Method for synthesizing hydroquinone

Abstract

The invention discloses a synthetic method for preparing corresponding hydroquinone through normal-pressure hydrogenation of quinone. Hydroquinone is an important compound, widely exists in natural products with biological activity, and is an important precursor for synthesizing various medicines, agricultural chemicals, polymers and functional materials. The method for reducing the quinone compound into hydroquinone is a simple and direct method. Although many reducing agents, such as SnCl2, Zn, Fe, Na2S2O4, NaBH4, polymethylhydrosiloxane (PMHS), have been used for this conversion, these processes are often affected by the use of stoichiometric or excess reagents, violent reaction conditions, and the formation of large amounts of waste. The hydrogenation reaction of quinone with H2 is obviously the most ideal way to achieve this conversion because it has high atomic efficiency and environmental friendliness. However, hydrogenation often needs high-pressure equipment or high temperature, so that the application potential is greatly limited. Accordingly, we we wish to exhibit a process for the hydrogenation of quinone to hydroquinone under atmospheric pressure.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic synthetic chemistry, and particularly relates to a synthesis method for preparing corresponding hydroquinones by hydrogenation of quinones under normal pressure. Background Art

[0002] Hydroquinones are a class of important compounds and are widely present in bioactive natural products such as glycopeptin, flavonol glycosides, doxorubicin hydrochloride, rifampicin, carnosic acid, hematoxylin, etc. (a) Wang, K.; Bao, L.; Zhou, N.; Zhang, J.J.; Liao, M.F.; Zheng, Z.Y.; Wang, Y.J.; Liu, C.; Wang, J.; Wang, L.F. J. Med. Chem. 2018, 61, 3609 - 3625. (b) Wang, Y.; Singh, A.P.; Nelson, H.N. et a1. J. Agric. Food Chem. 2016, 64, 7931 - 7939. (c) Colombo, E.; E.M.; S.; Polito L. et al. ACS Med. Chem. Lett. 2017, 8, 953 - 957. (d) Garg, A.; Alam, M.; Bai, S.; Dandawate, M. et al. ACS Pharmacol. Transl. Sci. 2023, 6, 253 - 269. (e) Cantrell, C.L.; Richheimer, S.L.; Nicholas, G.M.; Schmidt, B.K.; Bailey, D.T. J. Nat. Prod. 2005, 68, 98 - 100. (f) Lin, L.G.; Xie, H.; Li, H.L.; Tong, L.J. et al. J. Med. Chem. 2008, 51, 4419 - 4429.) Hydroquinone compounds are important precursors for the synthesis of various drugs, agrochemicals, polymers, and functional materials. (a) Ntungwe, E.N.; Stojanov, S.; Duarte, N. M. et al. ACS Med. Chem. Lett. 2022, 13, 4, 674 - 680. b) Chen, Y. R.; Chiou, R. Y. Y.; Lin, T. Y. et al. J. Agric. Food Chem. 2009, 57, 6, 2200 - 2205. c) Jin, H. J.; Chang W. K.; Son, S. U. ACS Appl. Energy Mater. 2022, 5, 11, 13149 - 13154. d) Shillingford, C.; Russell, C. W.; Burgess, I. B.; Aizenberg, J. ACS Appl. Mater. Interfaces 2016, 8, 7, 4314 - 4317.) The reduction of quinones provides a simple and direct method for the synthesis of hydroquinones, which has attracted extensive attention. Although many reducing agents, such as SnCl 2 , Zn, Fe, Na 2 S 2 O 4 , NaBH 4 , polymethylhydrosiloxane (PMHS) have been used for this transformation, these processes are often affected by the use of stoichiometric or excess reagents, drastic reaction conditions and the formation of a large amount of waste. The hydrogenation reaction of quinones with H 2 is obviously the most ideal way to achieve this transformation because of its high atom efficiency and environmental friendliness. However, hydrogenation often requires high - pressure equipment or high temperature, so its application potential is greatly limited.

