A kind of synthetic method of 3-bromo-1-phenylnaphthalene

Abstract

The present application relates to the field of chemical synthesis, and specifically discloses a method for synthesizing 3-bromo-1-phenylnaphthalene. The method comprises the following steps: preparing a bromobenzene Grignard reagent using bromobenzene as a raw material; 1-tetralone reacts with a bromobenzene Grignard reagent to generate a mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene; a mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene undergoes a bromination reaction with N-bromosuccinimide in the presence of an initiator to generate 3-bromo-1-phenylnaphthalene. The method for synthesizing 3-bromo-1-phenylnaphthalene of the present application has the advantages of low cost, short route, simple operation, high product yield and purity.

Description

Technical Field

[0001] The present invention relates to the field of chemical synthesis, and more specifically, to a method for synthesizing 3-bromo-1-phenylnaphthalene. Background Art

[0002] 3-Bromo-1-phenylnaphthalene is an intermediate for preparing liquid crystal display materials. Organic light-emitting diode (OLED) is a device that uses a multilayer organic thin film structure to generate electroluminescence. It can be divided into small molecule OLED and polymer OLED according to the luminescent material. 3-Bromo-1-phenylnaphthalene is one of the important raw materials for preparing small molecule OLED. Because 3-Bromo-1-phenylnaphthalene has the characteristics of high hole and high electron mobility, it is an ideal OLED main material.

[0003] At present, there is a method for synthesizing 3-bromo-1-phenylnaphthalene: 1-phenyl-4-naphthaleneamine is brominated with N-bromosuccinimide to generate 1-phenyl-3-bromo-4-naphthaleneamine, and 1-phenyl-3-bromo-4-naphthaleneamine is then diazotized to obtain 3-bromo-1-phenylnaphthalene. The 1-phenyl-4-naphthaleneamine in the above-mentioned synthesis method is obtained by coupling 1-bromo-4-naphthaleneamine with palladium catalysis, or by nitrification of 1-phenylnaphthalene and then reduction. Both methods are very expensive, making the raw materials very expensive. In addition, the process of diazotization reduction in the second step is dangerous and polluting, with low yield and high cost.

[0004] Therefore, based on the current status of the 3-bromo-1-phenylnaphthalene synthesis method, it is of great significance to study a 3-bromo-1-phenylnaphthalene synthesis method with low cost, simple operation, high yield and high purity. Summary of the invention

[0005] In order to reduce the preparation cost and operation difficulty of 1-bromo-4-phenylnaphthalene and effectively improve the yield and purity of the product, the present application provides a method for synthesizing 3-bromo-1-phenylnaphthalene.

[0006] A method for synthesizing 3-bromo-1-phenylnaphthalene comprises the following steps:

[0007] Bromobenzene was used as a raw material to prepare the bromobenzene Grignard reagent;

[0008] 1-Tetralone reacts with bromobenzene Grignard reagent to produce a mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene;

[0009] A mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene undergoes bromination reaction with N-bromosuccinimide in the presence of an initiator to generate 3-bromo-1-phenylnaphthalene.

[0010] By adopting the above technical scheme, 1-tetralone reacts with bromobenzene Grignard reagent. After a period of reaction, the spot plate test and gas chromatography-mass spectrometry test results show that there are 1-phenyl-1-hydroxytetralin and part of the unreacted 1-tetralone in the system, and part of the 1-phenyl-1-hydroxytetralin has been dehydrated to form 1-phenyl-3,4-dihydronaphthalene. It can be seen that the intermediate product obtained after the reaction is a mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene. Then, the intermediate product undergoes a bromination reaction with N-bromosuccinimide in the presence of an initiator, and finally 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene react to form 3-bromo-1-phenylnaphthalene. The synthesis method of the present application has the advantages of low cost, short route, simple operation, high product yield and purity. The yield of the final product 3-bromo-1-phenylnaphthalene can reach 69.3-74.9%, and the purity can reach 97.9-98.6%.

[0011] Preferably, the molar ratio of bromobenzene to 1-tetralone is (1.125-1.250):1.

[0012] Preferably, the molar ratio of bromobenzene to 1-tetralone is 1.250:1.

