* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
With phosphoric acid In water at 59 - 81℃; for 2 h;
1) 3 parts by weight of phosphoric acid, 0.1 part by weight of water was poured into a stirring cylinder, and 6 parts by weight of hydroquinone was added to the stirring cylinder to carry out stirring;2) After stirring, the mixed solution was placed in a reaction kettle and heated to 59 ° C, and then the reaction vessel was charged with t-butanolCopies;3) heating to 81 ° C, the insulation for 2 hours to react;4) the reaction product by centrifugal separation, washing, dehydration after TBHQ crude;5) 1 part by weight of acid and 95 parts by weight of water were mixed and then heated. After heating to 81 ° C, 6.5 parts by weight of TBHQ was added and heated to 95 ° C with stirring.6) The solution of step 5) was centrifuged for the first time, the DTBHQ insoluble in water in the crude TBHQ was separated, and then the solution was cooled. When the solution was cooled to 45C or lower, the second centrifugation was carried out, and the obtained TBHQ crystal washing, dehydration, drying, that was TBHQ boutique.Wherein the drying in step 6) is carried out by pouring the wet TBHQ boutique into a vibrating screen sieve, laying the sieved TBHQ boutique on a drying tray, having a thickness of 5 cm and drying for 8 hours.The TBHQ was obtained, where the weight percentage of TBHQ was 99.9percent and the weight percentage of DTBHQ was 0.1percent.
Reference：
[1] Patent: CN103864580, 2016, B, . Location in patent: Paragraph 0095-0104
[2] Patent: US2511193, 1947, ,
[3] Patent: US2722556, 1952, ,
[4] Patent: CN105541560, 2016, A, . Location in patent: Paragraph 0011
[5] Patent: WO2018/214039, 2018, A1, . Location in patent: Page/Page column 12-15
[6] Patent: CN108929200, 2018, A, . Location in patent: Paragraph 0009; 0011; 0014; 0017
2
[ 3602-55-9 ]
[ 1948-33-0 ]
Yield
Reaction Conditions
Operation in experiment
99%
With (iPr4PCP)IrH4; hydrogen In toluene at 60℃; for 2 h;
General procedure: To a Teflon stoppered tube shaped glass ampoule ∼4.8mL in volume, 0.166mmol of the desired para-benzoquinone, a stir bar, and 0.25mL toluene containing 0.5mg iPrPCPIrH4 are added. Then the solution is freeze–pump-thaw degassed twice, and 1atm H2 applied. The sealed vessel is heated at a given temperature in an aluminum heat block with stirring for a prescribed period of time. When the reaction is ceased, volatiles are removed until only several μL toluene remain, and then the ampoule is quickly sealed. After this, 0.5mL THF-d8 is added and the solution transferred to an NMR tube for analysis.
Reference：
[1] Polyhedron, 2018, vol. 143, p. 209 - 214
[2] Agricultural and Biological Chemistry, 1988, vol. 52, # 11, p. 2843 - 2850
[3] Angewandte Chemie - International Edition, 2017, vol. 56, # 28, p. 8196 - 8200[4] Angew. Chem., 2017, vol. 129, # 28, p. 8308 - 8312,5
[5] Molecular Catalysis, 2018, vol. 456, p. 49 - 56
3
[ 88-18-6 ]
[ 3602-55-9 ]
[ 1948-33-0 ]
Yield
Reaction Conditions
Operation in experiment
97%
With dihydrogen peroxide In water; acetic acid at 50 - 60℃; for 1.25 h;
Preparation of 2-tert-butyl-1, 4-benzoquinone A mixture of 2-t-butylphenol (5 mmol) and Ti-superoxide catalyst (125 mg, 20percent w/w) in acetic acid (5 ml) was heated with stirring at 50-60 C under inert atmosphere. To this reaction mixture was added aq. 30percent H202 (20 mmol) drop wise over 15 min. and heated for 1 h. The catalyst was recovered by simple filtration and 2-tert-butyl-1, 4-benzoquinone formed (97percent) was separated by chromatographic purification.Table 1: Ti-superoxide (1) catalyzed oxidation of phenols to quinines and hydroquinones with aq. 30percent H202 : a Ex. Substrate t/h Conversion ProductU Selectivity (percent) c
Reaction1 Hydroquinone 110kg 116kg acetic acid tert-ester and sulfuric acid concentration of 50percent sulfuric acid 294kg added to the reaction kettle was warmed up to 85 ° C to a reaction for 8 hours to complete the reaction, cooling to 65 °C rear centrifugal filtration, filtrate recycling sulfuric acid, the resulting added 1 times warm water washing, the crude product of tert-butyl hydroquinone, wherein the tert-butyl hydroquinone content is 70percent.
