Synthetic method of 10-hydroxybenzo [H] quinoline

Abstract

The invention discloses a synthesis method of 10-hydroxybenzo [H] quinoline, which comprises the following steps: carrying out Skraup cyclization reaction on a crude product 8-amino-1-naphthalene sulfonic acid and glycerol to generate 10-sulfonic acid benzoquinoline, further removing sulfonyl in molten sodium hydroxide, acidifying, neutralizing, extracting, decolorizing and recrystallizing to obtain the product 10-hydroxybenzo quinoline. According to the synthesis method of the 10-hydroxybenzo [H] quinoline, the reaction temperature is reduced to 200 DEG C from original 300 DEG C, energy consumption is reduced, by-products and the carbonization degree in the reaction process are controlled due to reduction of the reaction temperature, the yield is greatly increased, and the raw material cost is greatly reduced; the reaction system is adjusted from solid alkali fusion to liquid alkali reaction, the product is easier to obtain after the reaction is finished, and the mass production operability of the product is improved.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis, and in particular to a method for synthesizing 10-hydroxybenzo[H]quinoline. Background Art

[0002] 10-Hydroxybenzo[H]quinoline is an organic synthesis intermediate and pharmaceutical intermediate, mainly used in laboratory research and development processes and chemical production processes. Its derivatives have been widely used in electronics, luminescent materials, etc.

[0003] The melting point of 10-hydroxybenzo[H]quinoline is 103-105°C, the boiling point is 420.6°C, the appearance is yellow crystal, it is easily soluble in toluene, ethyl acetate, ethanol, THF, DMF and other solvents, it has oxidizing properties, and its main use is in the production of OLEDs;

[0004] In the existing synthesis method of 10-hydroxybenzo[H]quinoline, the reaction system is solid alkali fusion, and the product after the reaction is not easy to obtain. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems and provide a method for synthesizing 10-hydroxybenzo[H]quinoline.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A method for synthesizing 10-hydroxybenzo[H]quinoline comprises the following reaction process:

[0008] S1: 8-amino-1-naphthalenesulfonic acid and glycerol undergo a Skraup cyclization reaction to generate 10-benzoquinolinesulfonate. The reaction formula is as follows:

[0009]

[0010] S2: 10-Sulfonic acid benzoquinoline is desulfonated in molten sodium hydroxide, and then acidified, neutralized, extracted, decolorized and recrystallized to obtain the product 10-hydroxybenzo[H]quinoline. The reaction formula is as follows:

[0011]

[0012] Furthermore, the reaction process of S1 includes the following steps:

[0013] (1) adding glycerol, phosphoric acid, nitrobenzene and ferrous sulfate into a reaction vessel and stirring, and then adding 8-amino-1-naphthalenesulfonic acid wet product;

[0014] (2) the reaction container is heated to 100° C., and concentrated sulfuric acid is added dropwise to the reaction container. During the addition, the temperature inside the reaction container is lower than 120° C.;

[0015] (3) After the addition is completed, the temperature in the reaction container is raised to 120° C. to 130° C. and kept warm. After the insulation is completed, the temperature in the reaction container is lowered to 110° C., and concentrated sulfuric acid is added to the reaction container again. The temperature in the reaction container is lower than 120° C. during the addition process. After the addition is completed, the temperature in the reaction container is raised to 130° C. to 140° C., and the reaction is kept warm for 1 hour. Sampling and testing are started (QCP-1: LC: raw material <1.0%, attached Figure 1 , raw material = 1641ppm, main = 78.2352%), about 2h, stop the reaction and cool down, the finished product is named YNK01-S1.

[0016] (Sampling method: Take 1 ml of the reaction solution, add 4 ml of acetic acid + 1 ml of water to dissolve, and send the whole sample to LC)

[0017] Post-treatment: Cool the reaction solution to 70-80°C, transfer to 95L hot water at 70-80°C, rinse the reactor with 5L tap water, combine and add to the post-treatment solution. Control the system temperature at 70-80°C and stir for 0.5h, then cool to 35-45°C.

[0018] Beating: Start filtering, beat the filter cake with 35L of hot water at 70-80℃ for 0.5h, then cool to 35-45℃. Filter, beat the filter cake with 10L of dichloroethane at room temperature for 0.5h, filter, and drain to obtain 7.2kg of crude 10-hydroxybenzo[H]quinoline-S1.

