformal coating material developed and applied in the 1970s, is a polymer of p-xylene. The raw material for parylene coating is cyclic p-xylene dimer. Parylene powders can be divided into parylene N powder, C powder, D powder, F powder, and HT powder, depending on the chemical structure of the cyclic p-xylene dimer.

[0004] When using Parylene powder, the various series of cyclic p-xylene dimer powders mentioned above are first placed in the evaporation furnace of the coating equipment. Under vacuum conditions at 150°C, the solid raw material is converted into a gaseous state. Then, through pyrolysis at 650-700°C, the gaseous raw material is cracked into reactive monomers. These reactive monomers, under vacuum and cooling conditions, form linear polymers, which form a transparent insulating coating. This provides components with a complete, high-quality protective coating, protecting against acid, alkali, salt spray, mold, and various corrosive gases. Currently, Parylene coating technology is widely used in aerospace, new energy vehicles, circuit boards, magnetic materials, sensors, silicone rubber, seals, medical devices, and precious cultural relics.

[0005] Currently, the main chemical synthesis methods for Parylene powders include photodesulfurization, metal coupling, and Hofmann elimination. These methods generally have many disadvantages, such as expensive raw materials, low production efficiency, and difficulty in large-scale production.

[0006] Masaaki Iwata et al. used photodesulfurization to desulfurize cyclic disulfides under high-pressure mercury lamp irradiation to produce parylene N powder derivatives, achieving laboratory yields exceeding 50%. However, the raw cyclic disulfide must be prepared at an extremely dilute concentration, resulting in extremely low production efficiency and unsuitable for large-scale production (Bull. Chem. Soc. Jpn., 58, 2502-2514).

[0007] Specialty Coating Systems, Inc. of the United States has published a method for preparing parylene HT powder using a metal coupling method (WO1998041490A1), but this method produces heptafluorine impurities that are difficult to separate and purify.

[0008] In 2018, Shanghai Qixin New Materials Technology Co., Ltd. reported a method for preparing parylene F powder using 2,3,5,6-tetrafluoro-4-dichloromethylbenzene as a raw material through a zinc powder-mediated coupling reaction (CN109232168A). This method produces trimers and polymers, which are difficult to separate and purify, and the yield is low.

[0009] The aforementioned metal coupling method for preparing parylene powder requires the use of dibenzyl chloride intermediate raw materials 2,3,5,6-tetrafluoro-p-dichloromethylbenzene (TFC) and 1,4-bis(chlorodifluoromethyl)benzene (DCTF). DCTF and TFC require multiple steps of harsh reaction conditions to produce, resulting in high production costs, which seriously restricts the industrial application of this technology.

[0010] Hak-Fun Chow et al. from the Chinese University of Hong Kong published a method for preparing parylene N powder by using the quaternary ammonium salt of p-methylbenzyl chloride as a raw material through a Hofmann elimination reaction. However, the disadvantage is that the yield is only 10-20%.

[0011] Since the 1970s, scientists from various countries have discovered during the research and development of synthetic processes for parylene powders that the traditional quaternary ammonium salt Hofmann elimination method for preparing parylene compounds is prone to undergoing end-to-end linear polymerization reactions, as shown below. This converts the main product into a polymer, ultimately resulting in extremely low yields of the target product and ineffective cost control.

[0012] Therefore, the industry is in urgent need of developing a method for preparing a series of parylene products with simple process and low cost.

[0013] Summary of the Invention

[0014] In view of the shortcomings of the prior art, the present invention aims to provide a method for preparing a series of parylene products with simple process and high efficiency, thereby improving the reaction yield.