Reference：
[1] Patent: CN105294403, 2016, A, . Location in patent: Paragraph 0027; 0028
5
[ 1634-04-4 ]
[ 123-31-9 ]
[ 2444-28-2 ]
[ 1948-33-0 ]
Reference：
[1] Applied Catalysis A: General, 2013, vol. 450, p. 34 - 41
6
[ 123-31-9 ]
[ 75-65-0 ]
[ 6669-13-2 ]
[ 2460-77-7 ]
[ 88-58-4 ]
[ 1948-33-0 ]
Yield
Reaction Conditions
Operation in experiment
48.8%
With porous pillared-zirconium phosphate functionalized with methyl group In 5,5-dimethyl-1,3-cyclohexadiene at 150℃; for 4 h; Autoclave
Alkylation of hydroquinone with tert-butanol was carried outin an autoclave equipped with a magnetic stirrer. Typically, 0.5 ghydroquinone, 1.0 g tert-butanol, and 0.20 g catalyst were addedto the autoclave, along with 2 g of xylene as a solvent. The reac-tion lasted 4 h under 150C. The products were analyzed witha gas chromatograph equipped with a SE-30 capillary column(30 m × 0.25 mm × 0.3 m) and a flame ionization detector. Thetemperature of the capillary column was set at 180C. The mainproducts were 2-tert-butyl hydroquinone (2-TBHQ), 2,5-di-tert-butyl hydroquinone (2,5-TBHQ), 2,5-di-tert-butyl benzoquinone(2,5-DTBBQ) and tert-butyl phenol ether (TBPE).
Reference：
[1] Journal of Molecular Catalysis A: Chemical, 2013, vol. 380, p. 84 - 89
[2] Chinese Journal of Catalysis, 2014, vol. 35, # 11, p. 1874 - 1882
7
[ 3602-55-9 ]
[ 100-46-9 ]
[ 1948-33-0 ]
Reference：
[1] Journal of the American Chemical Society, 1995, vol. 117, # 34, p. 8698 - 8706
Reference：
[1] Collection of Czechoslovak Chemical Communications, 2000, vol. 65, # 6, p. 924 - 940
17
[ 507-19-7 ]
[ 123-31-9 ]
[ 1948-33-0 ]
Reference：
[1] Journal of Organic Chemistry, 1984, vol. 49, # 22, p. 4161 - 4165
18
[ 123-31-9 ]
[ 115-11-7 ]
[ 88-58-4 ]
[ 2467-52-9 ]
[ 1948-33-0 ]
Reference：
[1] Australian Journal of Chemistry, 1997, vol. 50, # 5, p. 515 - 516
19
[ 66806-57-3 ]
[ 3602-55-9 ]
[ 1948-33-0 ]
Reference：
[1] Journal of Physical Chemistry, 1995, vol. 99, # 4, p. 1218 - 1227
20
[ 123-31-9 ]
[ 75-65-0 ]
[ 6669-13-2 ]
[ 2460-77-7 ]
[ 88-58-4 ]
[ 1948-33-0 ]
Yield
Reaction Conditions
Operation in experiment
48.8%
With porous pillared-zirconium phosphate functionalized with methyl group In 5,5-dimethyl-1,3-cyclohexadiene at 150℃; for 4 h; Autoclave
Alkylation of hydroquinone with tert-butanol was carried outin an autoclave equipped with a magnetic stirrer. Typically, 0.5 ghydroquinone, 1.0 g tert-butanol, and 0.20 g catalyst were addedto the autoclave, along with 2 g of xylene as a solvent. The reac-tion lasted 4 h under 150C. The products were analyzed witha gas chromatograph equipped with a SE-30 capillary column(30 m × 0.25 mm × 0.3 m) and a flame ionization detector. Thetemperature of the capillary column was set at 180C. The mainproducts were 2-tert-butyl hydroquinone (2-TBHQ), 2,5-di-tert-butyl hydroquinone (2,5-TBHQ), 2,5-di-tert-butyl benzoquinone(2,5-DTBBQ) and tert-butyl phenol ether (TBPE).
Reference：
[1] Journal of Molecular Catalysis A: Chemical, 2013, vol. 380, p. 84 - 89
[2] Chinese Journal of Catalysis, 2014, vol. 35, # 11, p. 1874 - 1882
21
[ 123-31-9 ]
[ 75-65-0 ]
[ 6669-13-2 ]
[ 2460-77-7 ]
[ 88-58-4 ]
[ 1948-33-0 ]
Yield
Reaction Conditions
Operation in experiment
48.8%
With porous pillared-zirconium phosphate functionalized with methyl group In 5,5-dimethyl-1,3-cyclohexadiene at 150℃; for 4 h; Autoclave
Alkylation of hydroquinone with tert-butanol was carried outin an autoclave equipped with a magnetic stirrer. Typically, 0.5 ghydroquinone, 1.0 g tert-butanol, and 0.20 g catalyst were addedto the autoclave, along with 2 g of xylene as a solvent. The reac-tion lasted 4 h under 150C. The products were analyzed witha gas chromatograph equipped with a SE-30 capillary column(30 m × 0.25 mm × 0.3 m) and a flame ionization detector. Thetemperature of the capillary column was set at 180C. The mainproducts were 2-tert-butyl hydroquinone (2-TBHQ), 2,5-di-tert-butyl hydroquinone (2,5-TBHQ), 2,5-di-tert-butyl benzoquinone(2,5-DTBBQ) and tert-butyl phenol ether (TBPE).
