Compound or salt thereof, hair treatment composition, and method

Abstract

To provide a compound or salt thereof that exhibits a high hair-improving effect.SOLUTION: The invention provides a compound represented by formula (1), or a salt thereof.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a compound or a salt thereof that has a hair quality improving effect, a hair treatment composition containing the compound or a salt thereof as an active ingredient, and a method for producing the compound or a salt thereof. [Background technology]

[0002] For the purpose of improving hair condition, there have been disclosed hair treatment compositions containing a complex of dicarboxylic acid and thiols as an active ingredient (see Patent Document 1), and hair cosmetics containing a complex of aminothiols and organic acids as an active ingredient (see Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7232484 [Patent Document 2] Patent No. 7285494 Summary of the Invention [Problem to be solved by the invention]

[0004] There has been a demand for a compound or a salt thereof that exhibits a high hair quality improving effect. In particular, Patent Document 1 discloses a composition containing a complex of a dicarboxylic acid and a thiol, but from the common general technical knowledge, it is believed that the composition contains multiple complexes, and it was not clear which compound contained in the composition exhibits the hair quality improving effect. At the same time, there has also been a demand for a production method that can efficiently obtain a compound or a salt thereof that exhibits a high hair quality improving effect.

[0005] That is, the first problem to be solved by the present invention is to provide a compound or a salt thereof that exhibits a high hair quality improving effect, and the second problem to be solved by the present invention is to provide an efficient method for producing a compound or a salt thereof that exhibits a high hair quality improving effect. [Means for solving the problem]

[0006] That is, the present invention relates to a compound represented by the following formula (1) and / or (2) or a salt thereof.

[0007] [ka]

[0008] [ka]

[0009] The salt of the compound represented by formula (1) and / or the salt of the compound represented by formula (2) may be a salt of the above compound with one or more ions selected from the group consisting of sodium ions, lithium ions, magnesium ions, calcium ions, potassium ions, and ammonium ions.

[0010] Furthermore, the salt of the compound represented by formula (1) and / or the salt of the compound represented by formula (2) may be a salt of the above compound with one or more ions selected from the group consisting of chloride ion, bromide ion, fluoride ion, iodide ion, carbonate ion, bicarbonate ion, and phosphate ion.

[0011] The present invention also provides a crystallized form of the above-mentioned compound or a salt thereof. That is, the present invention provides a crystal of the above-mentioned compound or a salt thereof.

[0012] The compound or salt thereof of the present invention may be the above-mentioned compound or salt thereof used for hair treatment. The present invention may also be the use of the above-mentioned compound or salt thereof in the production of a hair treatment composition. The present invention provides a hair treatment composition containing the above-mentioned compound or salt thereof as an active ingredient.

[0013] Another aspect of the present invention provides a method for producing a compound or a salt thereof, comprising the steps of reacting a dicarboxylic acid with a thiol in an aqueous solution to obtain a reaction solution, mixing the reaction solution with an organic solvent to obtain a mixture, and obtaining an organic solvent fraction containing the compound or a salt thereof from the mixture.

[0014] The step of reacting a dicarboxylic acid with a thiol in an aqueous solution to obtain a reaction solution may be a step of reacting the dicarboxylic acid with the thiol at a molar ratio of thiol / dicarboxylic acid of 1.5 to 4.5.

[0015] The organic solvent may be a lower alcohol, which may be one or more selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol, isopropyl alcohol, butanol, pentanol, propylene glycol, and derivatives thereof.

[0016] The method may further comprise the steps of removing the organic solvent from the organic solvent fraction and obtaining a crystallized compound or a salt thereof.

[0017] Another aspect of the present invention provides a method for obtaining the dicarboxylic acid by the steps of: reacting 1,2-benzenediol with ozone in the presence of an organic solvent and an alkali to obtain a reaction solution; removing the organic solvent from the reaction solution; and obtaining a salt of the dicarboxylic acid and the alkali.

[0018] Here, the organic solvent during the reaction of 1,2-benzenediol with ozone may be a cooled organic solvent, and may be at a temperature of -30°C to -80°C.

