Preparation method of musk T

Abstract

The invention discloses a preparation method of musk T. The musk T is prepared by carrying out esterification and depolymerization reaction on tridecanedioic acid and ethylene glycol under the action of a catalyst, and the method is mild in reaction condition, simple and convenient to operate, few in three wastes, high in yield, low in energy consumption, low in cost and easy to industrialize, and is a green and efficient method for preparing the musk T.

Description

Technical Field

[0001] The invention belongs to the field of fine chemicals, and specifically relates to a method for preparing musk T. Background Art

[0002] Musk has a noble, elegant, mild, deep, and delicate aroma, renowned for its long-lasting aroma. It has excellent blending and aroma-enhancing properties in perfumery. However, due to its scarcity and high price, natural musk is far from meeting consumer demand. Consequently, research into synthetic musk is of particular importance. Synthetic musks are categorized into three main categories: nitromusks, polycyclic musks, and macrocyclic musks. In recent years, nitromusks have been gradually withdrawn from the market due to safety and environmental concerns. Studies have shown that polycyclic musks enter the human food chain, accumulate in the human body, and are difficult to degrade in the environment. The potential harms of polycyclic musks to human health and the environment are becoming increasingly prominent, leading to a new phase in the research of synthetic musk methods. Compared to other synthetic musks, the aroma of macrocyclic musks is more elegant and luxurious, and most closely resembles that of natural musk. Consequently, macrocyclic musks have become a key area of ​​development in the musk industry in recent years, with Musk T, a representative example, becoming a major research focus.

[0003] Patent CN111620773A discloses a method for preparing dibasic acid from musk T still residue. This method involves depolymerizing the still residue into tridecanedioic acid using a zinc salt as a catalyst in a strong alkaline environment. Crystallized tridecanedioic acid is then obtained after multiple crystallization and washing. The strong base and dilute acid used in this process can corrode the equipment, and the acid-base neutralization process produces a large amount of wastewater and waste liquid, which is not in line with the concept of green chemical engineering.

[0004] Patent CN105884742A discloses a method for preparing musk T. This method uses a high-temperature esterification method in the esterification stage and a composite metal catalyst for depolymerization. Due to the high temperature esterification, this method has many side reactions, and the polymerization and depolymerization reaction conditions are harsh, requiring large equipment investment.

[0005] How to create a preparation method of musk T with mild reaction conditions, higher yield and low cost is of great positive significance. Summary of the invention:

[0006] To address the above process issues, the present invention proposes a method for preparing musk T. This method utilizes a modified catalyst and changes the reaction conditions at different reaction stages to produce musk T in a single step. The catalyst and byproducts of the reaction process can be reused. This method has mild reaction conditions, simple operation, low waste, high yield, low energy consumption, low cost, and is easy to industrialize. It is a green and efficient method for preparing musk T.

[0007] To achieve the above object, the technical solutions adopted by the present invention are as follows:

[0008] A method for preparing musk T comprises the following steps: subjecting tridecanedioic acid and ethylene glycol to esterification and depolymerization under the action of a catalyst to prepare musk T.

[0009] Preferably, a monohydric alcohol is added during the reaction to adjust the degree of polymerization of the esterification reaction.

[0010] Preferably, the esterification reaction temperature is 100-150°C, preferably 110-140°C; the depolymerization reaction temperature is 150-250°C, preferably 180-220°C.

[0011] The present application uses tridecanedioic acid and ethylene glycol as raw materials, adjusts the esterification polymerization degree by adding monohydric alcohol, uses the same catalyst in two different reaction stages of esterification and depolymerization, controls the reaction progress by changing the temperature and pressure of the reaction system, and finally prepares musk T. The catalyst and by-products used can be directly reused for preparation.

[0012] Preferably, the molar ratio of tridecanedioic acid to ethylene glycol is 1:1-1:1.5, more preferably 1:1.1-1:1.2;

[0013] Preferably, the monohydric alcohol is selected from one or more of n-hexanol, n-octanol, 2-ethylhexanol, etc.;

[0014] Preferably, the amount of the monohydric alcohol added is 0.5-5% of the molar amount of tridecanedioic acid, preferably 2.5-5%;

[0015] Preferably, the reaction catalyst is a sulfonic acid modified catalyst;

[0016] Preferably, the preparation method of the catalyst comprises the following steps:

[0017] (1) Preparation of COP vector

[0018] (1-1) Paraformaldehyde (PA), melamine (MA), and an alkaline catalyst are added to water and mixed;

[0019] (1-2) dissolving a nonionic surfactant in an acidic solution, adding the solution to an alcohol-water solution, mixing the solution uniformly, and then adding the mixture to the solution obtained in step (1-1), reacting the solution, cooling the solution to room temperature, and filtering the solution to obtain a carrier, which is represented by PA-MA;

[0020] (2) Load

[0021] The carrier PA-MA prepared in step (1) is added to a mixture of sultone and the first solvent to load the sultone on the carrier. Then, CF3SO3H is added to react. After the reaction is completed, the catalyst is separated, washed, and dried to obtain the catalyst.

[0022] Preferably, the added alkaline catalyst includes but is not limited to sodium hydroxide, potassium hydroxide, sodium ethoxide, sodium methoxide, and aqueous ammonia;

[0023] Preferably, the reaction temperature of step (1-1) is 80-100°C;

[0024] Preferably, the acidic solution is an acid solution, and the acid includes one or more of hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, p-toluenesulfonic acid, aminosulfonic acid, etc.

[0025] Preferably, the alcohol in the alcohol-water solution includes but is not limited to methanol, ethanol, ethylene glycol, propylene glycol, glycerol, etc.;

[0026] Preferably, in step (1-2), the mixed solution and the reaction solution obtained in step (1-1) are reacted at 150° C. to 180° C.;

[0027] Preferably, the carrier obtained by filtration is refluxed with ethanol, and the residual surfactant can be removed after reflux with ethanol.

[0028] Preferably, in step (1-1), the mass ratio of paraformaldehyde to melamine is 1:(1.2-1.8);

[0029] Preferably, in step (1-1), the molar ratio of alkali to melamine is (0.03-0.06):1;

[0030] Preferably, in step (1-1), the amount of water added is 2-5 times the mass of paraformaldehyde.

[0031] Preferably, in step (1-2), the mass ratio of surfactant to melamine is (0.2-0.6):1;

[0032] Preferably, the nonionic surfactant is one or more of a polyether surfactant and a polyether-polyester block surfactant, preferably a copolymer of ethylene oxide and propylene oxide, a block copolymer of polyoxypropylene glycol and ethylene oxide, more preferably Poloxamer 407 and Poloxamer F127;

[0033] Preferably, in step (1-2), the molar ratio of acid to melamine is (0.5-1.0):1;

[0034] Preferably, in step (1-2), the mass ratio of water to alcohol in the alcohol-water solution is (0.5-1):1;

[0035] Preferably, in step (1-2), the molar ratio of alcohol to melamine is (2-5):1;

[0036] In step (2), the mass ratio of sultone to PA-MA is (0.1-0.5):1;

[0037] Preferably, the sultone is selected from 1,4-butane sultone or 1,3-propane sultone.

[0038] After adding sultone in step (2), heating and reflux are carried out for 24-48 hours for loading.

[0039] The mass ratio of CF3SO3H to PA-MA in step (2) is (0.05-0.5):1

[0040] In step (2), the first solvent is selected from toluene or ethylbenzene, and the mass ratio of the added solvent to the PA-MA is (20-50):1.

[0041] Preferably, in step (2), the reaction temperature after adding CF3SO3H is 60-70°C and the reaction time is 24-48 hours. After the reaction is completed, the mixture is allowed to stand for separation, and the separated product is washed with dichloromethane.

[0042] Preferably, in step (2), the drying temperature is 80-100° C., and the drying time is 24-48 hours.

[0043] In the preparation method of musk T, the amount of catalyst added is 0.5wt%-20wt% of the mass of the raw material tridecanedioic acid, preferably 2wt%-10wt%;

[0044] In the preparation method of musk T, the reaction is carried out in a second solvent, which is toluene or ethylbenzene;

[0045] The amount of the second solvent added is 10%-20% of the mass of the tridecanedioic acid;

[0046] The esterification reaction can be carried out under normal pressure;

[0047] The reaction time of the esterification stage is 3h-10h, preferably 3-5h;

[0048] The pressure in the depolymerization stage is 20-30 PaA;

[0049] The reaction time of the depolymerization stage is 3 h to 10 h, preferably 5 h to 8 h.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The present application provides a new catalyst that can not only catalyze the esterification reaction of tridecanedioic acid and ethylene glycol, but also catalyze the depolymerization of the esterification product to prepare musk T. It can complete two reactions in one step, saving the process and reducing the loss and cost caused by catalyst replacement. The present application controls the degree of reaction by controlling the reaction temperature. The operation method is simple, the reaction conditions are mild and easy to control, and the catalyst and by-products of the reaction process can be reused. This method has few three wastes, high yield, low energy consumption, low cost and easy industrialization. It is a green and efficient method for preparing musk T. DETAILED DESCRIPTION

[0052] In order to better understand the technical solutions of the present invention, the present invention is further described below with reference to the following embodiments, but the present invention is not limited to the following embodiments.