[0015] To achieve this object, the present invention adopts the following technical solutions:

[0016] The first object of the present invention is to provide a method for preparing a parylene series product, comprising the following steps:

[0017] S1. Compound 1 and Compound 2 react with N,N,N',N'-tetramethyldiaminomethane to obtain a diquaternary ammonium salt;

[0018] S2. The diquaternary ammonium salt and the catalyst undergo elimination reaction under alkaline conditions to obtain a series of products of the formula shown in Formula Ⅰ;

[0019] The structural formulas of compound 1, compound 2, and diquaternary ammonium salt are respectively represented by formula II, formula III, and formula IV:

[0020] Wherein, R1, R2, R3, R4, R5, R6, R7, and R8 are each independently selected from a hydrogen atom, a halogen, an amino group, a nitro group, an ester group, an aldehyde group, a methoxy group, an ethoxy group, a cyano group, a trifluoromethyl group, an ethynyl group, a vinyl group, and a saturated alkyl group; and X and Y are each independently selected from a fluorine, a chlorine, a bromine, or an iodine atom.

[0021] Preferably, the number of carbon atoms in the saturated alkyl group is not greater than 8, and includes at least one of a linear or branched methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.

[0022] Reaction flow chart of the present invention is as follows:

[0023] Specifically, in step S2, the elimination reaction forms a quinodimethane intermediate having the general formula shown in Formula V:

[0024] The p-quinodimethane intermediate undergoes a ring-closing reaction to form a series of parylene products of the general formula shown in Formula I, wherein m is at least one of 1, 2, 3, and 4, and n is at least one of 5, 6, 7, and 8.

[0025] Specifically, in step S2, the catalyst is a quaternary ammonium salt and / or a quaternary phosphonium salt;

[0026] Preferably, the catalyst includes at least one of triphenylmethylphosphonium bromide, tetraphenylphosphonium bromide, tetrabutylphosphonium hydroxide, benzyltriphenylphosphonium chloride, hexadecyltributylphosphonium chloride, hexadecyltrihexylphosphonium chloride, allyltriphenylphosphonium chloride, pentyltributylphosphonium chloride, benzyltributylphosphonium chloride, propyltriphenylphosphonium chloride and other quaternary phosphonium salts, benzyltributylammonium chloride, tetrabutylammonium bromide and tetrabutylammonium chloride.

[0027] Specifically, in step S1, compound 1 and compound 2 are independently selected from at least one of the following structural formulas:

[0028] Specifically, the parylene series products are selected from at least one of the following structural formulas:

[0029] Specifically, step S2 is carried out under alkaline conditions, and the base selected is an inorganic strong base;

[0030] Preferably, the inorganic strong base is one or more selected from NaOH, KOH, LiOH, RbOH, CsOH, GrOH, Ca(OH)2, Sr(OH)2, Ba(OH)2 and Ra(OH)2.

[0031] Specifically, in step S1, the molar ratio of compound 1 to compound 2 is 1:1, and the molar ratio of compound 1 to N,N,N',N'-tetramethyldiaminomethane is (0.9-1):1;

[0032] Preferably, the reaction temperature is 10-50°C and the reaction time is 2-5 hours.

[0033] Specifically, in step S2, the molar ratio of the total feed of compound 1 and compound 2 to the feed of the catalyst is 100:(0.1-1);

[0034] Preferably, the temperature of the elimination reaction is 90-120° C., and the time is 18-30 hours.

[0035] Among them, preferably, the feed ratio of the compound 1 and the N,N,N',N'-tetramethyldiaminomethane can be 0.9:1, 0.91:1, 0.92:1, 0.93:1, 0.94:1, 0.95:1, 0.96:1, 0.97:1, 0.98:1, 0.99:1 or 1:1, etc.; more preferably, the reaction temperature can be 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C or 50°C, etc., and the reaction time can be 2h, 2.5h, 3h, 3.5h, 4h, 4.5h or 5h, etc., but are not limited to the values ​​listed above. Other values ​​not listed within the above numerical range are also applicable.

[0036] Among them, preferably, in step S2, the molar ratio of the total feed of compound 1 and compound 2 to the feed of the catalyst is 100:0.1, 100:0.2, 100:0.3, 100:0.4, 100:0.5, 100:0.6, 100:0.7, 100:0.8, 100:0.9 or 100:1, etc.; more preferably, the temperature of the elimination reaction can be 90°C, 95°C, 100°C, 105°C, 110°C, 115°C or 120°C, and the time can be 18h, 19h, 20h, 21h, 22h, 23h, 24h, 25h, 26h, 27h, 28h, 29h or 30h, etc., but are not limited to the values ​​listed above, and other values ​​not listed within the above numerical range are equally applicable.