Reference：
[1] Journal of Molecular Catalysis A: Chemical, 2013, vol. 380, p. 84 - 89
[2] Chinese Journal of Catalysis, 2014, vol. 35, # 11, p. 1874 - 1882
22
[ 1634-04-4 ]
[ 123-31-9 ]
[ 2444-28-2 ]
[ 88-58-4 ]
[ 2460-87-9 ]
[ 1948-33-0 ]
Reference：
[1] Applied Catalysis A: General, 2013, vol. 450, p. 34 - 41
23
[ 123-31-9 ]
[ 115-11-7 ]
[ 88-58-4 ]
[ 2467-52-9 ]
[ 1948-33-0 ]
Reference：
[1] Australian Journal of Chemistry, 1997, vol. 50, # 5, p. 515 - 516
24
[ 1948-33-0 ]
[ 88-32-4 ]
Reference：
[1] Journal of Medicinal Chemistry, 1979, vol. 22, # 5, p. 569 - 571
[2] Patent: US4469897, 1984, A,
[3] Angewandte Chemie - International Edition, 2014, vol. 53, # 41, p. 11056 - 11059[4] Angew. Chem., 2015, vol. 126, # 41, p. 11236 - 11239,4
With phosphoric acid; In water; at 59 - 81℃; for 2h;
1) 3 parts by weight of phosphoric acid, 0.1 part by weight of water was poured into a stirring cylinder, and 6 parts by weight of hydroquinone was added to the stirring cylinder to carry out stirring;2) After stirring, the mixed solution was placed in a reaction kettle and heated to 59 C, and then the reaction vessel was charged with t-butanolCopies;3) heating to 81 C, the insulation for 2 hours to react;4) the reaction product by centrifugal separation, washing, dehydration after TBHQ crude;5) 1 part by weight of acid and 95 parts by weight of water were mixed and then heated. After heating to 81 C, 6.5 parts by weight of TBHQ was added and heated to 95 C with stirring.6) The solution of step 5) was centrifuged for the first time, the DTBHQ insoluble in water in the crude TBHQ was separated, and then the solution was cooled. When the solution was cooled to 45C or lower, the second centrifugation was carried out, and the obtained TBHQ crystal washing, dehydration, drying, that was TBHQ boutique.Wherein the drying in step 6) is carried out by pouring the wet TBHQ boutique into a vibrating screen sieve, laying the sieved TBHQ boutique on a drying tray, having a thickness of 5 cm and drying for 8 hours.The TBHQ was obtained, where the weight percentage of TBHQ was 99.9% and the weight percentage of DTBHQ was 0.1%.
44.8%
With phosphoric acid; In water; at 80℃; for 4h;Large scale;
S1. Add 0.6kg of purified water to the reaction vessel, 4.0kg of phosphoric acid (85%), Then add 1.2kg of starting material 1,4-hydroquinone, When stirring is started, when the temperature is raised to 80 , add 0.8kg of tert-butanol, Incubate the reaction for 2h to obtain the crude reaction product; S2. Immediately add 22.8kg of purified water to the crude reaction product, warm to 90 C, keep warm for 2h, filter the system while hot, and filter at 85 C S3. The filtrate is cooled and crystallized, the crystallizing temperature is 25 , and the crystallizing time is 8h; S4. The precipitated solid is filtered and dried to obtain the product 2-tert-butylhydroquinone, and the yield and purity of the product are determined. Specifically, the purity of the product is determined by high performance liquid chromatography, and the measurement results are shown in Table 9.
With phosphoric acid; In water; at 69 - 83℃; for 3h;
1) 5 parts by weight of phosphoric acid and 0.5 part by weight of water were poured into a stirring tank, and then 4 parts by weight of hydroquinone was added to the stirring cylinder,(2) After stirring, the mixed solution is put into a reaction kettle and heated to 69 DEG C, and 10 parts by weight of t-butanol are added to the reaction kettle;In this case,(3) heating to 83 C while maintaining heating for 3 hours to carry out the reaction;(4) the reaction product by centrifugal separation, washing, dehydration obtained after TBHQ crude.TBHQ crude synthetic process, can be directly prepared TBHQ crude, without further processing, process is simple, accurate measurement data, easy to implement.
at 20℃; for 3h;
. Preparation of tert-butyl hydroquinone:Add the mixture prepared in step 2 to 300 ml of deionized water.Add hydroquinone and tert-butanol,Alkylation at 20 C,The reaction time is 3 hours.Producing tert-butyl hydroquinone;Among them, hydroquinone: mixture:The equivalent ratio of tert-butanol is 1:0.3-0.8:1.2.
Under stirring, urea (6 g, 100 mmol) and tert-butyl alcohol (7.4 g, 99 mmol) were added to 75% H2SO4 (100 mL) slowly at room temperature. After 2h30? toluhydroquinone (10 g, 80 mmol) was added to the reaction mixture at 0-5 C. After stirring at room temperature for 3h, the reaction mixture was quenched and extracted with ethyl acetate (3×100 mL). The organic layer was washed successively with saturated aqueous sodium bicarbonate (3x100 mL), brine (100 mL) and water (100 mL), then dried over anhydrous sodium sulfate. After removing the drying agent by filtration, the solvent was evaporated in vacuo to give the product as a light brown solid (10.6 g, yield 74%). 1H NMR (400 MHz, CDCl3) delta 6.72 (s, 1H), 6.46 (s, 1H), 4.52 (bs, 1H), 2.16 (s, 3H), 1.38 (s, 9H). 13C NMR (100 MHz, CDCl3) delta 147.7, 147.0, 134.9, 121.7, 118.9, 114.1, 34.2, 29.6, 15.1. MP: 109-111C IR (CDCl3, 0.05M, cm-1) nu 3603, 3448, 2961, 2871, 1652, 1515, 1452, 1409, 1176, 1134.