[0053] The main raw materials of the present invention, Poloxamer 407, Poloxamer F127, paraformaldehyde (PA), melamine (MA), 1,3-propane sultone, 1,4-butane sultone, and CF3SO3H, were purchased from Aladdin Reagent Company with analytical grade specifications.

[0054] The following instruments were used to analyze selectivity and conversion in the examples:

[0055] An Agilent 1200 series liquid chromatograph was equipped with a C18 liquid chromatographic column. The column temperature was set at 40°C, the mobile phase was methanol:acetonitrile:water = 80:5:15 (0.1% trifluoroacetic acid), the flow rate was 1.2 mL / min, and detection was performed at a UV detector at a wavelength of 210 nm. Quantification was performed using n-tetradecane as the internal standard.

[0056] The NMR spectrometer was a Brucker AC-200 (200 MHz). CDCl3 was used as the solvent, and the chemical shift δ and coupling constant J were expressed in ppm and Hz, respectively.

[0057] The following examples are intended to illustrate the present invention in detail but are not intended to limit the present invention.

[0058] Example 1

[0059] Catalyst preparation

[0060] (1) Preparation of COP vector

[0061] PA-MA-1: 80.3 g of PA, 113.0 g of MA and 1.8 g of NaOH were added to 300 g of water and stirred at 80° C. for 15 min, which was recorded as solution A1.

[0062] 22.8 g of Poloxamer F127 was dissolved in 73.8 g of 36 wt % hydrochloric acid, and the solution was added to an alcohol-water mixed solution containing 196 g of ethylene glycol and 150 g of water. The mixture was stirred at room temperature for 2 h to obtain solution B1.

[0063] Solution B was poured into solution A1, and the mixed solution was quickly transferred to an autoclave and heated to 150°C at a rate of 2°C / min. The temperature was maintained for 24 hours. After cooling to room temperature, the mixture was filtered to obtain a yellow solid. The product was refluxed with 100 ml of ethanol for 6 hours and then filtered. This was repeated three times. The resulting COP support was designated PA-MA-1.

[0064] PA-MA-2: 35.0 g of PA, 41.7 g of MA and 1.6 g of sodium ethoxide were added to 180 g of water and stirred at 80° C. for 15 min. This was recorded as solution A2.

[0065] 19.5 g of Poloxamer 407 was dissolved in 4.9 g of 85 wt % phosphoric acid, and the solution was added to an alcohol-water mixed solution containing 58.9 g of propylene glycol and 50 g of water. The mixture was stirred at room temperature for 2 h to obtain solution B2.

[0066] Solution B2 was poured into solution A2, and the mixed solution was quickly transferred to an autoclave and heated to 150°C at a rate of 2°C / min. The temperature was maintained for 24 hours. After cooling to room temperature, the mixture was filtered to obtain a yellow solid. The product was refluxed with 80 ml of methanol for 6 hours and then filtered. This was repeated three times. The resulting COP support was designated PA-MA-2.

[0067] (2) Preparation of catalyst

[0068] 15g of PA-MA-1 was added to a mixture of 5.1g of 1,3-propane sultone and 176.8g of toluene at 110°C and refluxed for 24 hours. After the mixture was cooled to room temperature, 6.3g of CF3SO3H was added and the mixture was reacted at 60°C for 24 hours. After standing for 24 hours, the mixture was centrifuged and filtered, and washed three times with 50ml of dichloromethane. The resulting solid product was oven-dried at 80°C for 12 hours. The final product is designated [CN][OTf]-PA-MA-1.