[0019] In the present invention, the dicarboxylic acid may be muconic acid and the thiol may be cysteamine. [Effects of the Invention]

[0020] The compound or salt thereof of the present invention provides hair with a high hair quality improving effect, such as curl retention. In particular, it has been confirmed that Compound 1 provides hair with significantly more slipperiness and smoothness than existing hair treatments. Furthermore, the production method of the present invention can efficiently obtain a compound or salt thereof that exhibits a high hair quality improving effect. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 shows a chromatogram of the product obtained in the example. [Figure 2] FIG. 1 shows the results of NMR analysis of Compound 1 obtained in an example. [Figure 3] These are photographs of hair treated with Compound 1 and Compound 2. The photograph on the left shows the condition before drooping, and the photograph on the right shows the condition after drooping for 1 hour. In the photograph, "B" indicates blank, "1" indicates hair treated with Compound 1, and "2" indicates hair treated with Compound 2. [Figure 4] 1 shows the results of measuring the coefficient of friction of hair treated with Compound 1 and Compound 2. "GA" in the figure represents the measured value of hair treated with an acid heat treatment using glyoxylic acid. Groups marked with different letters on the graph indicate that statistically significant differences were observed at a p-value of <0.05 using the Bonferroni method after one-way analysis of variance. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention relates to a compound or a salt thereof that has a hair quality improving effect, a hair treatment composition containing the compound or a salt thereof as an active ingredient, and a method for producing the compound or a salt thereof. The present invention will be described in detail below based on the following embodiments, but the present invention is not limited to these embodiments.

[0023] The compound of the present invention or a salt thereof is a compound or a salt thereof represented by the following formula (1) and / or (2): The compound of the present invention is one of several compounds obtained by the reaction of muconic acid and cysteamine.

[0024] [ka]

[0025] [ka]

[0026] Although a composition containing a complex obtained by reacting muconic acid and cysteamine has been known, since the composition contains multiple compounds, it was not clear which compound among them exhibits a hair quality improving effect. As shown in the examples below, it has been confirmed that the above compounds exhibit a significant hair quality improving effect. In particular, it has been revealed that the compound represented by formula (1) provides higher slipperiness and smoothness to hair than the compound represented by formula (2).

[0027] One embodiment of the salt of the compound of the present invention is a salt formed by bonding a carboxyl group in the compound of the present invention with a cation, specifically, sodium ion, lithium ion, magnesium ion, calcium ion, potassium ion, ammonium ion, etc.

[0028] Another embodiment of the salt of the compound of the present invention is a salt formed by bonding an amino group in the compound of the present invention with an anion, such as a chloride ion, bromide ion, fluoride ion, iodide ion, carbonate ion, bicarbonate ion, or phosphate ion.

[0029] Another aspect of the present invention provides a method for producing the aforementioned compound or a salt thereof. One embodiment of the production method of the present invention comprises the following steps (1) and (2): (1) a step of obtaining a dicarboxylic acid from 1,2-benzenediol, and (2) a step of obtaining the aforementioned compound or a salt thereof from a dicarboxylic acid and a thiol.

[0030] The step (1) of obtaining a dicarboxylic acid from 1,2-benzenediol includes the steps of reacting 1,2-benzenediol with ozone in the presence of an organic solvent and an alkali to obtain a reaction solution, removing the organic solvent from the reaction solution, and obtaining a salt of the dicarboxylic acid with the alkali, where the dicarboxylic acid may be muconic acid.

[0031] Muconic acid is produced when 1,2-benzenediol is reacted with ozone, but when this muconic acid further reacts with excess ozone, the muconic acid is decomposed to produce formic acid. However, in this step, because an alkali is present in the reaction solution, the muconic acid immediately after production reacts with the alkali, forming muconate and precipitating. The precipitated muconate is in a state where it is difficult to come into contact with ozone, and the decomposition reaction to produce formic acid is suppressed.

[0032] The alkali used in this step is not limited as long as it can bond with the carboxyl group of muconic acid, and may contain cations such as sodium ions, lithium ions, magnesium ions, calcium ions, potassium ions, and ammonium ions, and more specifically, hydroxides such as sodium hydroxide, lithium hydroxide, magnesium hydroxide, calcium hydroxide, potassium hydroxide, and ammonium hydroxide.

[0033] The concentration of the alkali in the reaction solution is not limited as long as it is a concentration at which the alkali and muconic acid form a salt, and specifically, the concentration of the alkali is 1 to 20% by weight, and can be 10 to 15% by weight.

[0034] In another embodiment of the present invention, the organic solvent is cooled to react 1,2-benzenediol with ozone under cooling. This increases the solubility of ozone in the reaction solution, allowing muconic acid to be obtained in high yield. The cooling temperature for the organic solvent is not limited, but is preferably from -30°C to -80°C, and more preferably from -40°C to -50°C.