[0013] By adopting the above technical scheme, in the synthesis process of 3-bromo-1-phenylnaphthalene, when the molar ratio of bromobenzene to 1-tetralone is 1.250:1, the yield of the mixture of the intermediate products 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene is relatively high, which can reach 91.1%; and the yield and purity of the final product 3-bromo-1-phenylnaphthalene are also relatively good, with the yield reaching 74.2% and the purity reaching 98.6%.

[0014] Preferably, the reaction temperature of 1-tetralone and bromobenzene Grignard reagent is not higher than 60°C.

[0015] By adopting the above technical scheme, the correct progress of the synthesis reaction is guaranteed, thereby successfully synthesizing 3-bromo-1-phenylnaphthalene.

[0016] Preferably, the solvent of the bromination reaction is chloroform, and the weight ratio of the mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene to chloroform in the bromination reaction is 1:(9-11).

[0017] Preferably, in the bromination reaction, the molar ratio of the mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene to N-bromosuccinimide is 1:2.2.

[0018] Preferably, the initiator of the bromination reaction is azobisisobutyronitrile, and the weight ratio of the mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene to azobisisobutyronitrile in the bromination reaction is 1:(0.045-0.073).

[0019] Preferably, the bromination reaction time is 15 to 20 hours.

[0020] In summary, this application has at least the following beneficial effects:

[0021] The synthesis method of the present application has easy-to-obtain raw materials, low cost, short route, simple operation, and mild reaction process. 3-bromo-1-phenylnaphthalene can be successfully synthesized with a yield of 69.3-74.9% and a purity of 97.9-98.6%. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the hydrogen nuclear magnetic resonance spectrum of 3-bromo-1-phenylnaphthalene in Example 1 of the present application. DETAILED DESCRIPTION

[0023] The present application is further described in detail below with reference to the accompanying drawings and embodiments.

[0024] Unless otherwise specified, the raw materials used in the embodiments of the present application are commercially available. Example

[0025] Example 1

[0026] A method for synthesizing 3-bromo-1-phenylnaphthalene, comprising the following steps:

[0027] S1, add 50mL of tetrahydrofuran and 8g (50mmol) of bromobenzene to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, add 12g (500mmol) of magnesium chips, and then add 1g of dibromoethane. After initiation, keep reflux, and dropwise add a tetrahydrofuran solution of bromobenzene under reflux, wherein the tetrahydrofuran solution of bromobenzene is obtained by dissolving 71g (450mmol) of bromobenzene in 200ml of tetrahydrofuran. After the dropwise addition is completed, continue to reflux for 2 hours to obtain a bromobenzene Grignard reagent;

[0028] S2, the obtained product of S1 is cooled to 50°C, 58.5g (400mmol) of 1-tetralone is added dropwise, the temperature is controlled not to exceed 60°C, and refluxed for 2 hours after the addition is completed (the spot plate test (using petroleum ether as the developing solvent) and the gas chromatography-mass spectrometry test results show that a small amount of 1-tetralone has not reacted, and some 1-phenyl-1-hydroxytetralin has been dehydrated to form 1-phenyl-3,4-dihydronaphthalene), the obtained product is cooled to 5°C with ice water, 10% mass concentration of dilute sulfuric acid is added dropwise to pH=5, and the temperature is maintained at no more than 35°C. At this time, the unreacted bromobenzene Grignard reagent is decomposed into benzene and magnesium bromide, the liquids are separated, the aqueous phase is extracted with ethyl acetate, the organic phases are combined, and the ethyl acetate and benzene are removed by spin drying to obtain 81.6g of the intermediate product (a mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene), and the intermediate product yield is 91.1%;

[0029] S3, add 50mL of chloroform and 19.6g (110mmol) of N-bromosuccinimide to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, heat to reflux, and dropwise add a chloroform solution of the intermediate product, which is obtained by dissolving 11g (about 50mmol) of the intermediate product obtained from S2 and 0.5g of azobisisobutyronitrile in 50mL of chloroform. After the dropwise addition is completed, The reaction was continued under reflux for 16 h. After the reaction was completed, the mixture was washed once with 100 mL of pure water, separated, and then washed once with 100 mL of saturated brine, separated, and the organic phase was dried over 10 g of sodium sulfate, filtered, and the filtrate was spin-dried to obtain 14 g of crude 3-bromo-1-phenylnaphthalene. The crude 3-bromo-1-phenylnaphthalene was distilled under reduced pressure and slurried with petroleum ether and dried to obtain 10.5 g of white powder (3-bromo-1-phenylnaphthalene), with a yield of 74.2%, a purity of 98.6%, a melting point of 65.8 ° C, and a hydrogen spectrum as shown in FIG. Figure 1 shown.