[0069] 40.2 g of PA-MA-1 was added to a mixture of 8.1 g of 1,3-propane sultone and 758.7 g of toluene at 100°C and refluxed for 24 hours. After the mixture was cooled to room temperature, 16.1 g of CF3SO3H was added and the mixture was reacted at 70°C for 48 hours. After standing for 24 hours, the mixture was centrifuged and filtered, and washed three times with 50 ml of dichloromethane. The resulting solid product was oven-dried at 100°C for 12 hours. The final product is designated [CN][OTf]-PA-MA-2.

[0070] 28.9 g of PA-MA-2 was added to a mixture of 3.0 g of 1,3-propane sultone and 590.3 g of toluene at 105°C and refluxed for 24 hours. After the mixture was cooled to room temperature, 5.8 g of CF3SO3H was added and the reaction was continued at 65°C for 36 hours. After standing for 48 hours, the mixture was centrifuged and filtered, and washed three times with 50 ml of dichloromethane. The resulting solid product was oven-dried at 90°C for 24 hours. The final product is designated [C3N][OTf]-PA-MA-3.

[0071] 16.3 g of PA-MA-2 was added to a mixture of 1.8 g of 1,4-butane sultone and 805.3 g of toluene at 110°C and refluxed for 24 hours. After the mixture was cooled to room temperature, 0.8 g of CF3SO3H was added and the mixture was reacted at 70°C for 48 hours. After standing for 48 hours, the mixture was centrifuged and filtered, and washed three times with 50 ml of dichloromethane. The resulting solid product was oven-dried at 100°C for 48 hours. The final product is designated [CN][OTf]-PA-MA-4.

[0072] Example 2

[0073] Add 74.5g of ethylene glycol and 7.3g of n-hexanol into the reactor, add 12.2g of catalyst

[0074] [C3N][OTf]-PA-MA-1, 244.3 g of tridecanedioic acid was added with stirring, and 36.6 g of toluene was added. The mixture was stirred and heated to 110°C for reaction for 5 h. During this period, the water generated by the reaction in the water separator was separated. After the reaction was completed, the temperature was increased to evaporate the toluene. The reaction pressure of the system was slowly adjusted to 25 kPaA, and the temperature was increased to 210°C. Under these conditions, the reaction was carried out for 8 h. During this period, the reaction product musk T was evaporated to obtain 239.6 g of the product. The purity measured by GC was 96.37%, and the yield was 85.4%.

[0075] PMR: δ0.88–1.7(m,22H),2.3–2.5(t,4H),4.5(s,4H).

[0076] Example 3

[0077] Add 62.1g of ethylene glycol and 1.2g of n-octanol into the reactor, add 31.5g of catalyst

[0078] [C3N][OTf]-PA-MA-2, 244.1g of tridecanedioic acid was added with stirring, and 48.9g of ethylbenzene was added. The mixture was stirred and heated to 138°C for reaction for 8h. During this period, the water generated by the reaction in the water separator was separated. After the reaction was completed, the temperature was increased to evaporate the ethylbenzene. After the solvent was evaporated, the system reaction pressure was slowly adjusted to 20kPaA, and the temperature was increased to 180°C. The reaction was carried out under this condition for 10h. During this period, the reaction product musk T was evaporated to obtain 241.4g of product. The purity measured by GC was 93.6%, and the yield was 83.6%.

[0079] Example 4

[0080] 93.1 g of ethylene glycol and 12.2 g of 2-ethylhexanol were added to the reactor, 24.4 g of catalyst [C3N][OTf]-PA-MA-3 was added, 244.4 g of tridecanedioic acid was added under stirring, 48.7 g of toluene was added, and the mixture was stirred and heated to 105°C for 10 h. During this period, the water generated by the reaction in the water separator was separated. After the reaction was completed, the temperature was increased to evaporate the toluene. After the solvent was evaporated, the system reaction pressure was slowly adjusted to 30 kPaA, the temperature was increased to 150°C, and the reaction was carried out under these conditions for 6 h. During this period, the reaction product musk T was evaporated to obtain 234.0 g of the product. The purity measured by GC was 95.6%, and the yield was 82.8%.

[0081] Example 5

[0082] Add 80.7g of ethylene glycol and 6.1g of n-octanol into the reactor, add 1.2g of catalyst

[0083] [C4N][OTf]-PA-MA-2, 244.4 g of tridecanedioic acid was added with stirring, and 36.6 g of ethylbenzene was added. The mixture was stirred and heated to 135°C for reaction for 3 hours. During this period, the water generated by the reaction in the water separator was separated. After the reaction was completed, the temperature was increased to evaporate the ethylbenzene. After the solvent was evaporated, the system reaction pressure was slowly adjusted to 20 kPaA, and the temperature was increased to 250°C. Under these conditions, the reaction was carried out for 3 hours. During this period, the reaction product musk T was evaporated to obtain 236.4 g of the product. The purity measured by GC was 95.28%, and the yield was 83.3%.