[0003] Therefore, we hope to demonstrate a method for the hydrogenation of quinones to hydroquinones under atmospheric pressure. Summary of the Invention

[0004] The object of the present invention is to provide a synthetic method for the hydrogenation of quinones to corresponding hydroquinones under atmospheric pressure.

[0005] The present invention is achieved by the following technical solutions: A synthetic method for the hydrogenation of quinones to corresponding hydroquinones (Formula I) under atmospheric pressure.

[0006]

[0007] It includes various quinones (Formula II)

[0008]

[0009] Reacting with atmospheric pressure H 2 (Formula III)

[0010] H 2

[0011] III

[0012] The reaction occurs in the presence of an iridium complex catalyst, and its reaction general formula is

[0013]

[0014] Among them, R contains aromatic groups such as aryl, naphthyl, phenanthrene, etc., as well as other electron-donating groups such as methyl, ethyl, isopropyl, tert-butyl, methoxy, etc., and also contains electron-withdrawing groups such as chlorine, etc.

[0015] The invention is achieved through the following technical methods:

[0016] In a reaction vessel, quinone, a solvent, and a metal-ligand bifunctional iridium catalyst are added, and then a hydrogen gas balloon is connected. After the reaction mixture is in a test tube for several hours, it is cooled to room temperature, the solvent is removed by rotary evaporation, and then the target compound is obtained by column separation.

[0017] Among them, the metal-ligand bifunctional iridium catalyst has the following structure:

[0018]

[0019] The molar ratio of the catalyst dosage to quinone is 0.5 mol%; H 2 1 atm; the reaction is carried out in a test tube; the reaction time is 12 hours.

[0020] The present invention uses a metal-ligand bifunctional iridium complex to develop a reaction for synthesizing the corresponding dihydroxybenzene under H 2 atmospheric pressure. The reaction conditions are relatively mild, which promotes the development of bifunctional ligand catalysts and the development of hydrogen utilization. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 : is the 1H NMR spectrum of the product in Example 1; Figure 2 : is the 13C NMR spectrum of the product in Example 1; Figure 3 : is the 1H NMR spectrum of the product in Example 2; Figure 4 : is the 13C NMR spectrum of the product in Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0021] Some embodiments of the present invention are demonstrated by examples below, and should not be construed as limiting the scope of the present invention. Many improvements, variations, and changes can be made to the content disclosed in the present invention in terms of materials, methods, and reaction conditions. All these improvements, variations, and changes are definitely within the spirit and scope of the present invention.

[0022] Example 1:

[0023] Hydroquinone

[0024] Hydroquinone

[0025]

[0026] Add benzoquinone (108 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol%), and tert-amyl alcohol (4 mL) into a 25 mL Claisen tube successively, and connect an airbag filled with hydrogen at the side arm opening. After reacting at room temperature for 12 hours, remove the solvent by rotary evaporation, and then obtain the pure target compound through column chromatography (eluent: petroleum ether / ethyl acetate), yield: 95%

[0027] 1 H NMR (500 MHz, DMSO-d 6 ) δ 8.60 (s, 2H), 6.55 (s, 4H); 13 C{ 1 H}NMR (125 MHz, DMSO-d 6 ) δ 149.7, 115.7.

[0028] Example 2:

[0029] o-Methylhydroquinone

[0030] Methylhydroquinone

[0031]

[0032] Add methyl-p-benzoquinone (122 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol%), and tert-amyl alcohol (4 mL) into a 25 mL Claisen tube successively, and connect an airbag filled with hydrogen at the side arm opening. After reacting at room temperature for 12 hours, remove the solvent by rotary evaporation, and then obtain the pure target compound through column chromatography (eluent: petroleum ether / ethyl acetate), yield: 93%

[0033] 1 H NMR (500 MHz, DMSO-d 6 ) δ 8.43 (bs, 2H), 6.55 (d, J = 8.5 Hz, 1H), 6.47 (t, J = 2.5 Hz, 1H), 7.37 (dd, J = 8.5, 3 Hz, 1H), 2.03 (s, 3H); 13 C{ 1 H}NMR (125 MHz, DMSO-d 6 ) δ 149.6, 147.8, 124.5, 117.3, 115.2, 112.7, 16.2