[0037] Specifically, step S1 further comprises a first solvent, which is one or more selected from dichloromethane, methanol, ethanol, isopropanol, tetrahydrofuran, toluene, 1,4-dioxane, and N,N-dimethylformamide; step S2 further comprises a second solvent having a boiling point greater than 85°C, which is at least two selected from xylene, dimethyl sulfoxide, toluene, anisole, 1,4-dioxane, mesitylene, and chlorobenzene.

[0038] The second object of the present invention is to provide a parylene series product, which is prepared by the above-mentioned preparation method, wherein the parylene series product is selected from at least one of the following structural formulas:

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The invention provides a preparation method of a parylene series product and the parylene series products. Various benzyl halides are reacted with N,N,N',N'-tetramethyldiaminomethane to prepare a diquaternary ammonium salt with a connecting arm. In the presence of a catalyst and alkaline conditions, the diquaternary ammonium salt with the connecting arm undergoes an elimination reaction to cause intramolecular degradation, releasing N,N,N',N'-tetramethyldiaminomethane while forming a p-quinodimethane intermediate state. Since the two benzyl rings of the p-quinodimethane intermediate state are more inclined to undergo a face-to-face ring-closure reaction due to the π-π conjugation effect, a linear polymerization side reaction caused by the end-to-end connection of the p-quinodimethane intermediate state can be effectively avoided, thereby greatly improving the reaction yield. Parylene series products such as parylene N powder, C powder, D powder, F powder, and halogen-free C powder can be efficiently prepared. DETAILED DESCRIPTION

[0041] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0042] Example 1

[0043] This embodiment provides a preparation method of a parylene series product (parylene N powder) and a parylene series product, and the reaction equation is as follows:

[0044] The specific steps include:

[0045] S1. 4-(Chloromethyl)-1-methylbenzene (1.1 mol) and N,N,N',N'-tetramethyldiaminomethane (0.5 mol) were added to dichloromethane (500 ml) in sequence, and the reaction was stirred at 20 ° C for 5 hours. After the reaction was completed, the solvent was removed under reduced pressure to obtain a crude solid product, which was slurried with methyl tert-butyl ether (200 mL) to obtain diquaternary ammonium salt JA-1 (0.45 mol) with a yield of 90%;

[0046] S2. A 51% KOH (6.09 mol) aqueous solution (669 g), xylene (1000 mL), dimethyl sulfoxide (430 mL), and benzyltriphenylphosphonium chloride (0.004 mol) were added to a reaction flask. Under stirring, an aqueous solution (500 mL) containing 0.4 mol of diquaternary ammonium salt JA-1 was added dropwise at 90°C over 4 hours. The reaction was maintained at 90°C for 24 hours. The reaction solution was allowed to stand and separate. The upper xylene phase was removed, washed with water, and decolorized with activated carbon. The filtrate was concentrated by distillation to 750 mL and cooled to crystallize to obtain white crystals. The product was then dried under vacuum at 50°C to obtain 58.3 g of parylene N powder (0.28 mol), with a yield of 70%.

[0047] The NMR characterization data are as follows: 1 H NMR (400MHz, CDCl3): δ3.09(s,8H,ArCH2), 6.50(s,8H,ArH).

[0048] Example 2

[0049] This example provides a method for preparing a parylene series product (parylene N powder) and the parylene series product, comprising the following steps, which are substantially the same as those in Example 1, except that in step S1, 4-(bromomethyl)-1-methylbenzene (1.1 mol) is used as the benzyl halide to obtain a diquaternary ammonium salt JA-9 (0.46 mol) with a yield of 92%. In step S2, an aqueous solution (500 mL) containing 0.4 mol of the diquaternary ammonium salt JA-0 is added dropwise at 90° C. to finally obtain 56.2 g of parylene N powder (0.27 mol) with a yield of 68%.