[0084] Example 6

[0085] Add 74.5g of ethylene glycol, 7.0g of n-hexanol and 12.2g of catalyst into the reactor.

[0086] [C3N][OTf]-PA-MA-4, 244.3 g of tridecanedioic acid was added with stirring, and 35.1 g of recovered toluene was added. The mixture was stirred and heated to 110°C for 8 h. During this period, the water generated by the reaction in the water separator was separated. After the reaction was completed, the temperature was increased to evaporate the toluene. The reaction pressure of the system was slowly adjusted to 30 kPaA, and the temperature was increased to 220°C. The reaction was carried out under these conditions for 10 h. During this period, the reaction product musk T was evaporated to obtain 263.4 g of the product. The purity measured by GC was 94.50%, and the yield was 92.1%.

[0087] Comparative Example 1

[0088] Add 320.3g of tridecanedioic acid and 96.6g of ethylene glycol to the reactor. Then add 120.3g of ethylene glycol. Heat to 170℃ and react for 3h. Slowly adjust the pressure of the reactor to 0.7kPaA, and add 0.6g of isopropyl titanate and 4.0g of ethylene glycol to the reaction. Heat to 220℃ and then add 55.1g of ethylene glycol, and continue to heat to 245℃. React for 5h. After the reaction is complete, add 50.0g of 10wt% sodium sulfate solution for washing. The crude product is distilled at a temperature of 245℃ and a vacuum of 100PaA to obtain 298.9g of musk T. GC measured the purity to be 90.50% and the yield to be 76.3%.

[0089] Comparative Example 2

[0090] Catalyst preparation

[0091] Weigh 15.3 g of aluminum carbonate, 10.2 g of p-toluenesulfonic acid, 9.8 g of silicotungstomolybdic acid, and 5.1 g of anhydrous copper sulfate into 63.5 g of water and stir until completely dissolved. Weigh 70 g of activated carbon and add it to the solution. Reflux for 8 hours, filter under reduced pressure, wash three times with 20 g of water, and dry in a 95°C oven for 24 hours.

[0092] Preparation of Musk T

[0093] 268.9 g of tridecanedioic acid and 103.0 g of ethylene glycol were added to the reactor. After nitrogen replacement, stirring was started and the temperature was raised to 180°C for reaction. The water generated by the reaction was condensed and entered the receiving tank. The polymerization reaction was completed after no water was generated. The pressure was slowly adjusted to 20 PaA and the temperature was slowly raised to 185°C to evaporate the excess ethylene glycol in the reactor. After the evaporation, the nitrogen was restored to normal pressure.

[0094] Under a nitrogen atmosphere, 27.3 g of the above-prepared catalyst was added to the reactor. The atmosphere was replaced with nitrogen three times. The vacuum was then slowly reduced to 100 PaA. The temperature was then raised, and the distillate was collected. As the reaction proceeded, the temperature was continuously increased until it reached 325°C. The reaction was terminated when the vapor phase temperature dropped and no distillate was produced. 235.2 g of distillate was collected, with a purity of 90.42% as determined by GC, for a yield of 71.5%.

Claims

1. A method for preparing musk T, characterized in that: Musk T is prepared by esterifying and depolymerizing tridecanedioic acid and ethylene glycol in the presence of a catalyst.

2. The preparation method according to claim 1, characterized in that A monohydric alcohol is also added during the reaction.

3. The preparation method according to claim 1 or 2, characterized in that The esterification reaction temperature is 100-150°C, preferably 110-140°C; the depolymerization reaction temperature is 150-250°C, preferably 180-220°C.

4. The preparation method according to any one of claims 1 to 3, characterized in that The molar ratio of tridecanedioic acid to ethylene glycol is 1:1-1:1.5, more preferably 1:1.1-1:1.2; Preferably, the monohydric alcohol is selected from one or more of n-hexanol, n-octanol, and 2-ethylhexanol; Preferably, the amount of the monohydric alcohol added is 0.5-5% of the molar amount of tridecanedioic acid, preferably 2.5-5%; Preferably, the catalyst is a sulfonic acid modified catalyst.