[0034] Example 3:

[0035] 2,5-Dimethylhydroquinone

[0036] 2,4-Dimethyl N-(methyl-d 3 )benzenamine

[0037]

[0038] 2,5-Dimethyl-p-benzoquinone (136 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol%), and tert-amyl alcohol (4 ml) were successively added to a 25 mL Claisen tube, and an airbag filled with hydrogen was connected to the side arm. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 94%

[0039] 1 1H NMR (500 MHz, DMSO-d 6 ) δ 8.32 (s, 2H), 6.45 (s, 2H), 1.99 (s, 6H); 13 13C{ 1 1H}NMR (125 MHz, DMSO-d 6 ) δ 147.4, 121.1, 117.8, 15.7.

[0040] Example 4:

[0041] 2,6-Dimethylhydroquinone

[0042] 2,6-Dimethylhydroquinone

[0043]

[0044] 2,6-Dimethyl-p-benzoquinone (136 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol%), and tert-amyl alcohol (4 ml) were successively added to a 25 mL Claisen tube, and an airbag filled with hydrogen was connected to the side arm. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 91%

[0045] 1 1H NMR (500 MHz, DMSO-d 6 ) δ 8.46 (s, 1H), 7.41 (s, 1H), 6.31 (s, 2H), 2.06 (s, 6H); 13 13C{1 H}NMR(125 MHz, DMSO-d 6 ) δ 149.7, 145.4, 125.5, 114.5, 16.8.

[0046] Example 5:

[0047] Trimethylhydroquinone

[0048] Trimethylhydroquinone

[0049]

[0050] Trimethyl-p-benzoquinone (150 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol%) and tert-amyl alcohol (4 ml) were successively added to a 25 mL Kjeldahl flask, and an airbag filled with hydrogen was connected to the side arm. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 93%

[0051] 1 H NMR(500 MHz, DMSO-d 6 ) δ 8.37 (s, 1H), 7.34 (s, 1H), 6.36 (s, 1H), 2.05 (s, 3H), 2.04 (s, 3H), 1.98 (s, 3H)3; 13 C{ 1 H}NMR(125 MHz, DMSO-d 6 ) δ 147.8, 145.2, 124.6, 122.0, 120.1, 113.8, 16.7, 12.7, 12.0.

[0052] Example 6:

[0053] Tetramethylhydroquinone

[0054] TetraMethylhydroquinone

[0055]

[0056] Tetramethyl-p-benzoquinone (164 mg, 1 mmol), cat 1 (5.4 mg, 0.01 mmol, 1 mol%) and tert-amyl alcohol (4 ml) were successively added to a 25 mL Kjeldahl flask, and an airbag filled with hydrogen was connected to the side arm. After reacting at 60 °C for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 83%

[0057] 1 1H NMR (500 MHz, DMSO-d 6 ) δ 7.30 (s, 2H), 2.04 (s, 12H); 13 13C{ 1 1H} NMR (125 MHz, DMSO-d 6 ) δ 145.6, 121.3, 12.9.

[0058] Example 7:

[0059] 2-Isopropyl-5-methylhydroquinone

[0060] Thymohydroquinone

[0061]

[0062] Thymoquinone (164 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol%), and tert-amyl alcohol (4 ml) were successively added to a 25 mL Claisen tube, and an airbag filled with hydrogen was connected to the side arm. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 93%

[0063] 1 1H NMR (500 MHz, DMSO-d 6 ) δ 8.35 (s, 1H), 7.67 (s, 1H), 6.52 (s, 1H), 6.46 (s, 1H), 3.09 (m, 1H), 1.99 (s, 3H), 1.09 (d, J = 6.8 Hz, 6H); 13 13C{ 1 1H} NMR (125 MHz, DMSO-d 6 ) δ 147.8, 146.4, 132.0, 121.0, 117.1, 112.3, 26.1, 22.8, 15.7.