[0050] Example 3

[0051] This embodiment provides a preparation method of a parylene series product (parylene M powder) and a parylene series product, and the reaction equation is as follows:

[0052] The specific steps include:

[0053] S1. 1-(Chloromethyl)-1,3,4-trimethylbenzene (1.1 mol) and N,N,N',N'-tetramethyldiaminomethane (0.5 mol) were added to ethanol (500 ml) in sequence, and the mixture was stirred at 40 ° C for 4 hours. After the reaction was completed, the solvent was removed under reduced pressure to obtain a crude solid product, which was slurried with methyl tert-butyl ether (200 mL) to obtain diquaternary ammonium salt JA-5 (0.44 mol) with a yield of 88%;

[0054] S2. A 51% aqueous solution of KOH (6.09 mol) (669 g), xylene (1000 mL), dimethyl sulfoxide (430 mL), and benzyltributylammonium chloride (0.004 mol) were added to a reaction flask. A 0.4 mol aqueous solution of diquaternary ammonium salt JA-5 (500 mL) was added dropwise at 100°C with stirring over a period of 4 hours. The reaction was then maintained at 100°C for 20 hours. The reaction mixture was allowed to stand for stratification. The upper xylene phase was removed, washed with water, and decolorized with activated carbon. The filtrate was concentrated by distillation to 750 mL, cooled, and crystallized to obtain white crystals. The mixture was then dried under vacuum at 50°C to obtain 58.2 g of parylene M powder (0.22 mol), with a yield of 55%.

[0055] The NMR characterization data are as follows: 1 H NMR (400MHz, CDCl3): δ2.24(s,12H,CH3), 2.73(m,4H,CH2), 3.16(m,4H,CH2)6.40(s,4H,ArH).

[0056] Example 4

[0057] This embodiment provides a preparation method of a parylene series product (parylene B powder) and a parylene series product, and the reaction equation is as follows:

[0058] The steps include:

[0059] S1. Add N,N,N',N'-tetramethyldiaminomethane (0.5 mol) to dichloromethane (300 ml), add dropwise 100 mL of a dichloromethane solution containing 0.5 mol of 4-(chloromethyl)-1-methylbenzene at 20°C, and stir to react for 3 hours. Then add dropwise 100 mL of a dichloromethane solution containing 0.5 mol of 2-bromo-4-(chloromethyl)-1-methylbenzene, and stir to react for 3 hours. Remove the solvent under reduced pressure to obtain a crude solid product, and slurry with methyl tert-butyl ether (200 mL) to obtain diquaternary ammonium salt JA-7 (0.42 mol) with a yield of 84%.

[0060] S2. A 51% aqueous solution of KOH (6.09 mol) (669 g), toluene (1000 mL), dimethyl sulfoxide (430 mL), and benzyltriphenylphosphonium chloride (0.004 mol) were added to a reaction flask. A 0.4 mol aqueous solution of diquaternary ammonium salt JA-7 (500 mL) was added dropwise with stirring at 100°C over a period of 4 hours. The reaction was then maintained at 100°C for 22 hours. The reaction mixture was allowed to stand for stratification. The upper xylene phase was removed, washed with water, and decolorized with activated carbon. The filtrate was concentrated by distillation to 500 mL, cooled, and crystallized to obtain white crystals. The mixture was then dried under vacuum at 50°C to obtain 54.6 g of parylene B powder (0.19 mol), with a yield of 48%.

[0061] The NMR characterization data are as follows: 1 H NMR (400MHz, CDCl3): δ2.76-2.88(m,8H),6.93(dd,1H,ArH),7.06-7.11(m,5H,ArH),7.17(d,1H,ArH).