[0019] Drying material: Spread 7.2 kg of the filtered wet product into a stainless steel plate with plastic paper, dry the material at 80°C with air blowing, turn the material over every 4 hours, dry the material for 24 hours, and obtain 3.88 kg of dried product. Take samples for inspection (QCP-2: LC main content>85.0%, nitrobenzene<15.0%, attached Figure 2 , main = 92%).

[0020] Yield: 66.8% (based on wet 8-amino-1-naphthalenesulfonic acid)

[0021] Duration: 3.0 days.

[0022] Further, the reaction process of S2 includes the following steps:

[0023] (1) Adding a 70% sodium hydroxide solution and crude 10-hydroxybenzo[H]quinoline to a heated autoclave and heating the autoclave to 200° C. to 220° C. and a pressure of 1.5 MPa to 2.0 MPa, and keeping the temperature until the reaction is completed. The autoclave is cooled to 75° C. to 80° C., and samples are taken for testing.

[0024] (2) adding water to the heated autoclave and keeping the temperature at 80° C. to 90° C. for 1 hour, filtering and draining to obtain a filtrate and a filter cake, and washing the filter cake with water and draining to obtain a black-red solid;

[0025] (3) adding water and the black-red solid into a glass kettle and stirring, heating to 60° C. to 65° C. and stirring, and after the stirring, dripping concentrated hydrochloric acid into the glass kettle, wherein the temperature in the reaction kettle is less than 40° C. during the dripping process, adjusting the pH value of the liquid in the glass kettle to 3 to 4;

[0026] (4) adding a sodium bicarbonate aqueous solution (4.5 kg sodium bicarbonate + 20 kg water) dropwise into the glass kettle to adjust the pH of the liquid in the glass kettle to 8;

[0027] (5) Add 50 L of toluene (YNK01-S1: toluene = 1 kg: 5 L) into the glass kettle, adjust the temperature in the glass kettle to 30° C. to 40° C. and stir, and after stirring, let the mixture stand for separation;

[0028] (6) Mix the aqueous phase and toluene after separation and stir. After stirring (YNK01-S1: toluene = 1 kg: 5 L), let stand to separate the liquids and combine the organic phases;

[0029] (7) mixing the organic phase with water and stirring, and allowing the mixture to stand for separation after the stirring is completed;

[0030] (8) After decolorization and recrystallization, the product 10-hydroxybenzo[H]quinoline was obtained and named YNK01-S2.

[0031] The beneficial effects of the present invention are:

[0032] 1. The reaction temperature is reduced from 300°C to 200°C, which is beneficial to reducing energy consumption. The reduction of reaction temperature can control the generation of by-products and the degree of carbonization in the reaction process, greatly improve the yield, and significantly reduce the cost of raw materials;

[0033] 2. The reaction system is adjusted from solid alkali fusion to liquid alkali reaction. The product is easier to obtain after the reaction, which improves the mass production operability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 LC spectrum of YNK01-S1 reaction;

[0035] Figure 2 LC spectrum of crude YNK01-S1;

[0036] Figure 3 LC spectrum of YNK01-S2 reaction;

[0037] Figure 4 YNK01-S2 decolorization LC spectrum;

[0038] Figure 5 Column LC spectrum of YNK01-S2;

[0039] Figure 6 YNK01-S2 recrystallization LC spectrum;

[0040] Figure 7 YNK01-S2 fine drying LC spectrum;

[0041] Figure 8 YNK01-S2 warehouse inspection report. DETAILED DESCRIPTION

[0042] The following examples may enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0043] A method for synthesizing 10-hydroxybenzo[H]quinoline comprises the following reaction process:

[0044] S1: 8-amino-1-naphthalenesulfonic acid and glycerol undergo a Skraup cyclization reaction to generate 10-benzoquinolinesulfonate. The reaction formula is as follows:

[0045]

[0046] S2: 10-Sulfonic acid benzoquinoline is desulfonated in molten sodium hydroxide, and then acidified, neutralized, extracted, decolorized and recrystallized to obtain the product 10-hydroxybenzo[H]quinoline. The reaction formula is as follows:

[0047]

[0048] In this preferred embodiment, the reaction process of S1 includes the following steps:

[0049] (1) adding glycerol, phosphoric acid, nitrobenzene and ferrous sulfate into a reaction vessel and stirring, and then adding 8-amino-1-naphthalenesulfonic acid wet product;

[0050] (2) the reaction container is heated to 100° C., and concentrated sulfuric acid is added dropwise to the reaction container. During the addition, the temperature inside the reaction container is lower than 120° C.;

[0051] (3) After the addition is completed, the temperature in the reaction container is raised to 120° C. to 130° C. and kept warm. After the insulation is completed, the temperature in the reaction container is lowered to 110° C., and concentrated sulfuric acid is added to the reaction container again. The temperature in the reaction container is lower than 120° C. during the addition process. After the addition is completed, the temperature in the reaction container is raised to 130° C. to 140° C., and the reaction is kept warm for 1 hour. Sampling and testing are started (QCP-1: LC: raw material <1.0%, attached Figure 1, raw material = 1641ppm, main = 78.2352%), about 2h, stop the reaction and cool down.