Stage #1: tert-butylhydroquinone With potassium-t-butoxide In tetrahydrofuran for 0.5h; Cooling with ice; Inert atmosphere;
Stage #2: iodomethane In tetrahydrofuran Cooling with ice;
2 Example 2. New Preparation Method for 2-tert-butyl-4-methoxyphenol (2-BHA)
2-tert-butyl hydroquinone (0.78 g, 5 mmol) was dissolved in anhydrous tetrahydrofuran (10 mL) in an ice-salt bath, and then added into potassium tert-butoxide (0.51 g, 4.5 mmol) in tetrahydrofuran (10 mL) slowly under the protection of N2 gas. After completing the addition, the resulting mixture was stirred for 30 minutes, followed by adding dropwise iodomethane (0.57 g, 4.5 mmol), and then stirred overnight in an ice-salt bath. The reaction was quenched by adding saturated ammonium chloride solution. The reaction product was extracted with ethyl acetate (30 mL×3), washed with saturated brine three times, and recrystallized with petroleum ether (5 mL) to obtain a product with a yield of 85%.
85%
Stage #1: tert-butylhydroquinone With potassium-t-butoxide In tetrahydrofuran for 0.5h; Cooling with ice; Inert atmosphere;
Stage #2: iodomethane In tetrahydrofuran Cooling with ice;
2 Example 2. New Preparation Method for 2-tert-butyl-4-methoxyphenol (2-BHA)
2-tert-butyl hydroquinone (0.78 g, 5 mmol) was dissolved in anhydrous tetrahydrofuran (10 mL) in an ice-salt bath, and then added into potassium tert-butoxide (0.51 g, 4.5 mmol) in tetrahydrofuran (10 mL) slowly under the protection of N2 gas. After completing the addition, the resulting mixture was stirred for 30 minutes, followed by adding dropwise iodomethane (0.57 g, 4.5 mmol), and then stirred overnight in an ice-salt bath. The reaction was quenched by adding saturated ammonium chloride solution. The reaction product was extracted with ethyl acetate (30 mL×3), washed with saturated brine three times, and recrystallized with petroleum ether (5 mL) to obtain a product with a yield of 85%.
With (iPr4PCP)IrH4; hydrogen; In toluene; at 60℃; under 760.051 Torr; for 2h;
General procedure: To a Teflon stoppered tube shaped glass ampoule ?4.8mL in volume, 0.166mmol of the desired para-benzoquinone, a stir bar, and 0.25mL toluene containing 0.5mg iPrPCPIrH4 are added. Then the solution is freeze-pump-thaw degassed twice, and 1atm H2 applied. The sealed vessel is heated at a given temperature in an aluminum heat block with stirring for a prescribed period of time. When the reaction is ceased, volatiles are removed until only several muL toluene remain, and then the ampoule is quickly sealed. After this, 0.5mL THF-d8 is added and the solution transferred to an NMR tube for analysis.
97.3%
With palladium on activated charcoal; hydrogen; In dichloromethane; at 60℃; under 22502.3 Torr; for 2h;
1) Combine 390g of 2-tert-butylphenol,2,8-Dimethyl-4-diphenylphosphino-1,5-naphthyridine copper (I) complex 7g and acetonitrile 8L were added to the autoclave in turn, heated to 70 oC with stirring, and filled with oxygen to 1.0MPa Stir for 1 hour;2) After the reaction is completed, the solvent is distilled off, and the remaining solid is washed with the solvent and then stripped to obtain 360 g of 2-tert-butyl p-benzoquinone (yield 83.4%);3) Add 2-tert-butyl-p-benzoquinone obtained in step 1), 6g of platinum carbon catalyst and 6L of dichloromethane to the high-pressure reaction kettle in turn, and after filling, fill with hydrogen to 3.0 MPa, heat and stir to 60 oC React for 2 hours;4) After distilling off the solvent at the end of the reaction, 353.5 g of tert-butyl hydroquinone was obtained by rectification (yield 97.3%).
With [(4,5-dihydro-4,4-dimethyl-2-phenyloxazole)Ru(CH3CN)4]PF6; dihydrogen peroxide; In tetrahydrofuran; water; at 0 - 20℃; for 0.0833333h;
General procedure: To a solution of dihydroxy arene (0.34 mmol) and 2a (1.98 mg,0.0034 mmol) in THF (1.0 mL) was added H2O2 (30% aq, 50.0 mL,0.44 mmol) at 0 C. After 5 min the starting material had completelyoxidized to the quinone product. The quinone product wasthen extracted by ether or dichloromethane, dried over anhydrous Na2SO4, and concentrated under reduced pressure to afford thedesired product. Pleasingly, the resulted quinone products werepure enough and there is no necessity for column chromatographyin most of the cases.
86%
With silica gel supported cerium(IV) ammonium nitrate-NaBrO3; In dichloromethane; water; at 40℃; for 2h;
General procedure: A solution of CAN (0.056 g, 0.102 mmoles) and sodium bromate (0.780 g, 5.17 mmoles) in H2O (3 mL) was added slowly to vigorously stirred anhydrous silica gel (5 g) that was contained in a 100 mLround-bottom flask containing a magnetic stirring bar and fitted with a rubber septum. After complete addition of the aqueous solution, stirring was continued until a free-flowing powder was obtained.CH2Cl2 (25 mL) was then added to the flask and a solution of hydroquinone 1A (220.23 mg, 2.0 mmol), in CH2Cl2 (5 mL) was added slowly to the stirred heterogeneous mixture. A condenser was attached to the flask and the reaction was heated to reflux. Disappearance of 1A was monitored by thin-layer chromatography (EtOAc-hexane, 1:4; panisaldehyde/sulfuric acid as staining agent). Upon complete disappearance of 1A (ca. 2 h), the reaction mixture was filtered through a sintered glass funnel, the solid residue was washed with additional CH2Cl2 (3 × 10 mL), and the washings were added to the filtrate. Removal of solvent from the organic solution under vacuum gave an orange solid. Radial chromatography of the crude product (EtOAc-hexane,1:9) gave 1,4-benzoquinone 2A (89 mg, 82%) as an orange solid.