[0062] Example 5

[0063] This embodiment provides a preparation method of a parylene series product (parylene C powder) and a parylene series product, and the reaction equation is as follows:

[0064] The specific steps include:

[0065] S1. 3-Chloro-4-methylbenzyl chloride (1.1 mol) and N,N,N',N'-tetramethyldiaminomethane (0.5 mol) were added to toluene (500 ml) in sequence, and the mixture was stirred at 50°C for 4 hours. After the reaction was completed, the solvent was removed under reduced pressure to obtain a crude solid. The crude solid was slurried with methyl tert-butyl ether (200 mL) to obtain diquaternary ammonium salt JA-2 (0.46 mol) with a yield of 93%;

[0066] S2. A 51% aqueous solution of KOH (6.09 mol) (669 g), xylene (1000 mL), dimethyl sulfoxide (430 mL), and tetrabutylammonium bromide (0.004 mol) were added to a reaction flask. An aqueous solution containing 0.4 mol of the diquaternary ammonium salt JA-2 (500 mL) was added dropwise with stirring at 90°C over a period of 4 hours. The reaction mixture was allowed to stand for 24 hours, and the upper xylene phase was removed, washed with water, and decolorized with activated carbon. The filtrate was concentrated by distillation to 300 mL, cooled, and crystallized to obtain white crystals. The mixture was then dried under vacuum at 50°C to obtain 63.8 g of parylene C powder (0.23 mol), with a yield of 58%.

[0067] The NMR characterization data are as follows: 1H NMR (400MHz, CDCl3): δ2.80-2.84(m,2H,CH2),2.95-2.99(m,2H,CH2),3.13-3.20(m,2 H,CH2), 3.51-3.57(m,2H,CH2), 6.31(d,2H,ArH), 6.47(d,2H,ArH), 7.06(dd,2H,ArH).

[0068] Example 6

[0069] This embodiment provides a preparation method of a parylene series product (parylene F powder) and a parylene series product, and the reaction equation is as follows:

[0070] The specific steps include:

[0071] S1. 1,2,4,5-tetrafluorobenzyl bromide (1.1 mol) and N,N,N',N'-tetramethyldiaminomethane (0.5 mol) were added to dichloromethane (500 ml) in sequence, and the mixture was stirred at 20°C for 5 hours. After the reaction was completed, the solvent was removed under reduced pressure to obtain a crude solid. The solid was slurried with methyl tert-butyl ether (200 mL) to obtain diquaternary ammonium salt JA-4 (0.46 mol) with a yield of 92%.

[0072] S2. A 51% aqueous solution of KOH (6.09 mol) (669 g), xylene (1000 mL), dimethyl sulfoxide (430 mL), and tetrabutylammonium bromide (0.004 mol) were added to a reaction flask. An aqueous solution containing 0.4 mol of the diquaternary ammonium salt JA-4 (500 mL) was added dropwise with stirring at 110°C over a period of 4 hours. The reaction was then maintained at 110°C for 18 hours. The reaction solution was allowed to stand and separate. The upper xylene phase was removed, washed with water, and decolorized with activated carbon. The filtrate was concentrated by distillation to 350 mL, cooled, and crystallized to obtain white crystals. The product was then dried under vacuum at 50°C to obtain 101.4 g of parylene F powder (0.29 mol), with a yield of 73%.

[0073] The NMR characterization data are as follows: 1 H NMR (400MHz, CDCl3): δ3.30 (s, 8H, CH2).

[0074] Example 7

[0075] This embodiment provides a preparation method of a parylene series product (parylene D powder) and a parylene series product, and the reaction equation is as follows:

[0076] The steps include:

[0077] S1. 2,4-dichloro-4-methylbenzyl chloride (1.1 mol) and N,N,N',N'-tetramethyldiaminomethane (0.5 mol) were added to toluene (500 ml) in sequence, and the mixture was stirred at 50°C for 5 hours. After the reaction was completed, the solvent was removed under reduced pressure to obtain a crude solid. The crude solid was slurried with methyl tert-butyl ether (200 mL) to obtain diquaternary ammonium salt JA-3 (0.45 mol) with a yield of 90%;

[0078] S2. A 51% aqueous solution of KOH (6.09 mol) (669 g), xylene (1000 mL), dimethyl sulfoxide (430 mL), and benzyltributylammonium bromide (0.004 mol) were added to a reaction flask. An aqueous solution containing 0.4 mol of diquaternary ammonium salt JA-3 (500 mL) was added dropwise with stirring at 90°C for 4 hours. The reaction mixture was maintained at 90°C for 24 hours. The reaction mixture was allowed to stand and separate into layers. The upper xylene phase was removed, washed with water, and decolorized with activated carbon. The filtrate was concentrated by distillation to 300 mL and cooled for crystallization to obtain white crystals. The mixture was dried under vacuum at 50°C to obtain 96.9 g of parylene D powder (0.28 mol), with a yield of 70%.