[0052] (Sampling method: Take 1 ml of the reaction solution, add 4 ml of acetic acid + 1 ml of water to dissolve, and send the whole sample to LC)

[0053] Post-treatment: Cool the reaction solution to 70-80°C, transfer to 95L hot water at 70-80°C, rinse the reactor with 5L tap water, combine and add to the post-treatment solution. Control the system temperature at 70-80°C and stir for 0.5h, then cool to 35-45°C.

[0054] Beating: Start filtering, beat the filter cake with 35L of hot water at 70-80°C for 0.5h, then cool to 35-45°C. Filter, beat the filter cake with 10L of dichloroethane at room temperature for 0.5h, filter, and drain to obtain 7.2kg of crude 10-hydroxybenzo[H]quinoline-S1 (the finished product is named YNK01-S1).

[0055] Drying material: Spread 7.2 kg of the filtered wet product into a stainless steel plate with plastic paper, dry the material at 80°C with air blowing, turn the material over every 4 hours, dry the material for 24 hours, and obtain 3.88 kg of dried product. Take samples for inspection (QCP-2: LC main content>85.0%, nitrobenzene<15.0%, attached Figure 2 , main = 92%).

[0056] Yield: 66.8% (based on wet 8-amino-1-naphthalenesulfonic acid)

[0057] Duration: 3.0 days.

[0058] In this preferred embodiment, the reaction process of S2 includes the following steps:

[0059] (1) Adding a 70% sodium hydroxide solution and crude 10-hydroxybenzo[H]quinoline to a heated autoclave and heating the autoclave to 200° C. to 220° C. and a pressure of 1.5 MPa to 2.0 MPa, and keeping the temperature until the reaction is completed. The autoclave is cooled to 75° C. to 80° C., and samples are taken for testing.

[0060] (2) adding water to the heated autoclave and keeping the temperature at 80° C. to 90° C. for 1 hour, filtering and draining to obtain a filtrate and a filter cake, and washing the filter cake with water and draining to obtain a black-red solid;

[0061] (3) adding water and the black-red solid into a glass kettle and stirring, heating to 60° C. to 65° C. and stirring, and after the stirring, dripping concentrated hydrochloric acid into the glass kettle, wherein the temperature in the reaction kettle is less than 40° C. during the dripping process, adjusting the pH value of the liquid in the glass kettle to 3 to 4;

[0062] (4) adding a sodium bicarbonate aqueous solution (4.5 kg sodium bicarbonate + 20 kg water) dropwise into the glass kettle to adjust the pH of the liquid in the glass kettle to 8;

[0063] (5) Add 50 L of toluene (YNK01-S1: toluene = 1 kg: 5 L) into the glass kettle, adjust the temperature in the glass kettle to 30° C. to 40° C. and stir, and after stirring, let the mixture stand for separation;

[0064] (6) Mix the aqueous phase and toluene after separation and stir. After stirring (YNK01-S1: toluene = 1 kg: 5 L), let stand to separate the liquids and combine the organic phases;

[0065] (7) mixing the organic phase with water and stirring, and allowing the mixture to stand for separation after the stirring is completed;

[0066] (8) After decolorization and recrystallization, the product 10-hydroxybenzo[H]quinoline (YNK01-S2) was obtained.