[0035] The organic solvent used in this step is not limited as long as it does not solidify under cooling. The organic solvent used has a relative dielectric constant of 10 to 50 at room temperature, and more preferably 15 to 25.

[0036] The organic solvent may be a lower alcohol, and specific examples thereof include one or more selected from methanol, ethanol, 1-propanol, 2-propanol, isopropyl alcohol, butanol, pentanol, propylene glycol, and derivatives thereof.

[0037] In the step of removing the organic solvent from the reaction solution, the organic solvent can be removed from the reaction solution by a known method. Specific examples include a method of separating the organic solvent in the reaction solution from a precipitate containing muconate by centrifugation, filtration, etc., and a method of separating the organic solvent from the precipitate containing muconate by reducing the pressure and / or heating the reaction solution. Removing the organic solvent yields a precipitate containing a salt of muconic acid and an alkali.

[0038] Another aspect of the production method of the present invention includes a step of mixing the obtained salt of muconic acid with an alkali metal in an aqueous solution with an acid to obtain liberated muconic acid. The acid used here is not limited, but examples include hydrochloric acid, sulfuric acid, phosphoric acid, and nitric acid.

[0039] Step (2) of obtaining the compound or a salt thereof from a dicarboxylic acid and a thiol includes the steps of reacting the dicarboxylic acid with the thiol in an aqueous solution to obtain a reaction solution, mixing the reaction solution with an organic solvent to obtain a mixture, and obtaining an organic solvent fraction containing the compound or a salt thereof from the mixture.

[0040] A complex of a dicarboxylic acid and a thiol is soluble in water but insoluble in organic solvents such as lower alcohols. It has been found that a precipitate containing a crystallized complex of a dicarboxylic acid and a thiol can be obtained by adding an organic solvent in which the complex is insoluble to an aqueous solution in which a dicarboxylic acid and a thiol have reacted and mixing the organic solvent.

[0041] The organic solvent used in this step is not limited as long as it is a solvent in which the complex is insoluble, but is preferably a lower alcohol, such as methanol, ethanol, 1-propanol, 2-propanol, isopropyl alcohol, butanol, pentanol, propylene glycol, or a derivative thereof.

[0042] In the step of mixing the reaction solution with the organic solvent to obtain a mixture, the volume of the organic solvent to be mixed is preferably equal to or greater than that of the reaction solution. Specifically, the volume of the organic solvent to be mixed may be 1 to 20 times, 2 to 10 times, or about 5 times the volume of the reaction solution.

[0043] The step of obtaining an organic solvent fraction containing the compound or a salt thereof from the mixture may be a step of removing a water-soluble fraction from the mixture. When the mixture is allowed to stand for a certain period of time or when the mixture is centrifuged, the mixture separates into an aqueous layer and an organic solvent layer, and the aqueous layer can be removed.

[0044] In another embodiment, the steps of mixing the reaction solution with an organic solvent to obtain a mixture and obtaining an organic solvent fraction containing the compound or a salt thereof from the mixture are repeated multiple times. This embodiment includes the steps of mixing an organic solvent with the organic solvent fraction obtained in the step of obtaining an organic solvent fraction containing the compound or a salt thereof to obtain a second mixture, and obtaining an organic solvent fraction containing the compound or a salt thereof from the second mixture.

[0045] In one embodiment of the step of reacting a dicarboxylic acid with a thiol in an aqueous solution to obtain a reaction solution, the thiol and the dicarboxylic acid are reacted at a molar ratio of thiol / dicarboxylic acid of 1.5 or more to obtain a reaction solution, where the dicarboxylic acid may be muconic acid and the thiol may be cysteamine.

[0046] As will be shown in the Examples below, the compound represented by formula 1 exhibits a higher hair quality improving effect than the compound represented by formula 2. Therefore, a production method for obtaining the compound represented by formula 1 in high yield is desired.

[0047] The compound shown in Formula 1 is a compound obtained by combining muconic acid and cysteamine at a molar ratio of cysteamine / muconic acid = 1. However, since a cysteamine dimer may be formed during the reaction between muconic acid and cysteamine, mixing at a molar ratio of cysteamine / muconic acid = 1 may result in a low yield of the compound shown in Formula 1.