[0030] Example 2

[0031] A method for synthesizing 3-bromo-1-phenylnaphthalene, comprising the following steps:

[0032] S1, add 50mL of tetrahydrofuran and 8g (50mmol) of bromobenzene to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, add 10.8g (450mmol) of magnesium chips, and then add 1g of dibromoethane. After initiation, keep reflux, and add a tetrahydrofuran solution of bromobenzene dropwise under reflux, wherein the tetrahydrofuran solution of bromobenzene is obtained by dissolving 62.8g (400mmol) of bromobenzene in 200ml of tetrahydrofuran. After the addition is completed, continue to reflux for 2 hours to obtain a bromobenzene Grignard reagent;

[0033] S2, the obtained product of S1 is cooled to 50°C, 58.5g (400mmol) of 1-tetralone is added dropwise, the temperature is controlled not to exceed 60°C, and after the addition is completed, reflux is performed for 2 hours (the results of the spot plate test (using petroleum ether as the developing solvent) and the gas chromatography-mass spectrometry test show that a small amount of 1-tetralone has not reacted, and a part of 1-phenyl-1-hydroxytetralin has been dehydrated to form 1-phenyl-3,4-dihydronaphthalene), the obtained product is cooled to 5°C with ice water, 10% mass concentration of dilute sulfuric acid is added dropwise to pH=5, and the temperature is maintained at not higher than 35°C. At this time, the unreacted bromobenzene Grignard reagent is decomposed into benzene and magnesium bromide, the liquids are separated, the aqueous phase is extracted with ethyl acetate, the organic phases are combined, and the ethyl acetate and benzene are removed by spin drying to obtain 81.2g of the intermediate product (a mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene), and the intermediate product yield is 90.6%;

[0034] S3, add 50mL of chloroform and 19.6g (110mmol) of N-bromosuccinimide to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, heat to reflux, and dropwise add a chloroform solution of the intermediate product, which is obtained by dissolving 11g (about 50mmol) of the intermediate product obtained from S2 and 0.5g of azobisisobutyronitrile in 50mL of chloroform. After that, the reflux reaction was continued for 16 hours. After the reaction was completed, it was washed once with 100 mL of pure water, separated, and then washed once with 100 mL of saturated brine, separated, and the organic phase was dried with 10 g of sodium sulfate, filtered, and the filtrate was spin-dried to obtain a crude 3-bromo-1-phenylnaphthalene. The crude 3-bromo-1-phenylnaphthalene was distilled under reduced pressure and then slurried with petroleum ether and dried to obtain 10.3 g of white powder (3-bromo-1-phenylnaphthalene) with a yield of 72.8%, a purity of 98.2%, and a melting point of 65.3°C.

[0035] Example 3

[0036] A method for synthesizing 3-bromo-1-phenylnaphthalene, comprising the following steps:

[0037] S1, add 50mL of tetrahydrofuran and 8g (50mmol) of bromobenzene to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, add 12g (500mmol) of magnesium chips, and then add 1g of dibromoethane. After initiation, keep reflux, and dropwise add a tetrahydrofuran solution of bromobenzene under reflux, wherein the tetrahydrofuran solution of bromobenzene is obtained by dissolving 55g (350mmol) of bromobenzene in 200ml of tetrahydrofuran. After the dropwise addition is completed, continue to reflux for 2 hours to obtain a bromobenzene Grignard reagent;