[0067] Example 1

[0068] S1:

[0069]

[0070] S2:

[0071]

[0072] S1 reaction:

[0073]

[0074] FW: 223 92.1 123 98 98 151.91 259 mol:1.0 4.03 1.1 3.22 3.75 0.025m

[0075]

[0076] Reaction vessel: 50L glass kettle

[0077] Reaction process: Add 8.33kg of glycerol, 8.33kg of phosphoric acid, 3.03kg of nitrobenzene (reagent bottle), and 0.125kg of ferrous sulfate to a clean, dry 50L glass kettle. Start stirring, and then add 5kg of wet 8-amino-1-naphthalenesulfonic acid, and the addition is complete. Turn on the heating and raise the temperature to 100℃, add 4.2kg of concentrated sulfuric acid dropwise (a large amount of white mist is generated during the addition), and the temperature during the addition process is controlled to <120℃. After the addition is completed, the temperature is raised to 120-130℃, and the reaction is kept warm for 2h. The system is cooled to 110℃, and 4.2kg of concentrated sulfuric acid is added dropwise again. The temperature during the addition process is controlled to <120℃. After the addition is completed, the temperature is slowly raised to 130-140℃, and the reaction is kept warm for 1h, and sampling and testing are started (QCP-1: LC: raw material <1.0%, attached Figure 1 , raw material = 1641ppm, main = 78.2352%), about 2h, stop the reaction and cool down.

[0078] (Sampling method: Take 1 ml of the reaction solution, add 4 ml of acetic acid + 1 ml of water to dissolve, and send the whole sample to LC)

[0079] Post-treatment: Cool the reaction solution to 70-80°C, transfer to 95L hot water at 70-80°C, rinse the reactor with 5L tap water, combine and add to the post-treatment solution. Control the system temperature at 70-80°C and stir for 0.5h, then cool to 35-45°C.

[0080] Beating: Start filtering, beat the filter cake with 35L of hot water at 70-80℃ for 0.5h, then cool to 35-45℃. Filter, beat the filter cake with 10L of dichloroethane at room temperature for 0.5h, then filter, and drain to obtain 7.2kg of crude YNK01-S1.

[0081] Drying material: Spread 7.2 kg of the filtered wet product into a stainless steel plate with plastic paper, dry the material at 80°C with air blowing, turn the material over every 4 hours, dry the material for 24 hours, and obtain 3.88 kg of dried product. Take samples for inspection (QCP-2: LC main content>85.0%, nitrobenzene<15.0%, attached Figure 2 , main = 92%).

[0082] Yield: 66.8% (based on wet 8-amino-1-naphthalenesulfonic acid)

[0083] Cycle: 3.0 days

[0084] S2 reaction:

[0085]

[0086] FW: 259 40.0 18 195

[0087] Wt: 1.0 10

[0088]

[0089] Ingredients: Add 6.62L of water to a 50L stainless steel oil heating kettle, and slowly add sodium hydroxide. Control the temperature at 75-80°C to completely dissolve it into a 70% sodium hydroxide solution, and keep it warm for later use.

[0090] Reaction vessel: 50L stainless steel oil-heated autoclave, heating capacity >270°C.

[0091] Reaction: Add the prepared sodium hydroxide solution to a 50L stainless steel oil-heated autoclave, then add 10kg of YNK01-S1, close the autoclave cover, fill with nitrogen for replacement (3 times) and check the air tightness. Then turn on the heating, raise the temperature to 200-220℃ (P=1.5-2.0MPa), keep the temperature for 4h, cool to 75-80℃, take samples for testing, and stop the reaction when the raw material is <1.0% (QCP-3: raw material <1.0%).

[0092] (Sampling method: Take 1 ml of the reaction solution, add 4 ml of acetic acid + 1 ml of water to dissolve, and send the whole sample to LC)

[0093] Discharge: Cool the reaction liquid to 80-90℃, open the drain valve to drain, open the kettle cover, add 6.62L of water, keep warm at 80-90℃ for 1h, filter while hot, drain, collect the filtrate separately, rinse the filter cake twice with 1L of water and drain, and obtain a black-red solid with a wet weight of 8kg

[0094] Post-treatment: Add 24L of water to a 50L glass kettle, then add 8kg of black-red solid, start stirring, heat to 60-65℃ and stir for 0.5h, then cool to room temperature. Start dripping about 8kg of concentrated hydrochloric acid, control the temperature <40℃ during the dripping process, adjust the pH to 3-4 (QCP-4: pH=3-4), and measure the pH value of the system after stirring for 30min. After confirming that pH=3-4, add sodium bicarbonate aqueous solution (4.5Kg sodium bicarbonate + 20Kg water) under stirring, adjust pH=8 (QCP-5: pH=8), and measure the pH value of the system after stirring for 30min. After confirming that pH=8, add 50L of toluene (YNK01-S1: toluene=1Kg:5L), control the temperature at 30-40℃ and stir for 1h. Stop stirring, let stand for 3h, then separate the liquids, and temporarily put the organic phase. Add the aqueous phase to the kettle, then add 50L toluene (YNK01-S1: toluene = 1Kg: 5L), stir for 30min, let stand for 1h and then separate. Discard the aqueous phase and combine the organic phases. Add 40L of water to the organic phase (YNK01-S1: water = 1Kg: 4L), stir for 30min, let stand for 2h and then separate.