[0064] Example 8:

[0065] Tert-Butylhydroquinone

[0066] Tert-Butylhydroquinone

[0067]

[0068] tert-Butyl-p-benzoquinone (164 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol %), and tert-amyl alcohol (4 mL) were successively added to a 25 mL Claisen tube, and an airbag filled with hydrogen was connected to the side arm. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 91%

[0069] 1 H NMR (500 MHz, DMSO-d 6 ) δ 8.54 (s, 1H), 8.46 (s, 1H), 6.57 (d, J = 2.0 Hz, 1H), 6.55 (d, J = 8.5 Hz, 1H), 6.38 (dd, J = 8.3, 2.2 Hz, 1H), 1.30 (s, 2H), 4.00 (s, 9H); 13 C{ 1 H}NMR (125 MHz, DMSO-d 6 ) δ 149.4, 148.2, 136.0, 116.5, 113.5, 112.5, 34.2, 29.3.

[0070] Example 9:

[0071] 2,5-Di-tert-butylhydroquinone

[0072] 2,5-Di-tert-butylhydroquinone

[0073]

[0074] 2,5-Di-tert-butyl-p-benzoquinone (220 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol %), and tert-amyl alcohol (4 mL) were successively added to a 25 mL Claisen tube, and an airbag filled with hydrogen was connected to the side arm. After reacting at 60 °C for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 88%

[0075] 1 H NMR (500 MHz, DMSO-d 6 ) δ 8.38 (s, 2H), 6.58 (s, 2H), 1.28 (s, 18H); 13 C{ 1 H}NMR (125 MHz, DMSO-d 6 ) δ 147.5, 132.7, 114.6, 33.8, 29.4.

[0076] Example 10:

[0077] 2,6-Di-tert-butylhydroquinone

[0078] 2,6-Di-tert-butylhydroquinone

[0079]

[0080] 2,6-Di-tert-butylbenzoquinone (220 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol%), and tert-amyl alcohol (4 ml) were successively added to a 25 mL Kjeldahl flask, and an airbag filled with hydrogen was connected to the side arm. After reacting at 60 °C for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 90%

[0081] 1 H NMR (500 MHz, CDCl 3 ) δ 6.68 (s, 2H), 4.74 (s, 1H), 4.54 (s, 1H), 1.42 (s, 18H); 13 C{ 1 H}NMR (125 MHz, CDCl 3 ) δ 148.1, 147.6, 137.5, 111.8, 34.4, 30.1.

[0082] Example 11:

[0083] 2,5-Dimethoxyhydroquinone

[0084] 2,5-Dimethoxyhydroquinone

[0085]

[0086] 2,5-Dimethoxybenzoquinone (168 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol%), and tert-amyl alcohol (4 ml) were successively added to a 25 mL Kjeldahl flask, and an airbag filled with hydrogen was connected to the side arm. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 89%

[0087] 1 H NMR (500 MHz, DMSO-d 6 ) δ 8.24 (s, 2H), 6.43 (s, 2H), 3.65 (s, 6H); 13C{ 1 H} NMR (125 MHz, DMSO-d 6 ) δ 141.1, 138.7, 102.8, 56.4.

[0088] Example 12:

[0089] 2,6-Dimethoxyhydroquinone

[0090] 2,6-Dimethoxyhydroquinone

[0091]

[0092] 2,6-Dimethoxy-p-benzoquinone (168 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol%), and tert-amyl alcohol (4 ml) were successively added to a 25 mL Claisen tube, and an airbag filled with hydrogen was connected to the side arm. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 90%

[0093] 1 H NMR (500 MHz, DMSO-d 6 ) δ 8.78 (s, 1H), 7.46 (s, 1H), 6.03 (s, 2H), 3.67 (s, 6H); 13 C{ 1 H} NMR (125 MHz, DMSO-d 6 ) δ 149.9, 148.6, 128.0, 93.3, 55.7.