In acetone;
EXAMPLE 15 The reaction was made under the same conditions as those in the procedure of EXAMPLE 1 except that the aromatic diol compound was 83.1g (0.5 mole) of t-butylhydroquinone and 250 ml of acetone was used as the solvent. No unreacted t-butylhydroquinone was detected and the yield of t-butyl-p-benzoquinone was 99.9%.
With potassium carbonate; In chloroform; water; at 20℃; under 760.051 Torr; for 4h;Catalytic behavior;
5.4. Typical procedure for hydroquinone oxidationtert-Butyl-1,4-hydroquinone (8, 0.23 mmol), K2CO3 (0.23 mmol),and the aqueous catalyst (0.13 mol %) were stirred in a biphasicCHCl3/H2O 3:1 (2 mL) mixture at room temperature. The reactionmixture was stirred until complete consumption of the startingmaterial (monitored by TLC). After completion of the reaction, thecatalyst was removed by filtration and the organic solvent wasextracted with CH2Cl2, dried on Na2SO4, filtered, and evaporatedunder vacuum. Pure quinone 9 was obtained without any furtherpurification.1H NMR (400 MHz, CDCl3): d 1.28 (s, 9H), 6.59 (s, 1H), 6.67 (m,2H) ppm.
30.4 mg
With polymer-incarcerated aluminum and gold nanocluster catalyst with actual loading of gold/aluminum of 0.297/2.466 mmol g-1; air; In chloroform-d1; water; at 30℃; for 24h;
2-(tert-Butyl)benzene-1,4-diol (33.2 mg, 0.2 mmol), PIAL Au3 (0.297 mmol/g, 1 mol%), chloroform-d (1.12 mL), and water (0.08 mL) werecombined in a round-bottomed flask. After the mixture was stirred for 24 h under airat 30 C, the reaction mixture was filtered and dried over Na2SO4. The solvent wasremoved in vacuo to afford 2-(tert-butyl)cyclohexa-2,5-diene-1,4-dione (30.4 mg,92% yield) without further purification. The purity of product was determined byNMR spectrum. 1H NMR (CDCl3, 400 MHz) delta = 1.26 (s, 9H), 6.57 (s, 1H), 6.65 (s,1H); 13C NMR (CDCl3, 100 MHz) delta = 29.1, 35.2, 131.5, 134.9, 138.7, 156.0, 187.4,188.4.
With 1H-imidazole; dmap; In dichloromethane; at 0 - 4℃; for 18h;Inert atmosphere;
A flame-dried 500 mL round-bottomed flask equipped with a stir bar was charged with 2-<strong>[1948-33-0]tert-butylhydroquinone</strong> (6) (20.0 g, 120 mmol), imidazole(16.4 g, 241 mmol), and DMAP (2.20 g, 18 mmol), respectively. The flask was flushed with N2,and distilled CH2Cl2 (200 mL) was added. The solution was cooled to 0 C in an ice bath, and pivaloyl chloride (17.8 mL, 145 mmol) was added via syringe. The positive pressure N2 line was then replaced with an N2 balloon, and the reaction was stirred at 4 C for 18 h. After 18 h, the reaction was warmed to room temperature and diluted with CH2Cl2 (600 mL). The solution was washed with 1 M HCl (2 x 500 mL), saturated NaHCO3 (1 x 500 mL), and brine, respectively. After drying over Na2SO4, solvent was removed under reduced pressure to yield 29.3 g (97%) of a light-gray solid, pure by 1H NMR. This material was used in the next step without further purification.
EXAMPLE 6 Phenol, 2-(1,1-dimethylethyl)-4-[(3,7-dimethyloctyl)oxy]-, (MDL 104,191) STR13 Stir a mixture of 2-t-butyl-hydroquinone (8.3 g, 0.05 mol) and dimethylacetamide (100 mL) under positive argon in an ice bath. Add sodium hydride (2.0 g, 60% dispersion in oil, 0.05 mol) and stir the reaction mixture for 1 hr (and/or evolution of H2 stopped). Add <strong>[59965-20-7]1-bromo-3,7-dimethyloctane</strong> (11.1 g, 0.05 mol) and allow the mixture to warm to room temperature. Allow the precipitate which forms to dissolve (~3 hrs.). Stir the dark brown mixture at room temperature overnight, dilute with H2 O and diethyl ether. Extract the ether layer, wash and evaporate to dryness to provide a brown semi-solid product (16.4 g). Distill the brown semi-solid product in a kugelrohr. Starting material (3.4 g, to 120 C., 0.1 mm Hg) may be collected prior to collection of other fractions. A product fraction collected (~130-155 C., 0.1 mm Hg) gives an oil (~6.5 g). Collect another product fraction (150-185 C., 0.1 mm Hg) to give an oil (~4.1 g). Combine the two product fractions (~6.5 g+~4.1 g) with an additional product fraction from a previous run of the same example (~4.6 g) and evaporate to dryness to give an oil (~15.5 g). Purify the oil by silica gel chromatography eluding sequentially with hexane (500 mL), CCl4:hexane (500 mL, 1:1) and CCl4 to a straw colored oil (9.2 g).