[0079] The NMR characterization data are as follows: 1 H NMR (400MHz, CDCl3): δ2.89(m,4H,ArCH2), 3.28(m,4H,ArCH2), 6.95(s,4H,ArH).

[0080] Example 8

[0081] This embodiment provides a preparation method of a parylene series product (parylene P-5 powder) and a parylene series product, and the reaction equation is as follows:

[0082] The steps include:

[0083] S1. 2,4-dibromo-4-methylbenzyl bromide (1.1 mol) and N,N,N',N'-tetramethyldiaminomethane (0.5 mol) were added to dichloromethane (500 ml) in sequence, and the mixture was stirred at 20°C for 5 hours. After the reaction was completed, the solvent was removed under reduced pressure to obtain a crude solid. The crude solid was slurried with methyl tert-butyl ether (200 mL) to obtain diquaternary ammonium salt JA-18 (0.47 mol) with a yield of 94%;

[0084] S2. A 51% aqueous solution of KOH (6.09 mol) (669 g), toluene (1000 mL), dimethyl sulfoxide (430 mL), and benzyltributylammonium bromide (0.004 mol) were added to a reaction flask. An aqueous solution containing 0.4 mol of the diquaternary ammonium salt JA-18 (500 mL) was added dropwise with stirring at 90°C over a period of 4 hours. The reaction mixture was maintained at 90°C for 28 hours. The reaction mixture was allowed to stand for stratification. The upper xylene phase was removed, washed with water, and decolorized with activated carbon. The filtrate was concentrated by distillation to 300 mL and cooled for crystallization to obtain white crystals. The mixture was then dried under vacuum at 50°C to obtain 152 g of parylene P-5 powder (0.29 mol), with a yield of 72.5%.

[0085] The NMR characterization data are as follows: 1 H NMR (400MHz, CDCl3): δ7.20(s,4H,Ar-H), 3.29-3.18(m,4H,CH2), 3.04-2.93(m,4H,CH2).

[0086] Example 9

[0087] This embodiment provides a preparation method of a parylene series product (parylene E powder) and a parylene series product, and the reaction equation is as follows:

[0088] The specific steps include:

[0089] S1. 2-Ethyl-4-methylbenzyl bromide (1.1 mol) and N,N,N',N'-tetramethyldiaminomethane (0.5 mol) were added sequentially to tetrahydrofuran (500 ml) and stirred at 40°C for 3 hours. After the reaction was completed, the solvent was removed under reduced pressure to obtain a crude solid. The solid was slurried with methyl tert-butyl ether (200 mL) to obtain diquaternary ammonium salt JA-12 (0.46 mol) in a yield of 92%.

[0090] S2. A 51% aqueous solution of KOH (6.09 mol) (669 g), xylene (1000 mL), dimethyl sulfoxide (430 mL), and benzyltributylammonium bromide (0.004 mol) were added to a reaction flask. A 0.4 mol aqueous solution of diquaternary ammonium salt JA-12 (500 mL) was added dropwise with stirring at 90°C over a period of 4 hours. The reaction was maintained at 90°C for 30 hours. The reaction solution was allowed to stand and separate. The upper xylene phase was removed, washed with water, and decolorized with activated carbon. The filtrate was concentrated by distillation to 300 mL, cooled, and crystallized to obtain white crystals. The mixture was then dried under vacuum at 50°C to obtain 66 g of parylene E powder (0.25 mol), with a yield of 62.5%.

[0091] The NMR characterization data are as follows: 1H NMR (400MHz, CDCl3): δ6.60-6.56(m,2H,ArH),6.31-6.29(m,2H,ArH),6.14(bs,2H,ArH),3.38-3.30(m,2H ,CH2),3.06-2.96(m,4H,CH2),2.83-2.72(m,2H,CH2),2.32-2.22(m,4H,CH2-CH3),1.18-1.38(m,6H,CH3).