[0094] Example 13:

[0095] 2,3-Dimethoxy-5-methylhydroquinone

[0096] 2,3-DiMethoxy-5-Methyl-1,4-hydroquinone

[0097]

[0098] 2,3-Dimethoxy-5-methyl-p-benzoquinone (182 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol%), and tert-amyl alcohol (4 ml) were successively added to a 25 mL Claisen tube, and an airbag filled with hydrogen was connected to the side arm. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 92%

[0099] 1 1H NMR (500 MHz, DMSO) δ 8.43 (s, 1H), 7.96 (s, 1H), 6.31 (s, 1H), 3.71 (s, 3H), 3.70 (s, 3H), 2.01 (s, 3H); 13 13C{ 1 1H}NMR (125 MHz, DMSO-d 6 6) δ 142.5, 141.4, 140.6, 139.1, 119.4, 112.4, 60.6, 60.3, 15.9.

[0100] Example 14:

[0101] 2,5-Dichlorohydroquinone

[0102] 2,5-Dichlorohydroquinone

[0103]

[0104] 2,5-Dichlorobenzoquinone (177 mg, 1 mmol), cat 1 (5.4 mg, 0.01 mmol, 1 mol%), and tert-amyl alcohol (4 ml) were successively added to a 25 mL Claisen tube, and an airbag filled with hydrogen was connected to the side arm. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 74%

[0105] 1 1H NMR (500 MHz, DMSO-d 6 6) δ 9.79 (s, 2H), 6.91 (s, 2H); 13 13C{ 1 1H}NMR (125 MHz, DMSO-d 6 6) δ 145.9, 118.3, 117.1.

[0106] Example 15:

[0107] 2,6-Dichlorohydroquinone

[0108] 2,6-Dichlorohydroquinone

[0109]

[0110] 2,6 - Dichlorobenzoquinone (177 mg, 1 mmol), cat 1 (5.4 mg, 0.01 mmol, 1 mol %), and tert - amyl alcohol (4 ml) were successively added to a 25 mL Kjeldahl flask, and an airbag filled with hydrogen was connected to the side - tube mouth. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 83%

[0111] 1 H NMR (500 MHz, DMSO - d 6 ) δ 9.58 (s, 1H), 9.22 (s, 1H), 6.75 (s, 2H); 13 C{ 1 H}NMR (125 MHz, DMSO - d 6 ) δ 150.6, 141.6, 123.0, 115.3.

[0112] Example 16:

[0113] o - Phenylhydroquinone

[0114] Phenylhydroquinone

[0115]

[0116] o - Phenylbenzoquinone (184 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol %), and tert - amyl alcohol (4 ml) were successively added to a 25 mL Kjeldahl flask, and an airbag filled with hydrogen was connected to the side - tube mouth. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 91%

[0117] 1 H NMR (500 MHz, DMSO - d 6 ) δ 8.76 (s, 2H), 7.50 (d, J = 7.5 Hz, 2H), 7.37 (t, J = 7.5 Hz, 2H), 7.27 (t, J = 7.3 Hz, 1H), 6.74 (d, J = 8.6 Hz, 1H), 6.65 (d, J = 2.8 Hz, 1H), 6.58 (dd, J = 8.6, 2.8 Hz, 1H); 13 C{ 1 H}NMR (125 MHz, DMSO - d 6 ) δ 150.1, 146.7, 138.8, 129.0, 128.1, 127.9, 126.4, 116.8, 116.5, 115.0.

[0118] Example 17:

[0119] 2,5-Diphenylhydroquinone

[0120] 2,5-Diphenylhydroquinone

[0121]

[0122] 2,5-Diphenyl-1,4-benzoquinone (260 mg, 1 mmol), cat 1 (5.4 mg, 0.01 mmol, 1 mol%), and tert-amyl alcohol (4 ml) were successively added to a 25 mL Claisen tube, and an airbag filled with hydrogen was connected to the side arm opening. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 87%

[0123] 1 H NMR (500 MHz, DMSO-d 6 ) δ 8.94 (s, 2H), 7.56 (d, J = 6.9 Hz, 4H), 7.41 (d, J = 6.9 Hz, 4H), 7.30 (t, J = 7.1 Hz, 2H), 6.86 (s, 2H); 13 C{ 1 H}NMR (125 MHz, DMSO-d 6 ) δ 147.0, 138.4, 128.9, 128.0, 127.4, 126.5, 117.5.