[0048] As shown in the Examples below, the compound represented by Formula 1 was obtained in a yield of about 60 mol % or more by reacting cysteamine with muconic acid at a molar ratio of cysteamine / muconic acid of 1.5 or more. In another embodiment, this step is a step in which cysteamine and muconic acid are reacted at a molar ratio of cysteamine / muconic acid of 3.0 to 4.5 to obtain a reaction solution. In this embodiment, the compound represented by Formula 1 was obtained in a yield of about 75 mol % or more.

[0049] The reaction solution in this step may be weakly acidic to weakly basic, but is preferably weakly acidic to neutral, and the pH of the reaction solution is preferably 6 to 7. If the pH of the reaction solution is 8 or higher, the yield of the compound represented by formula 1 may decrease.

[0050] The present invention provides a hair treatment composition containing the above-mentioned compound as an active ingredient. The composition of the present invention contains the above-mentioned compound as an active ingredient, but may or may not contain other active ingredients besides the above-mentioned compound. This is because even if the composition does not contain other active ingredients besides the above-mentioned compound, it can still exhibit a hair quality improving effect as long as it contains at least the above-mentioned compound.

[0051] Here, the active ingredient other than the above-mentioned compounds refers to an ingredient that has some effect on hair when applied to hair, and specifically includes reducing agents other than thiols such as disulfide compounds and sodium sulfite, oxidizing agents such as sodium bromate and hydrogen peroxide, moisturizing agents such as hyaluronic acid, chondroitin sulfate, collagen, glycerin, xylitol, glucose, sucrose, amino acids, their derivatives, and their salts, thickeners such as xanthan gum, guar gum, and pectin, surfactants such as anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants, etc. Here, the active ingredient other than the above-mentioned compounds does not include ingredients that are not intended to have a direct effect on hair, such as antioxidants, preservatives, preservatives, fragrances, colorants, and pH adjusters.

[0052] Further, another embodiment of the present invention may be a hair straightener, a hair quality improving agent for dyeing and / or bleaching, a hair quality improving agent for wave perm and / or straight perm, a hair dye, a bleach, a shampoo, a hair treatment agent, a hair styling agent, a hair care agent and / or a hair growth agent, etc., containing the above-mentioned hair treatment composition. [Example]

[0053] The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[0054] Example 1. Identification of the compound of the present invention or its salt and its effect of improving hair quality

[0055] 2.0 g (14.07 mmol) of cis,cis-muconic acid was added to 7.0 mL of 4.0 mol / L aqueous NaOH solution, followed by the addition of 13.0 mL of water and stirring. 4.8 g (42.25 mmol) of cysteamine hydrochloride was then added and stirred. The pH was adjusted to approximately 6 with aqueous sodium hydroxide, and the mixture was heated to 100°C to react the muconic acid and cysteamine, and maintained at this temperature for a certain period of time.

[0056] Liquid chromatography mass spectrometry was performed under the following conditions to identify the compounds produced. Separation was performed in gradient mode with a water / acetonitrile mixed solvent as the eluent at a flow rate of 0.40 mL / min. A Waters octadecyl-bonded silica gel (ODS) column was used. Mass spectrometry was performed in negative ion mode (applied voltage -0.8 kV) to identify the compounds.

[0057] Figure 1 shows the chromatogram of the product obtained after a 90-minute reaction at 100°C. Two main components were observed: one that was rapidly produced 15 minutes after the start of the reaction and then decreased, and another that was present in small amounts after 15 minutes of reaction but increased for up to 3 hours. The main component of the former is the peak at 4.81 min in Figure 1, and the main component of the latter is the peak at 1.13 min.

[0058] The fractions with the peak at 1.13 min were collected, the solvent was distilled off, and the resulting powder was prepared. The powder was dissolved in heavy water and measured by NMR. The NMR analysis results are shown in Figure 2. From the above, it was demonstrated that compound 1 can be obtained by the reaction of muconic acid and cysteamine. It was also suggested that compound 2 is generated as an intermediate product during the production of compound 1.

[0059] The hair quality improvement effects of Compound 1 and Compound 2 were compared. Compound 1 was prepared by reacting cis,cis-muconic acid and cysteamine hydrochloride in a molar ratio of 1:3 under the same conditions as above, and the resulting reaction solution was separated using an octadecyl-bonded silica gel (ODS) column with a mobile phase (liquid A: ultrapure water, liquid B: acetonitrile), and the fractions collected approximately 3 minutes after the start of separation. Compound 2 was prepared by mixing muconic acid and cysteamine hydrochloride in a molar ratio of 1:1 under the same conditions as above, and the resulting reaction solution was separated in the same way as above, and the fractions collected approximately 3.5 minutes after the start of separation.