[0092] Example 10

[0093] This embodiment provides a preparation method of a parylene series product (parylene P-3 powder) and a parylene series product, and the reaction equation is as follows:

[0094] The specific steps include:

[0095] S1. 3-Bromo-4-methylbenzyl bromide (1.1 mol) and N,N,N',N'-tetramethyldiaminomethane (0.5 mol) were added to dichloromethane (500 ml) in sequence, and the reaction was stirred at 20 ° C for 5 hours. After the reaction was completed, the solvent was removed under reduced pressure to obtain a crude solid product, which was slurried with methyl tert-butyl ether (200 mL) to obtain diquaternary ammonium salt JA-6 (0.45 mol) with a yield of 91%;

[0096] S2. A 51% aqueous solution of KOH (6.09 mol) (669 g), xylene (1000 mL), dimethyl sulfoxide (430 mL), and tetrabutylammonium bromide (0.004 mol) were added to a reaction flask. A 0.4 mol aqueous solution of diquaternary ammonium salt JA-6 (500 mL) was added dropwise with stirring at 90°C for 4 hours. The reaction mixture was maintained at 90°C for 24 hours. The reaction mixture was allowed to stand and separate. The upper xylene phase was removed, washed with water, and decolorized with activated carbon. The filtrate was concentrated by distillation to 300 mL and cooled for crystallization to obtain white crystals. The mixture was then dried under vacuum at 50°C to obtain 102.5 g of parylene P-3 powder (0.28 mol), with a yield of 70%.

[0097] The NMR characterization data are as follows: 1 H NMR (400MHz, CDCl3): δ=7.17(d,2H), 6.60(d,2H), 6.47(dd,2H), 3.36-3.25(m,2H), 3.11-3.01(m,4H), 2.93-2.83(m,2H).

[0098] Example 11

[0099] This embodiment provides a preparation method of a parylene series product (parylene P-8 powder) and a parylene series product, and the reaction equation is as follows:

[0100] The specific steps include:

[0101] S1. 3-Trifluoromethyl-4-methylbenzyl bromide (0.5 mol) and N,N,N',N'-tetramethyldiaminomethane (0.5 mol) were added to dichloromethane (500 ml) in sequence, and the mixture was stirred at 20 ° C for 3 hours. Then, 100 mL of a dichloromethane solution containing 0.5 mol of 4-(bromomethyl)-1-methylbenzene was added dropwise, and the mixture was stirred for 3 hours. After the reaction was completed, the solvent was removed under reduced pressure to obtain a crude solid product, which was slurried with methyl tert-butyl ether (200 mL) to obtain diquaternary ammonium salt JA-11 (0.45 mol) with a yield of 91%;

[0102] S2. A 51% aqueous solution of KOH (6.09 mol) (669 g), xylene (1000 mL), dimethyl sulfoxide (430 mL), and tetrabutylammonium bromide (0.004 mol) were added to a reaction flask. A 0.4 mol aqueous solution of diquaternary ammonium salt JA-11 (500 mL) was added dropwise with stirring at 90°C over a period of 4 hours. The reaction mixture was allowed to stand for 24 hours, and the upper xylene phase was removed, washed with water, and decolorized with activated carbon. The filtrate was concentrated by distillation to 300 mL, cooled, and crystallized to obtain white crystals. The mixture was then dried under vacuum at 50°C to obtain 71.84 g of parylene P-8 powder (0.26 mol), with a yield of 65%.

[0103] The NMR characterization data are as follows: 1 H NMR (400MHz, CDCl3): δ = 2.90-3.30 (m, 6H, CH2), 3.41-3.57 (m, 2H, CH2), 6.36-6.94 (m, 7H, ArH).

[0104] The applicant states that while the above-described embodiments illustrate the method for preparing a parylene series product, the present invention is not limited to these embodiments. This does not necessarily mean that the present invention must rely on these embodiments in order to be implemented. Those skilled in the art will appreciate that any improvements to the present invention, equivalent substitutions for raw materials, additions of auxiliary ingredients, and selection of specific methods for the preparation of the present invention are all within the scope of protection and disclosure of the present invention.