[0124] Example 18:

[0125] 1,4-Dihydroxynaphthalene

[0126] 1,4-Dihydroxynaphthalene

[0127]

[0128] 1,4-Naphthoquinone (158 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol%), and tert-amyl alcohol (4 ml) were successively added to a 25 mL Claisen tube, and an airbag filled with hydrogen was connected to the side arm opening. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 94%

[0129] 1 H NMR (500 MHz, DMSO-d 6)δ9.31(s, 2H), 8.07(m, 2H), 7.47(m, 2H), 6.69(s, 2H); 13 C{ 1 H} NMR(125MHz, DMSO-d 6 )δ145.5, 125.4, 124.8, 122.0, 107.9.

[0130] Example 19:

[0131] 2-Methyl-1,4-naphthalenediol

[0132] 2-Methyl-1,4-naphthalenediol

[0133]

[0134] 2-Methyl-1,4-naphthoquinone (172 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol%) and tert-amyl alcohol (4 ml) were successively added to a 25 mL Claisen flask, and an airbag filled with hydrogen was connected to the side arm. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 89%

[0135] 1 1H NMR(500MHz, DMSO-d 6 )δ9.34(s, 1H), 8.24(s, 1H), 8.07(d, J = 8.4Hz, 1H), 8.00(d, J = 8.3Hz, 1H), 7.40(t, J = 7.1Hz, 1H), 7.34((t, J = 7.5Hz, 1H), 6.62(s, 1H), 2.27(s, 3H); 13 C{ 1 H} NMR(125MHz, DMSO-d 6 )δ145.9, 141.8, 126.6, 125.0, 123.8, 123.6, 121.9, 121.7, 118.8, 111.1, 16.6.

[0136] Example 20:

[0137] 3,5-Di-tert-butylbenzene-1,2-diol

[0138] 3,5-Di-tert-butylbenzene-1,2-diol

[0139]

[0140] 3,5-Di-tert-butyl-o-benzoquinone (220 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol %), and tert-amyl alcohol (4 ml) were successively added to a 25 mL Kjeldahl flask, and an airbag filled with hydrogen was connected to the side arm opening. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 96%

[0141] 1 H NMR (500 MHz, DMSO-d 6 ) δ 9.13 (s, 1H), 7.72 (s, 1H), 6.69 (s, 1H), 6.64 (s, 1H), 1.33 (s, 9H), 1.20 (s, 9H); 13 C{ 1 H} NMR (125 MHz, DMSO-d 6 ) δ 144.3, 141.4, 139.9, 134.5, 113.1, 110.2, 34.4, 33.8, 31.5, 29.5.

[0142] Example 21:

[0143] 1,2-Naphthol

[0144] 1,2-Dihydroxynaphthalene

[0145]

[0146] 1,2-Naphthoquinone (158 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol %), and tert-amyl alcohol (4 ml) were successively added to a 25 mL Kjeldahl flask, and an airbag filled with hydrogen was connected to the side arm opening. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 95%

[0147] 1 H NMR (500 MHz, DMSO-d 6 ) δ 9.33 (s, 1H), 8.87 (s, 1H), 8.06 (d, J = 8.4 Hz, 1H), 7.71 (d, J = 8.1 Hz, 1H), 7.37 (t, J = 7.3 Hz, 1H), 7.28 - 7.22 (m, 2H), 7.19 (d, J = 8.7 Hz, 1H); 13 C{ 1 H} NMR (125 MHz, DMSO-d 6). δ 140.1, 137.5, 128.4, 127.4, 125.8, 124.6, 122.7, 120.8, 118.8, 118.5.