[0038] S2, the obtained product of S1 is cooled to 50°C, 58.5g (400mmol) of 1-tetralone is added dropwise, the temperature is controlled not to exceed 60°C, and refluxed for 2 hours after the addition is completed (the spot plate test (using petroleum ether as the developing solvent) and the gas chromatography-mass spectrometry test results show that a small amount of 1-tetralone has not reacted, and some 1-phenyl-1-hydroxytetralin has been dehydrated to form 1-phenyl-3,4-dihydronaphthalene), the obtained product is cooled to 5°C with ice water, 10% mass concentration of dilute sulfuric acid is added dropwise to pH=5, and the temperature is maintained at no more than 35°C. At this time, the unreacted bromobenzene Grignard reagent is decomposed into benzene and magnesium bromide, the liquids are separated, the aqueous phase is extracted with ethyl acetate, the organic phases are combined, and the ethyl acetate and benzene are removed by spin drying to obtain 79.4g of the intermediate product (a mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene), and the intermediate product yield is 88.6%;

[0039] S3, add 50mL of chloroform and 19.6g (110mmol) of N-bromosuccinimide to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, heat to reflux, and dropwise add a chloroform solution of the intermediate product, which is obtained by dissolving 11g (about 50mmol) of the intermediate product obtained from S2 and 0.5g of azobisisobutyronitrile in 50mL of chloroform. After that, the reflux reaction was continued for 16 hours. After the reaction was completed, it was washed once with 100 mL of pure water, separated, and then washed once with 100 mL of saturated brine, separated, and the organic phase was dried with 10 g of sodium sulfate, filtered, and the filtrate was spin-dried to obtain a crude 3-bromo-1-phenylnaphthalene. The crude 3-bromo-1-phenylnaphthalene was distilled under reduced pressure and then slurried with petroleum ether and dried to obtain 9.8 g of white powder (3-bromo-1-phenylnaphthalene), with a yield of 69.3%, a purity of 97.9%, and a melting point of 65.0°C.

[0040] Example 4

[0041] A method for synthesizing 3-bromo-1-phenylnaphthalene, comprising the following steps:

[0042] S1, take 11 g of the intermediate product obtained in step S2 of Example 1 for use in this example;

[0043] S2, add 60 mL of chloroform and 19.6 g (110 mmol) of N-bromosuccinimide to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, heat to reflux, and dropwise add a chloroform solution of the intermediate product, which is obtained by dissolving 11 g (about 50 mmol) of the intermediate product and 0.5 g of azobisisobutyronitrile in 60 mL of chloroform. After the dropwise addition is completed, The reaction was continued at reflux for 16 h. After the reaction was completed, the mixture was washed once with 100 mL of pure water, separated, and then washed once with 100 mL of saturated brine, separated, and the organic phase was dried over 10 g of sodium sulfate, filtered, and the filtrate was spin-dried to obtain a crude 3-bromo-1-phenylnaphthalene. The crude 3-bromo-1-phenylnaphthalene was distilled under reduced pressure and then slurried with petroleum ether and dried to obtain 10.4 g of a white powder (3-bromo-1-phenylnaphthalene) with a yield of 73.5%, a purity of 98.3%, and a melting point of 65.4°C.

[0044] Example 5

[0045] A method for synthesizing 3-bromo-1-phenylnaphthalene, comprising the following steps:

[0046] S1, take 11 g of the intermediate product obtained in step S2 of Example 1 for use in this example;

[0047] S2, add 50mL of chloroform and 19.6g (110mmol) of N-bromosuccinimide to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, heat to reflux, and dropwise add a chloroform solution of the intermediate product, which is obtained by dissolving 11g (about 50mmol) of the intermediate product and 0.6g of azobisisobutyronitrile in 50mL of chloroform. After the dropwise addition is completed, The reaction was continued under reflux for 16 h. After the reaction was completed, the mixture was washed once with 100 mL of pure water, separated, and then washed once with 100 mL of saturated brine, separated. The organic phase was dried over 10 g of sodium sulfate, filtered, and the filtrate was spin-dried to obtain a crude 3-bromo-1-phenylnaphthalene. The crude 3-bromo-1-phenylnaphthalene was distilled under reduced pressure and then slurried with petroleum ether and dried to obtain 10.6 g of a white powder (3-bromo-1-phenylnaphthalene) with a yield of 74.9%, a purity of 98.3%, and a melting point of 65.5 °C.