5. The preparation method according to any one of claims 1 to 4, characterized in that The preparation method of the catalyst comprises the following steps: (1) Preparation of COP vector (1-1) Paraformaldehyde (PA), melamine (MA), and an alkaline catalyst are added to water and mixed to react; (1-2) dissolving a nonionic surfactant in an acidic solution, adding the solution to an alcohol-water solution, mixing the solution evenly, and then adding the mixture to the reaction solution obtained in step (1-1), reacting the solution, cooling the solution to room temperature, and filtering the solution to obtain a carrier, which is represented by PA-MA; (2) Load The carrier PA-MA prepared in step (1) is added to a mixture of sultone and the first solvent to load the sultone on the carrier. Then, CF3SO3H is added to react. After the reaction is completed, the catalyst is separated, washed, and dried to obtain the catalyst.

6. The preparation method according to claim 5, characterized in that The added alkaline catalyst includes but is not limited to sodium hydroxide, potassium hydroxide, sodium ethoxide, sodium methoxide, and aqueous ammonia; Preferably, the reaction temperature of step (1-1) is 80-100°C; Preferably, in step (1-1), the amount of water added is 1-10 times the mass of paraformaldehyde.

7. The preparation method according to claim 5, characterized in that The acidic solution is an acid solution, and the acid includes one or more of hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, p-toluenesulfonic acid, and aminosulfonic acid; Preferably, the alcohol in the alcohol-water solution includes but is not limited to one or more of methanol, ethanol, ethylene glycol, propylene glycol, and glycerol.

8. The preparation method according to claim 5, characterized in that Step (1-2) and the reaction solution obtained in step (1-1) are reacted at 150° C. to 180° C.; Preferably, the carrier obtained by filtration is refluxed with ethanol; Preferably, in step (1-1), the mass ratio of paraformaldehyde to melamine is 1:(1.2-1.8); Preferably, in step (1-1), the molar ratio of alkali to melamine is (0.03-0.06):1; Preferably, in step (1-1), the amount of water added is 2-5 times the mass of paraformaldehyde; Preferably, in step (1-2), the mass ratio of surfactant to melamine is (0.2-0.6):1; Preferably, the nonionic surfactant is one or more of a polyether surfactant and a polyether-polyester block surfactant, preferably a copolymer of ethylene oxide and propylene oxide, a block copolymer of polyoxypropylene glycol and ethylene oxide, more preferably Poloxamer 407 and Poloxamer F127; Preferably, in step (1-2), the molar ratio of acid to melamine is (0.5-1.0):1; Preferably, in step (1-2), the molar ratio of alcohol to melamine is (2-5):1; Preferably, in step (1-2), the mass ratio of water to ethylene glycol is (0.5-1):1; In step (2), the mass ratio of sultone to PA-MA is (0.1-0.5):1; Preferably, the sultone is selected from 1,4-butane sultone or 1,3-propane sultone; After adding sultone in step (2), heating under reflux for 24-48h for loading; In step (2), the mass ratio of CF3SO3H to PA-MA is (0.05-0.5):1; In step (2), the first solvent is selected from toluene or ethylbenzene, and the mass ratio of the added solvent to the PA-MA is (20-50):1; Preferably, in step (2), the reaction temperature after adding CF3SO3H is 60-70°C, and the reaction time is 24-48h; after the reaction is completed, the separated product is washed with dichloromethane; Preferably, in step (2), the drying temperature is 80-100° C., and the drying time is 24-48 hours.

9. The preparation method according to any one of claims 5 to 8, characterized in that In the preparation method of musk T, the amount of catalyst added is 0.5wt%-20wt% of the mass of the raw material tridecanedioic acid, preferably 2wt%-10wt%.

10. The preparation method according to any one of claims 5 to 9, characterized in that: In the preparation method of musk T, the reaction is carried out in a second solvent, which is toluene or ethylbenzene; Preferably, the amount of the second solvent added is 10%-20% of the mass of the tridecanedioic acid; Preferably, the esterification reaction can be carried out under normal pressure; Preferably, the reaction time of the esterification stage is 3h-10h, preferably 3-5h; Preferably, the pressure in the depolymerization stage is 20-30 PaA; Preferably, the reaction time of the depolymerization stage is 3 h to 10 h, preferably 5 to 8 h.