In ISOPROPYLAMIDE;
EXAMPLE 6 Phenol, 2-(1,1-dimethylethyl)-4-[(3,7-dimethyloctyl)oxy]-, (MDL 104,191) Stir a mixture of 2-t-butyl-hydroquinone (8.3 g, 0.05 mol) and dimethylacetamide (100 mL) under positive argon in an ice bath. Add sodium hydride (2.0 g, 60% dispersion in oil, 0.05 mol) and stir the reaction mixture for 1 hr (and/or evolution of H2 stopped). Add <strong>[59965-20-7]1-bromo-3,7-dimethyloctane</strong> (11.1 g, 0.05 mol) and allow the mixture to warm to room temperature. Allow the precipitate which forms to dissolve (~3 hrs.). Stir the dark brown mixture at room temperature overnight, dilute with H2O and diethyl ether. Extract the ether layer, wash and evaporate to dryness to provide a brown semi-solid product (16.4 g). Distill the brown semi-solid product in a kugelrohr. Starting material (3.4 g, to 120C, 0.1 mm Hg) may be collected prior to collection of other fractions. A product fraction collected (~130-155C, 0.1 mm Hg) gives an oil (~6.5 g). Collect another product fraction (150-185C, 0.1 mm Hg) to give an oil (~4.1 g). Combine the two product fractions (~6.5 g + ~4.1 g) with an additional product fraction from a previous run of the same example (~4.6 g) and evaporate to dryness to give an oil (~15.5 g). Purify the oil by silica gel chromatography eluding sequentially with hexane (500 mL), CCl4:hexane (500 mL, 1:1) and CCl4 to a straw colored oil (9.2 g).
With hydrogenchloride; In hexane; chloroform; water;
EXAMPLE 1 2-t-butyl hydroquinone (Ic) of 3.0 g (18 mmol) are dissolved in 50 ml of chloroform, and wherein 50 ml of 10% hypochloride solution (6.0 g NaOCl, 80 mmol) containing 200 mg (0.59 mmol) of tetra-n-butyl ammonium are added. The solution of hypochloride had been so prepared as to be at pH 8 by using conc. hydrochloric acid, before use. The mixture reacted is stirred severely for five minutes at room temperature, then, the water and the organic layers of the reacted mixture are separated from each other, and the organic layer is washed with 180 ml of cold water. Thereafter, the organic layer having been washed is dried up by magnesium sulfate anhydrous, and chloroform is removed therefrom at reduced pressure and at 30 C., and the residue is crystallized from 10 ml of hexane. Then, 2-t-butyl benzoquinone (III c) of 2.60 g (15.9 mmol) are obtained. Yield at 88%, m.p. at 54-55 C. [Value in the literature: at 52-55 C. from I. Buben and J. Pospisil, Collect Czech., Chem. Commun., 34, 1991 (1969).]
With 3-(4-sulfobutylamino)propylsilanized MCM-41; In nitrobenzene; at 150℃; for 0.133333h;Microwave irradiation; Green chemistry;Catalytic behavior;
Friedel-Crafts reactions were performed with microwave irradiation assistance by modifying the synthesis condition [30]. Prior to reaction, hydroquinone (Merck, 2.0 mmol), methyl tert-butyl ether (MTBE, Merck, 2.0 mmol) and freshly activated SO3H-MCM-41 catalyst (0.1 g, 100 C, 3 h) were loaded into a reactor. The reaction was realized in an Anton Paar Synthos 3000 microwave oven under magnetic stirring and 300 W microwave irradiation, while the reaction temperature was monitored by an infrared pyrometer. The samples were withdrawn after the reaction and the liquid phase was separated and analyzed using a gas chromatograph (Hewlett-Packard 5880) equipped with a Carbowax Equity 1 non-polar capillary column. The identity of the product was confirmed by GC-MS (Perkin-Elmer GC-IR 2000 system).
With laccase; benzotriazol-1-ol; In aq. phosphate buffer; at 5 - 20℃; for 12h;pH 7.0;Green chemistry; Enzymatic reaction;
General procedure: Catechol or hydroquinone (1 mM) and Meldrum?s acid(2 mM) were taken in 15 mL of phosphate/citrate bufferpH 7 solution. Then, purified laccase (400 U) and0.01 mmol of HBT were added to the resultant solutionand stirred well at 5 8C with a magnetic stirrer. Thetemperature of the reaction mixture was graduallyincreased up to room temperature. The progress of thereaction was monitored by TLC examination at intervals of30 min. Upon completion of the reaction, approximatelyafter 12 h, the reaction mixture was extracted withethylacetate (3 15, i.e. three-time extraction with 15 mLof ethylacetate). The organic layer was dried overanhydrous Na2SO4. The aqueous phase was further usedfor another run without any pre-treatment. The productwas purified by column chromatography using aluminiumoxide as a stationary phase and hexane:ethyl acetate(80:20) as a mobile phase. Products were unambiguouslycharacterized by spectral data2.4.11 Compound 9f: 7-(tert-butyl)-5,8-dihydroxy-2,2-dimethyl-1,3,9-trioxa-fluoren-4-one Mp > 300 C; IR (KBr) 3423, 3422,1706, 1615, 1618 cm-1; 1HNMR, delta (400 MHz, DMSO-d6) 1.28 (s, 9H), 1.64 (s, 3H), 1.66 (s, 3H), 6.50 (s, 1H), 8.02 (s, br), 8.16 (s, br); 13CNMR, delta (100 MHz, DMSO-d6) 21.90, 22.84, 23.17, 31.65, 85.18, 102.17, 108.00, 110.79, 124.40, 143.25, 144.78, 163.25, 170.16. Anal. calcd. for C15H16O6; C, 62.74; H, 5.92; found C, 62.80, H, 5.98; ESI-MS: 307.28 (M + 1).