[0095] Concentration: Turn on the heating and raise the temperature to 80-85°C. The system refluxes and foams appear. Reflux water and collect the fractions to recover toluene. Reflux until the system temperature reaches 105-110°C and continue to concentrate until about 11L remains (YNK01-S1: toluene = 1Kg: 2.5L).

[0096] Decolorization: Cool the system to 70-80℃, add 3Kg of activated carbon (YNK01-S1: activated carbon = 1Kg: 0.3Kg), keep warm and stir for 1h, cool to 20-30℃ and filter, spread 4Kg of silica gel in the funnel (shovel out the activated carbon when filtering is slow), and rinse the filter cake with 6L of toluene (activated carbon: toluene = 1Kg: 2L). Add the filtrate to the kettle, and then add 2Kg of activated carbon (YNK01-S1: activated carbon = 1Kg: 0.2Kg). Turn on the stirring, heat the system to 70-80℃ and stir for 1h, cool to 20-30℃ and filter, and rinse the filter cake with 4L of toluene (activated carbon: toluene = 1Kg: 2L). Combine the organic phases to pass through the column, and collect the activated carbon to recover the product.

[0097] Column passing: pass the combined organic phase through a normal temperature silica gel column, 4.0 kg of silica gel (80-120 mesh, column diameter = 10 cm, column height = 20 cm), moisten the silica gel with 8 L of toluene (m silica gel: V toluene = 1 kg: 2 L), after the column passing is completed, rinse the silica gel with 15 L of toluene (YNK01-S1: toluene = 1 kg: 1.5 L), combine the column liquid and the elution liquid and concentrate under reduced pressure (T < 85 ° C, P = -0.08 ~ -0.09 MPa) until no solvent flows out, and continue to pump negative pressure for 1 hour.

[0098] Primary recrystallization: add 14L of ethanol (YNK01-S1: ethanol = 1Kg: 1.4L) to the kettle, turn on the heating and heat to 75-80℃ for reflux, the system is dissolved clearly (confirm that the solution is clear), slowly cool down to 30-35℃, continue to cool down to 0-5℃, filter, rinse with 1.0L of ice ethanol, filter and dry to obtain YNK01: 6.82Kg. Take samples for inspection

[0099] Secondary recrystallization: add 85% of the wet product to a 10L bottle, add 25L of ethanol (YNK01 dry: ethanol = 1Kg: 4L), start stirring, heat to 75-80℃, reflux to dissolve clearly, slowly cool to 30-35℃, continue to cool to 0-5℃, filter, rinse with 1.0L of ethanol, filter and dry to obtain 5.92kg of YNK01 wet product, take samples for inspection (QCP-6: LC>99.0%, attached Figure 6 , main = 99.7344%).

[0100] Drying: Blast drying oven, temperature 55-60℃, about 12h, 4.141kg of yellow crystals were obtained. (QCP-7: LC>99.0%, loss on drying <0.5%, no mechanical impurities were observed)

[0101] Yield: 55% (based on YNK01-S1)

[0102] Duration: 11 days

[0103] Total process yield: 36.8% (based on 8-amino-1-naphthalenesulfonic acid)

[0104] Total process cycle: 14.0 days

[0105] Three Waste Treatment

[0106]

[0107]

[0108] Key Points:

[0109] 1. When sampling and discharging, the system temperature must be lowered to below 100°C to prevent high pressure from causing material impact.

[0110] 2. The pH index must be strictly controlled during acid adjustment, and the actual amount of hydrochloric acid used shall prevail.

[0111] 3. The pH index must be strictly controlled when adjusting the alkali, and the actual amount of sodium bicarbonate used shall prevail.

[0112] 4. The reflux distilled water feeding system should be about 60-70% of the kettle volume to avoid material impact.

[0113] 5. Activated carbon needs to be recovered before being processed.

[0114] 6. The cooling of recrystallization should not be too fast, and gradient cooling has a better effect.

[0115] Activated carbon treatment:

[0116] Add 6L of toluene to the recovered activated carbon (activated carbon: toluene = 1kg: 3L), heat to 70-80℃ and slurry for 30min, cool to 20-30℃ and filter. Repeat this step 2 more times (slurry 3 times in total), combine the 3 slurry toluene phases, concentrate until about 3L (activated carbon: toluene phase = 1kg: 1.5L) remain in the system, cool to room temperature, pass through a normal temperature silica gel column, and after the column is completed, rinse with 3L of toluene. Combine the column liquid and the elution liquid, concentrate and dry, and then recrystallize (same as the above concentration and recrystallization steps) to a main content of >99.0%.