[0048] Example 6

[0049] A method for synthesizing 3-bromo-1-phenylnaphthalene, comprising the following steps:

[0050] S1, take 11 g of the intermediate product obtained in step S2 of Example 1 for use in this example;

[0051] S2, add 50mL of chloroform and 19.6g (110mmol) of N-bromosuccinimide to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, heat to reflux, and dropwise add a chloroform solution of the intermediate product, which is obtained by dissolving 11g (about 50mmol) of the intermediate product and 0.8g of azobisisobutyronitrile in 50mL of chloroform. After the dropwise addition is completed, The reaction was continued at reflux for 16 h. After the reaction was completed, the mixture was washed once with 100 mL of pure water, separated, and then washed once with 100 mL of saturated brine, separated, and the organic phase was dried over 10 g of sodium sulfate, filtered, and the filtrate was spin-dried to obtain a crude 3-bromo-1-phenylnaphthalene. The crude 3-bromo-1-phenylnaphthalene was distilled under reduced pressure and then slurried with petroleum ether and dried to obtain 10.4 g of a white powder (3-bromo-1-phenylnaphthalene) with a yield of 73.5%, a purity of 98.4%, and a melting point of 65.6°C.

[0052] Example 7

[0053] A method for synthesizing 3-bromo-1-phenylnaphthalene, comprising the following steps:

[0054] S1, take 11 g of the intermediate product obtained in step S2 of Example 1 for use in this example;

[0055] S2, add 50mL of chloroform and 19.6g (110mmol) of N-bromosuccinimide to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, heat to reflux, and dropwise add a chloroform solution of the intermediate product, which is obtained by dissolving 11g (about 50mmol) of the intermediate product obtained by S2 and 0.5g of azobisisobutyronitrile in 50mL of chloroform. After that, the reflux reaction was continued for 15 hours. After the reaction was completed, it was washed once with 100 mL of pure water, separated, and then washed once with 100 mL of saturated brine, separated, and the organic phase was dried with 10 g of sodium sulfate, filtered, and the filtrate was spin-dried to obtain a crude 3-bromo-1-phenylnaphthalene. The crude 3-bromo-1-phenylnaphthalene was distilled under reduced pressure and then slurried with petroleum ether and dried to obtain 10.2 g of white powder (3-bromo-1-phenylnaphthalene) with a yield of 72.1%, a purity of 98.1%, and a melting point of 65.1°C.

[0056] Example 8

[0057] A method for synthesizing 3-bromo-1-phenylnaphthalene, comprising the following steps:

[0058] S1, take 11 g of the intermediate product obtained in step S2 of Example 1 for use in this example;

[0059] S2, add 50 mL of chloroform and 19.6 g (110 mmol) of N-bromosuccinimide to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, heat to reflux, and dropwise add a chloroform solution of the intermediate product, which is obtained by dissolving 11 g (about 50 mmol) of the intermediate product obtained by S2 and 0.5 g of azobisisobutyronitrile in 50 mL of chloroform, dropwise After the addition was completed, the reflux reaction was continued for 20 hours. After the reaction was completed, it was washed once with 100 mL of pure water, separated, and then washed once with 100 mL of saturated brine, separated, and the organic phase was dried with 10 g of sodium sulfate, filtered, and the filtrate was spin-dried to obtain a crude 3-bromo-1-phenylnaphthalene. The crude 3-bromo-1-phenylnaphthalene was distilled under reduced pressure and then slurried with petroleum ether and dried to obtain a white powder (3-bromo-1-phenylnaphthalene) with a yield of 72.8%, a purity of 98.1%, and a melting point of 65.0°C.

[0060] Example 9

[0061] A method for synthesizing 3-bromo-1-phenylnaphthalene, comprising the following steps:

[0062] S1, take 11 g of the intermediate product obtained in step S2 of Example 1 for use in this example;

[0063] S2, add 50mL of chloroform and 17.8g (100mmol) of N-bromosuccinimide to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, heat to reflux, and dropwise add a chloroform solution of the intermediate product, which is obtained by dissolving 11g (about 50mmol) of the intermediate product obtained by S2 and 0.5g of azobisisobutyronitrile in 50mL of chloroform. After the dropwise addition is completed, The reflux reaction was continued for 16 hours. After the reaction was completed, the mixture was washed once with 100 mL of pure water, separated, and then washed once with 100 mL of saturated brine, separated, and the organic phase was dried over 10 g of sodium sulfate, filtered, and the filtrate was spin-dried to obtain 14 g of crude 3-bromo-1-phenylnaphthalene. The crude 3-bromo-1-phenylnaphthalene was distilled under reduced pressure and then slurried with petroleum ether and dried to obtain 10.2 g of white powder (3-bromo-1-phenylnaphthalene), with a yield of 72.1%, a purity of 98.2%, and a melting point of 65.3°C.