Claims

1. A method for preparing a series of parylene products, characterized in that: The steps include: S1. Compound 1 and compound 2 react with N,N,N',N'-tetramethyldiaminomethane to obtain a diquaternary ammonium salt; S2. The diquaternary ammonium salt and the catalyst undergo elimination reaction under alkaline conditions to obtain a series of parylene products of the general formula shown in Formula Ⅰ; The structural formulas of compound 1, compound 2 and diquaternary ammonium salt are respectively represented by the general formulas shown in formula II, formula III and formula IV: Wherein, R1, R2, R3, R4, R5, R6, R7, and R8 are each independently selected from a hydrogen atom, a halogen, an amino group, a nitro group, an ester group, an aldehyde group, a methoxy group, an ethoxy group, a cyano group, a trifluoromethyl group, an ethynyl group, a vinyl group, and a saturated alkyl group; and X and Y are each independently selected from a fluorine, a chlorine, a bromine, or an iodine atom.

2. The preparation method according to claim 1, characterized in that: In step S2, after the elimination reaction, a quinone dimethane intermediate state of the general formula shown in Formula V is formed: The quinone dimethane intermediate undergoes a ring-closing reaction to form a series of parylene products of the general formula shown in Formula I, wherein m is at least one of 1, 2, 3, and 4, and n is at least one of 5, 6, 7, and 8.

3. The preparation method according to claim 1 or 2, characterized in that: In step S2, the catalyst is a quaternary ammonium salt and / or a quaternary phosphonium salt; Preferably, the catalyst includes at least one of triphenylmethylphosphonium bromide, tetraphenylphosphonium bromide, tetrabutylphosphonium hydroxide, benzyltriphenylphosphonium chloride, hexadecyltributylphosphonium chloride, hexadecyltrihexylphosphonium chloride, allyltriphenylphosphonium chloride, pentyltributylphosphonium chloride, benzyltributylphosphonium chloride, propyltriphenylphosphonium chloride and other quaternary phosphonium salts, benzyltributylammonium chloride, tetrabutylammonium bromide and tetrabutylammonium chloride.

4. The preparation method according to any one of claims 1 to 3, characterized in that: In step S1, compound 1 and compound 2 are independently selected from at least one of the following structural formulas:

5. The preparation method according to any one of claims 1 to 4, characterized in that: The Parylene series products are selected from at least one of the following structural formulas:

6. The preparation method according to any one of claims 1 to 5, characterized in that: Step S2 is carried out under alkaline conditions, and the base selected is a strong inorganic base; Preferably, the inorganic strong base is one or more selected from NaOH, KOH, LiOH, RbOH, CsOH, GrOH, Ca(OH)2, Sr(OH)2, Ba(OH)2 and Ra(OH)2.

7. The preparation method according to any one of claims 1 to 6, characterized in that: In step S1, the molar ratio of the compound 1 to the compound 2 is 1:1, and the molar ratio of the compound 1 to the N,N,N',N'-tetramethyldiaminomethane is (0.9-1):1; Preferably, the reaction temperature is 10-50°C and the reaction time is 2-5h.

8. The preparation method according to any one of claims 1 to 7, characterized in that: In step S2, the molar ratio of the total feed of the compound 1 and the compound 2 to the feed of the catalyst is 100:(0.1-1); Preferably, the temperature of the elimination reaction is 90-120° C. and the time is 18-30 hours.

9. The preparation method according to any one of claims 1 to 8, characterized in that: Step S1 also includes a first solvent, which is one or more selected from dichloromethane, methanol, ethanol, isopropanol, tetrahydrofuran, toluene, 1,4-dioxane, and N,N-dimethylformamide; step S2 also includes a second solvent with a boiling point greater than 85°C, which is at least two selected from xylene, dimethyl sulfoxide, toluene, anisole, 1,4-dioxane, mesitylene, and chlorobenzene.

10. A parylene series product, characterized in that: Prepared by the preparation method according to any one of claims 1 to 9, the parylene series product is selected from at least one of the following structural formulas:

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