[0060] Compound 1 has a larger number of dissociating groups than Compound 2, and Compound 1 is more hydrophilic than Compound 2. Therefore, it has been confirmed that Compound 1 and Compound 2 can be separated by collecting fractions with the above elution times. The solvent in the collected fractions was distilled off under reduced pressure to obtain a powder, which was weighed and then dissolved in water to adjust the concentration to the desired level.

[0061] Thirty to forty strands of bleached human hair (average length 25 cm) were bundled together, and the length L was measured. The strands were immersed in a solution containing 0.1% by weight of either Compound 1 or Compound 2 for 5 minutes, and excess water was wiped off. The hair bundle was wound around a rod 8 cm long and 15 to 20 mm in diameter and left to stand for 15 minutes. It was then heated for 5 minutes using a hair dryer so that the surface temperature of the hair bundle reached 80°C, and the length L0 was measured. The hair bundle was left hanging for 1 hour in an environment with a temperature of 40°C and a humidity of 88%, and the length L t The retention rate of the curl formed on the hair bundle was calculated based on the following formula: Purified water was used as a blank instead of the solution containing Compound 1 or 2.

[0062]

number

[0063] A comparison of the hair bundles before and after the application is shown in Figure 3. The curl retention rate for the blank was 18.5%, while that for Compound 1 was 37.7% and that for Compound 2 was 37.5%, confirming the remarkable effect of these compounds in improving hair quality.

[0064] Strands of commercially available bleached human hair (average length 10 cm) were immersed in a solution containing 0.1 wt% of Compound 1 or Compound 2 for 5 minutes, wiped to remove excess water, and heated at 80°C for 5 minutes using a hair dryer. Purified water was used as a blank instead of the solution containing Compound 1 or 2. For comparison, hair treated with acid heat treatment using glyoxylic acid was also used. Ten strands of hair from each treatment were arranged at 1 mm intervals on a 26 mm x 70 mm glass slide. The coefficient of friction was measured using a friction tester TL201Tt (manufactured by Trinity Labs) in a glove box maintained at 25°C and 50±10% relative humidity.

[0065] The mean friction coefficient (MIU) and mean deviation (MMD) obtained by measuring three samples under each condition are shown in Figure 4. Generally, MIU indicates the slipperiness of hair, with a smaller MIU value indicating smoother hair, and MMD indicates roughness, with a smaller MMD value indicating smoother hair. This experiment confirmed the improving effects of Compound 1 and Compound 2 on hair. In particular, Compound 1 was shown to provide significant slipperiness and smoothness to hair compared to Blank and existing hair treatments.

[0066] Example 2. Preparation of a complex of muconic acid and cysteamine In this example, Compound 1 and Compound 2 were prepared by the following steps: (1) obtaining muconic acid from 1,2-benzenediol, and (2) obtaining Compound 1 and Compound 2 from muconic acid and cysteamine hydrochloride.

[0067] (1) Obtaining muconic acid from 1,2-benzenediol 1.1 g of 1,2-benzenediol and 12 g of sodium hydroxide were dissolved in 100 mL of 2-propanol. Ozone gas was bubbled through the solution for 6 hours under a temperature of minus 40 degrees. The 2-propanol was distilled off under reduced pressure, and the resulting solution was converted into an aqueous solution. Sulfuric acid was added to precipitate muconic acid. cis,cis-muconic acid was obtained in a yield of 53.6% by weight based on the weight of 1,2-benzenediol.

[0068] (2) Obtaining Compounds 1 and 2 from Muconic Acid and Cysteamine Hydrochloride A solution was obtained by dissolving 1.0 g of muconic acid and 2.37 g of cysteamine hydrochloride in 20 mL of purified water. The pH of the solution was adjusted to 7 with the addition of aqueous ammonia, and the solution was heated to 80°C and maintained for 3 hours. This solution was analyzed, confirming that Compound 1 had been obtained. A five-fold volume of 2-propanol was added to the solution and stirred. The supernatant was removed by decantation, and the same volume of 2-propanol was added again, stirred, and the supernatant was removed. Compound 1 precipitated using this method, and the mixture was dried overnight at 40°C under reduced pressure (a differential pressure reading minus 0.8 MPa) to obtain crystallized Compound 1 (i.e., crystals of Compound 1).