[0064] Example 10

[0065] A method for synthesizing 3-bromo-1-phenylnaphthalene, comprising the following steps:

[0066] S1, take 11 g of the intermediate product obtained in step S2 of Example 1 for use in this example;

[0067] S2, add 50mL of chloroform and 21.4g (120mmol) of N-bromosuccinimide to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, heat to reflux, and dropwise add a chloroform solution of the intermediate product, which is obtained by dissolving 11g (about 50mmol) of the intermediate product obtained by S2 and 0.5g of azobisisobutyronitrile in 50mL of chloroform. After the dropwise addition is completed, The reflux reaction was continued for 16 hours. After the reaction was completed, the mixture was washed once with 100 mL of pure water, separated, and then washed once with 100 mL of saturated brine, separated, and the organic phase was dried over 10 g of sodium sulfate, filtered, and the filtrate was spin-dried to obtain 14 g of crude 3-bromo-1-phenylnaphthalene. The crude 3-bromo-1-phenylnaphthalene was distilled under reduced pressure and then slurried with petroleum ether and dried to obtain 10.3 g of white powder (3-bromo-1-phenylnaphthalene), with a yield of 72.8%, a purity of 98.4%, and a melting point of 65.7°C.

[0068] Embodiment 11

[0069] A method for synthesizing 3-bromo-1-phenylnaphthalene, comprising the following steps:

[0070] S1, add 50mL of tetrahydrofuran and 8g (50mmol) of bromobenzene to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, add 12g (500mmol) of magnesium chips, and then add 1g of dibromoethane. After initiation, keep reflux, and dropwise add a tetrahydrofuran solution of bromobenzene under reflux, wherein the tetrahydrofuran solution of bromobenzene is obtained by dissolving 71g (450mmol) of bromobenzene in 200ml of tetrahydrofuran. After the dropwise addition is completed, continue to reflux for 2 hours to obtain a bromobenzene Grignard reagent;

[0071] S2, the obtained product of S1 is cooled to 50°C, 58.5g (400mmol) of 1-tetralone is added dropwise, the temperature is controlled not to exceed 70°C, and refluxed for 2 hours after the addition is completed (the spot plate test (using petroleum ether as the developing solvent) and the gas chromatography-mass spectrometry test results show that a small amount of 1-tetralone has not reacted, and some 1-phenyl-1-hydroxytetralin has been dehydrated to form 1-phenyl-3,4-dihydronaphthalene), the obtained product is cooled to 5°C with ice water, 10% mass concentration of dilute sulfuric acid is added dropwise to pH=5, and the temperature is maintained at no more than 35°C. At this time, the unreacted bromobenzene Grignard reagent is decomposed into benzene and magnesium bromide, the liquids are separated, the aqueous phase is extracted with ethyl acetate, the organic phases are combined, and the ethyl acetate and benzene are removed by spin drying to obtain 81.0g of the intermediate product (a mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene), and the intermediate product yield is 90.4%;

[0072] S3, add 50mL of chloroform and 19.6g (110mmol) of N-bromosuccinimide to a four-necked flask equipped with a nitrogen conduit, a thermometer, a stirrer, a dropping device and a reflux device, introduce nitrogen and start stirring, heat to reflux, and dropwise add a chloroform solution of the intermediate product, which is obtained by dissolving 11g (about 50mmol) of the intermediate product obtained from S2 and 0.5g of azobisisobutyronitrile in 50mL of chloroform. After the dropwise addition is completed, The reflux reaction was continued for 16 hours. After the reaction was completed, the mixture was washed once with 100 mL of pure water, separated, and then washed once with 100 mL of saturated brine, separated, and the organic phase was dried over 10 g of sodium sulfate, filtered, and the filtrate was spin-dried to obtain 14 g of crude 3-bromo-1-phenylnaphthalene. The crude 3-bromo-1-phenylnaphthalene was distilled under reduced pressure and then slurried with petroleum ether and dried to obtain 10.0 g of white powder (3-bromo-1-phenylnaphthalene) with a yield of 70.7%, a purity of 98.0%, and a melting point of 65.1°C.