[0148] Example 22:

[0149] 9,10-Phenanthrenediol

[0150] 9,10-Dihydroxyphenanthrene

[0151]

[0152] 9,10-Phenanthrenequinone (208 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol%), and tert-amyl alcohol (4 ml) were successively added to a 25 mL Claisen tube, and an airbag filled with hydrogen was connected at the side arm opening. After reacting at room temperature for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 90%

[0153] 1 1H NMR (500 MHz, DMSO-d 6 ) δ 8.98 (s, 2H), 8.71 (d, J = 7.3 Hz, 2H), 8.19 (d, J = 7.2 Hz, 2H), 7.61 (t, J = 6.4 Hz, 2H), 7.51 (t, J = 5.9 Hz, 2H); 13 13C{ 1 1H}NMR (125 MHz, DMSO-d 6 ) δ 134.4, 127.5, 126.3, 125.9, 124.1, 122.6, 121.3.

[0154] Example 23:

[0155] Tetra-tert-butylbiphenol

[0156] 2,2′,6,6′-Tetra-tert-butyl-4,4′-dihydroxybiphenyl

[0157]

[0158] 3,3′,5,5′-Tetra-tert-butyl-4,4′-biphenoquinone (408 mg, 1 mmol), cat 1 (5.4 mg, 0.01 mmol, 1 mol %), and 1,4-dioxane (4 ml) were successively added to a 25 mL Kjeldahl flask, and an airbag filled with hydrogen was connected to the side arm. After reacting at 60 °C for 12 hours, the solvent was removed by rotary evaporation, and then the pure target compound was obtained by column chromatography (eluent: petroleum ether / ethyl acetate), yield: 67%

[0159] 1 H NMR (500 MHz, DMSO-d 6 ) δ 7.19 (s, 4H), 6.92 (s, 2H), 1.41 (s, 36H); 13 C{ 1 H}NMR (125 MHz, DMSO-d 6 ) δ 152.8, 139.4, 133.5, 122.9, 34.5, 30.3.

[0160] Example 24:

[0161] Benzoquinone (108 mg, 1 mmol), cat 1 (2.7 mg, 0.005 mmol, 0.5 mol %), and tetrahydrofuran (4 ml) were successively added to a 25 mL Kjeldahl flask, and an airbag filled with hydrogen was connected to the side arm. After reacting at room temperature for 12 hours, it was cooled to room temperature. NMR yield: 100%

[0162] Example 25:

[0163] Benzoquinone (108 mg, 1 mmol), cat 1 (2.7 nmg, 0.005 mmol, 0.5 mol %), and 1,4-dioxane (4 ml) were successively added to a 25 mL Kjeldahl flask, and an airbag filled with hydrogen was connected to the side arm. After reacting at room temperature for 12 hours, it was cooled to room temperature. NMR yield: 100%

[0164] Example 26:

[0165] Benzoquinone (108 mg, 1 mmol), cat 2 (4.2 mg, 0.005 mmol, 0.5 mol %), and water (4 ml) were successively added to a 25 mL Kjeldahl flask, and an airbag filled with hydrogen was connected to the side arm. After reacting at room temperature for 12 hours, it was cooled to room temperature. NMR yield: 98%.

Claims

1. A method for preparing the corresponding hydroquinone (Formula I) by hydrogenation of quinone at normal pressure: is through quinone (Formula II) Reaction with atmospheric pressure hydrogen (Formula III) H2 III The reaction occurs in the presence of a metal-ligand bifunctional iridium catalyst, and the general reaction formula is: in, R includes aromatic groups selected from aryl, naphthyl, phenanthrene and the like, and other electron-donating groups such as methyl, ethyl, isopropyl, tert-butyl, methoxy and the like, and also includes electron-withdrawing groups such as chlorine and the like.

2. The synthetic method of diphenol according to claim 1, characterized in that The catalyst is selected from metal-ligand bifunctional iridium catalysts.

3. The synthetic method of diphenol according to claim 1, characterized in that The reaction was carried out under a H2 pressure of 1 atm.

4. The synthetic method of diphenol according to claim 1, characterized in that The amount of the catalyst used was 0.5 mol% relative to the quinone.

5. The synthetic method of diphenol according to claim 1, characterized in that The reaction time is 12 hours.

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