[0117] Mother liquor treatment:

[0118] All mother liquors were combined and concentrated to obtain 320g of mother liquor recovery product, and 1.6L of toluene (YNK01 concentrated dry: toluene = 1kg: 5L) was added to dissolve it clearly, and it was passed through a normal temperature silica gel column. After the column was completed, it was eluted with 1.6L of toluene. The column liquid and the eluent were combined, concentrated to dryness, and 1.2L of ethanol (YNK01: ethanol = 1g: 4ml) was added, and the temperature was raised to reflux, and the solution was dissolved clearly, and then the temperature was lowered to 20-25℃ and kept warm for 30min, and then filtered, and the mother liquor recovery product was recrystallized twice at 75% dryness until the main content was >99.0%, and 120g of mother liquor recovery product was obtained after drying.

[0119] Note: The mother liquor is recycled to recover toluene and ethanol

[0120] Mother liquor yield: 4.1%

[0121] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for synthesizing 10-hydroxybenzo[H]quinoline, characterized in that: Including the following reaction process: S1: 8-amino-1-naphthalenesulfonic acid and glycerol undergo a Skraup cyclization reaction to generate 10-benzoquinolinesulfonate. The reaction formula is as follows: S2: 10-Sulfonic acid benzoquinoline is desulfonated in molten sodium hydroxide, and then acidified, neutralized, extracted, decolorized and recrystallized to obtain the product 10-hydroxybenzo[H]quinoline. The reaction formula is as follows:

2. A method for synthesizing 10-hydroxybenzo[H]quinoline according to claim 1, characterized in that: The reaction process of S1 includes the following steps: (1) adding glycerol, phosphoric acid, nitrobenzene and ferrous sulfate into a reaction vessel and stirring, and then adding 8-amino-1-naphthalenesulfonic acid wet product; (2) the reaction container is heated to 100° C., and concentrated sulfuric acid is added dropwise to the reaction container. During the addition, the temperature inside the reaction container is lower than 120° C.; (3) After the addition is completed, the temperature in the reaction container is raised to 120° C. to 130° C. and kept warm. After the insulation is completed, the temperature in the reaction container is lowered to 110° C. and concentrated sulfuric acid is added to the reaction container again. The temperature in the reaction container is lower than 120° C. during the addition process. After the addition is completed, the temperature in the reaction container is raised to 130° C. to 140° C. and kept warm for 1 hour, and sampling and testing are started.

3. A method for synthesizing 10-hydroxybenzo[H]quinoline according to claim 1 or 2, characterized in that: The reaction process of S2 includes the following steps: (1) Adding a 70% sodium hydroxide solution and crude 10-hydroxybenzo[H]quinoline to a heated autoclave and heating the autoclave to 200° C. to 220° C. and a pressure of 1.5 MPa to 2.0 MPa, and keeping the temperature until the reaction is completed. The autoclave is cooled to 75° C. to 80° C., and samples are taken for testing. (2) adding water to the heated autoclave and keeping the temperature at 80° C. to 90° C. for 1 hour, filtering and draining to obtain a filtrate and a filter cake, and washing the filter cake with water and draining to obtain a black-red solid; (3) adding water and the black-red solid into a glass kettle and stirring, heating to 60° C. to 65° C. and stirring, and after the stirring, dripping concentrated hydrochloric acid into the glass kettle, wherein the temperature in the reaction kettle is less than 40° C. during the dripping process, adjusting the pH value of the liquid in the glass kettle to 3 to 4; (4) adding a sodium bicarbonate aqueous solution dropwise into the glass kettle to adjust the pH value of the liquid in the glass kettle to 8; (5) Add 50 L of toluene (YNK01-S1: toluene = 1 kg: 5 L) into the glass kettle, adjust the temperature in the glass kettle to 30° C. to 40° C. and stir, and after stirring, let the mixture stand for separation; (6) Mixing the aqueous phase and toluene after separation and stirring, standing and separating the liquids after stirring, and combining the organic phases; (7) mixing the organic phase with water and stirring, and allowing the mixture to stand for separation after the stirring is completed; (8) The product 10-hydroxybenzo[H]quinoline is obtained by decolorization and recrystallization.

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