[0073] Comparative Example

[0074] Comparative Example 1

[0075] A method for synthesizing 3-bromo-1-phenylnaphthalene, comprising the following steps:

[0076] S1, add 42g (192mmol) of 1-phenyl-4-naphthylamine into a round-bottom flask, add 300mL of dimethylformamide thereto, stir and mix, add a dimethylformamide solution of N-bromosuccinimide dropwise into the mixture at 0°C, the dimethylformamide solution of N-bromosuccinimide being obtained by dissolving 34.1g (192mmol) of N-bromosuccinimide in 120mL of dimethylformamide solution, stir and react at room temperature (25°C) for 12h after the addition, pour the obtained product into 1000mL of pure water after the reaction, filter, collect the filter residue, purify, and dry to obtain 36g of 1-phenyl-3-bromo-4-naphthylamine, with a yield of 63%;

[0077] S2, put 36g (121mmol) of 1-phenyl-3-bromo-4-naphthylamine obtained in S1 into a round-bottom flask, and add 540mL of tetrahydrofuran thereto, stir and mix, add 159.4g (2.415mol) of hypophosphorous acid to the mixture at 0°C, and add 25g (362mmol) of sodium nitrate, stir for 4h, warm to room temperature (25°C) and continue stirring and reacting for 12h, add dichloromethane and water after the reaction, and adjust the pH of the mixture to 10 with 2mol / L sodium hydroxide solution, extract the organic layer, purify and dry to obtain 18g of 3-bromo-1-phenylnaphthalene with a yield of 53%.

[0078] By comparing the synthesis methods of Example 1 and Comparative Example 1, it can be seen that compared with the synthesis method recorded in Example 1, the raw material 1-phenyl-4-naphthylamine of Comparative Example 1 is obtained by palladium-catalyzed coupling of 1-bromo-4-naphthylamine, or by nitration of 1-phenylnaphthalene and then reduction. The costs of both methods are very high, resulting in a high raw material cost for Comparative Example 1. In addition, the S2 step of Comparative Example 1 is a diazotization reduction reaction, which not only has high requirements on the reaction conditions, but also has a low yield of only 53%. The reaction route of Example 1 not only has simple and easy-to-obtain raw materials, simple operation, but also has a yield of up to 74.2%.

[0079] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for synthesizing 3-bromo-1-phenylnaphthalene, characterized in that: The steps include: Bromobenzene was used as a raw material to prepare the bromobenzene Grignard reagent; 1-Tetralone reacts with bromobenzene Grignard reagent to produce a mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene; A mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dilinonaphthalene undergoes bromination reaction with N-bromosuccinimide in the presence of an initiator to generate 3-bromo-1-phenylnaphthalene; The molar ratio of bromobenzene to 1-tetralone is (1.125-1.250):1; The solvent of the bromination reaction is chloroform, and the weight ratio of the mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene to chloroform in the bromination reaction is 1:(9-11); The initiator of the bromination reaction is azobisisobutyronitrile, and the weight ratio of the mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene to azobisisobutyronitrile in the bromination reaction is 1:(0.045-0.073).

2. The method for synthesizing 3-bromo-1-phenylnaphthalene according to claim 1, characterized in that: The molar ratio of bromobenzene to 1-tetralone is 1.250:

1.

3. The method for synthesizing 3-bromo-1-phenylnaphthalene according to claim 1, characterized in that: The reaction temperature of 1-tetralone and bromobenzene Grignard reagent is not higher than 60°C.

4. The method for synthesizing 3-bromo-1-phenylnaphthalene according to claim 1, characterized in that: In the bromination reaction, the molar ratio of the mixture of 1-phenyl-1-hydroxytetralin and 1-phenyl-3,4-dihydronaphthalene to N-bromosuccinimide is 1:2.

2.

5. The method for synthesizing 3-bromo-1-phenylnaphthalene according to claim 1, characterized in that: The bromination reaction time is 15 to 20 hours.

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