With porous pillared-zirconium phosphate functionalized with methyl group; In 5,5-dimethyl-1,3-cyclohexadiene; at 150℃; for 4.0h;Autoclave;
Alkylation of hydroquinone with tert-butanol was carried outin an autoclave equipped with a magnetic stirrer. Typically, 0.5 ghydroquinone, 1.0 g tert-butanol, and 0.20 g catalyst were addedto the autoclave, along with 2 g of xylene as a solvent. The reac-tion lasted 4 h under 150C. The products were analyzed witha gas chromatograph equipped with a SE-30 capillary column(30 m × 0.25 mm × 0.3 m) and a flame ionization detector. Thetemperature of the capillary column was set at 180C. The mainproducts were 2-tert-butyl hydroquinone (2-TBHQ), 2,5-di-tert-butyl hydroquinone (2,5-TBHQ), 2,5-di-tert-butyl benzoquinone(2,5-DTBBQ) and tert-butyl phenol ether (TBPE).
With perfluorosulfonicacid?functionalized carbon nanotubes (PFSA?CNT?0.5); In 5,5-dimethyl-1,3-cyclohexadiene; for 4.0h;Autoclave;Catalytic behavior;
Alkylation of hydroquinone was carried out in a stainlesssteel autoclave with a PTFE liner using magnetic stirring. Typically,0.5 g hydroquinone, 1.0 g tert?butanol, and 0.2 g catalystwere added in the autoclave accompanied with 2 g xylene assolvent. The reaction lasted 4 h. The products were analyzedwith a GC122 gas chromatograph equipped with a SE?54 capillarycolumn (30 m 0.25 mm 0.3 m) and a flame ionizationdetector
7-tert-butyl-2,5-di(methylsulfanyl)-3,4-diphenylbenzo[1,2-b:4,3-b']difuran[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
66%
With trifluoroacetic anhydride; In dichloromethane; acetonitrile; at 25℃; for 1h;
General procedure: In a reaction flask, 4-tert-butylphenol (30 mg, 0.20mmol) and 1a (51 mg, 0.24mmol) were dissolved in dichloromethane (2 mL). Trifluoroacetic anhydride (33 L, 0.24mmol) was added to the solution at 25 C. After being stirred for 30 min, the mixture was filtered through a pad of alumina and the filtrate was concentrated. Chromatographic purification on silica gel (hexane/CH2Cl2 = 5/1) yielded 5-(tert-butyl)-2-methylsulfanyl-3-phenylbenzo[b]furan (2a, 51 mg, 0.17mmol, 87%).
3-(tert-butyl)-4-hydroxyphenyl cinnamate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
85%
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine; In dichloromethane; for 6h;
General procedure: 5.1.2 3-(tert-Butyl)-4-hydroxyphenyl cinnamate (2a) Compound 2a was prepared in a similar manner to that described in the synthesis of compound 1 with the cinnamic acid instead of 2,4-dichlorobenzoic acid with a 85% yield as a white solid. ESI(+)-MS (m/z): 297.3 [M+H]+; 1H NMR (400 MHz, CDCl3): delta 7.89 (d, J = 16.0 Hz, 1H), 7.67-7.53 (m, 2H), 7.50-7.36 (m, 3H), 7.05 (d, J = 2.7 Hz, 1H), 6.89 (dd, J = 8.5, 2.7 Hz, 1H), 6.73-6.60 (m, 2H), 5.12 (s, 2H), 1.43 (s, 9H).; 5.1.1 3-(tert-Butyl)-4-hydroxyphenyl 2,4-dichlorobenzoate (1) 2,4-Dichlorobenzoic acid 6a (190 mg, 1 mmol) and 2-(tert-butyl)benzene-1,4-diol 7 (166 mg, 1 mmol) were dissolved in DCM (5 mL) with stirring. Then EDCI (210 mg, 1.1 mmol), DIEPA (400 mg, 3 mmol), and DMAP (12 mg, 0.1 mmol) were added in the system. After stirring 6 h, the mixture was diluted with DCM (15 mL), washed with water (10 mL) and brine, and dried to yield the crude product. The crude product was purified with column chromatography (petroleum ether (60-90 C)/acetone) on silica gel to afford the desired products 1 (200 mg, 63%).