[0069] In another example, purified water was added to 1.0 g (7.0 mmol) of muconic acid and stirred. Furthermore, 1.2 g (10.5 mmol), 2.4 g (21.1 mmol), or 3.6 g (31.6 mmol) of cysteamine hydrochloride was added, and the pH was adjusted to 7.4 with aqueous ammonia. The solution was heated to 80°C, and the reaction solution was sampled after 30 minutes, 1 hour, 3 hours, and 6 hours. The sampled reaction solution was diluted 100,000 times with purified water, and MS spectra were measured. The yield (mol%) of compound 1 was calculated based on a previously prepared calibration curve. Similarly, 2.4 g (21.1 mmol) of cysteamine hydrochloride was added to 1.0 g (7.0 mmol) of muconic acid, and the pH was adjusted to 6, 7, 8, or 9, and similar measurements were performed.

[0070] The yields (mol %) of Compound 1 obtained by the above method are shown in Tables 1 and 2. When cysteamine and dicarboxylic acid were mixed at a molar ratio of cysteamine / dicarboxylic acid = 1.5 to 4.5, a high yield of 62% or more was obtained after heating for 3 hours. Furthermore, it was confirmed that the pH during the reaction is preferably 6 to 7, and that the yield of Compound 1 decreases when the pH is 8 or higher.

[0071] [Table 1]

[0072] [Table 2]

Claims

1. A compound represented by the following formula (1) and / or (2) or a salt thereof: 【Chemical 1】 【Chemistry 2】

2. A compound represented by the following formula (1) or a salt thereof: 【Chemistry 3】

3. 10. The compound or salt thereof according to claim 1, which has been crystallized.

4. A salt of the compound of claim 1, A salt of the compound according to claim 1 with an ion selected from the group consisting of sodium ion, lithium ion, magnesium ion, calcium ion, potassium ion, ammonium ion, chloride ion, bromide ion, fluoride ion, iodide ion, carbonate ion, bicarbonate ion, and phosphate ion.

5. The compound or salt thereof according to claim 2, which has been crystallized.

6. A salt of the compound of claim 2, A salt of the compound according to claim 2 with an ion selected from the group consisting of sodium ion, lithium ion, magnesium ion, calcium ion, potassium ion, ammonium ion, chloride ion, bromide ion, fluoride ion, iodide ion, carbonate ion, bicarbonate ion, and phosphate ion.

7. A hair treatment composition comprising the compound or salt thereof according to any one of claims 1 to 6 as an active ingredient.

8. A hair treatment composition comprising the compound or salt thereof according to any one of claims 2, 4 and 6 as an active ingredient.

9. A method for producing the compound of claim 1 or a salt thereof, comprising: a step of reacting a dicarboxylic acid with a thiol in an aqueous solution to obtain a reaction solution; mixing the reaction solution with an organic solvent to obtain a mixture; obtaining an organic solvent fraction from the mixture, the organic solvent fraction comprising the compound or a salt thereof; A method comprising:

10. the dicarboxylic acid and the thiol are reacted at a molar ratio of thiol / dicarboxylic acid of 1.5 to 4.5 to obtain a reaction solution; 10. The method of claim 9.

11. The method of claim 9, wherein the organic solvent is a lower alcohol.

12. The lower alcohol is one or more selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol, isopropyl alcohol, butanol, pentanol, propylene glycol, and derivatives thereof. The method of claim 11.

13. removing the organic solvent from the organic solvent fraction; obtaining a crystallized compound or a salt thereof, 10. The method of claim 9.

14. The dicarboxylic acid a step of reacting 1,2-benzenediol with ozone in the presence of an organic solvent and an alkali to obtain a reaction solution; removing the organic solvent from the reaction mixture; obtaining a salt of the dicarboxylic acid and the alkali; obtained from 10. The method of claim 9.

15. 15. The method of claim 14, wherein the organic solvent during the reaction of 1,2-benzenediol with ozone is a chilled organic solvent.

16. 15. The method of claim 14, wherein the organic solvent is at minus 30°C to minus 80°C during the reaction of 1,2-benzenediol with ozone.

17. 17. The method of any one of claims 9 to 16, wherein the dicarboxylic acid is muconic acid.

18. 18. The method of claim 17, wherein the thiol is cysteamine.

Images