3-(tert-butyl)-4-hydroxyphenyl 2-phenylacetate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
88%
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine; In dichloromethane; for 6h;
General procedure: 5.1.3 3-(tert-Butyl)-4-hydroxyphenyl 2-phenylacetate (2b) Compound 2b was prepared in a similar manner to that described in the synthesis of compound 1 with the phenylacetic acid instead of 2,4-dichlorobenzoic acid with a 88% yield as a white solid. ESI(+)-MS (m/z): 285.6 [M+H]+; 1H NMR (400 MHz, CDCl3): delta 7.44-7.27 (m, 5H), 6.92 (d, J = 2.8 Hz, 1H), 6.73 (dd, J = 8.5, 2.8 Hz, 1H), 6.60 (dd, J = 8.5, 1.3 Hz, 1H), 4.79 (s, 1H), 3.84 (s, 2H), 1.37 (s, 9H).; 5.1.1. 3-(tert-Butyl)-4-hydroxyphenyl 2,4-dichlorobenzoate (1); 2,4-Dichlorobenzoic acid 6a (190 mg, 1 mmol) and 2-(tertbutyl)benzene-1,4-diol 7 (166 mg, 1 mmol) were dissolved inDCM (5 mL) with stirring. Then EDCI (210 mg, 1.1 mmol), DIEPA(400 mg, 3 mmol), and DMAP (12 mg, 0.1 mmol) were added inthe system. After stirring 6 h, the mixture was diluted with DCM(15 mL), washed with water (10 mL) and brine, and dried to yieldthe crude product. The crude product was purified with columnchromatography (petroleum ether (60-90 C)/acetone) on silicagel to afford the desired products 1 (200 mg, 63%).
3-(tert-butyl)-4-hydroxyphenyl furan-2-carboxylate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
89%
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine; In dichloromethane; for 6h;
General procedure: 5.1.4 3-(tert-Butyl)-4-hydroxyphenyl furan-2-carboxylate (2c) Compound 2c was prepared in a similar manner to that described in the synthesis of compound 1 with the furan-2-carboxyl acid instead of 2,4-dichlorobenzoic acid with a 89% yield as a white solid. ESI(+)-MS (m/z): 261.2 [M+H]+; 1H NMR (400 MHz, CDCl3): delta 7.67 (dd, J = 1.8, 0.9 Hz, 1H), 7.36 (dd, J = 3.5, 0.9 Hz, 1H), 7.07 (d, J = 2.8 Hz, 1H), 6.92 (dd, J = 8.5, 2.8 Hz, 1H), 6.72-6.64 (m, 1H), 6.59 (dd, J = 3.5, 1.8 Hz, 1H), 4.86 (s, 1H), 1.40 (s, 9H).; 5.1.1. 3-(tert-Butyl)-4-hydroxyphenyl 2,4-dichlorobenzoate (1); 2,4-Dichlorobenzoic acid 6a (190 mg, 1 mmol) and 2-(tertbutyl)benzene-1,4-diol 7 (166 mg, 1 mmol) were dissolved inDCM (5 mL) with stirring. Then EDCI (210 mg, 1.1 mmol), DIEPA(400 mg, 3 mmol), and DMAP (12 mg, 0.1 mmol) were added inthe system. After stirring 6 h, the mixture was diluted with DCM(15 mL), washed with water (10 mL) and brine, and dried to yieldthe crude product. The crude product was purified with columnchromatography (petroleum ether (60-90 C)/acetone) on silicagel to afford the desired products 1 (200 mg, 63%).
3-(tert-butyl)-4-hydroxyphenyl 4-methylbenzoate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
94%
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine; In dichloromethane; for 6h;
General procedure: 5.1.5 3-(tert-Butyl)-4-hydroxyphenyl 4-methylbenzoate (2d) Compound 2d was prepared in a similar manner to that described in the synthesis of compound 1 with the 4-methylbenzoic acid instead of 2,4-dichlorobenzoic acid with the 94% yield as a white solid. ESI(+)-MS (m/z): 285.2 [M+H]+; 1H NMR (400 MHz, CDCl3): delta 8.11 (d, J = 8.2 Hz, 2H), 7.33 (d, J = 8.2 Hz, 2H), 7.08 (d, J = 2.8 Hz, 1H), 6.92 (dd, J = 8.5, 2.8 Hz, 1H), 6.69 (d, J = 8.5 Hz, 1H), 5.06 (s, 1H), 2.47 (s, 3H),1.43 (s, 9H).; 5.1.1. 3-(tert-Butyl)-4-hydroxyphenyl 2,4-dichlorobenzoate (1); 2,4-Dichlorobenzoic acid 6a (190 mg, 1 mmol) and 2-(tertbutyl)benzene-1,4-diol 7 (166 mg, 1 mmol) were dissolved inDCM (5 mL) with stirring. Then EDCI (210 mg, 1.1 mmol), DIEPA(400 mg, 3 mmol), and DMAP (12 mg, 0.1 mmol) were added inthe system. After stirring 6 h, the mixture was diluted with DCM(15 mL), washed with water (10 mL) and brine, and dried to yieldthe crude product. The crude product was purified with columnchromatography (petroleum ether (60-90 C)/acetone) on silicagel to afford the desired products 1 (200 mg, 63%).
3-(tert-butyl)-4-hydroxyphenyl 4-chlorobenzoate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
91%
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine; In dichloromethane; for 6h;
General procedure: 5.1.6 3-(tert-Butyl)-4-hydroxyphenyl 4-chlorobenzoate (2e) Compound 2e was prepared in a similar manner to that described in the synthesis of compound 1 with the 4-chlorobenzoic acid instead of 2,4-dichlorobenzoic acid with a 91% yield as a white solid. ESI(+)-MS (m/z): 305.1 [M+H]+; 1H NMR (400 MHz, CDCl3): delta 8.15 (d, J = 8.5 Hz, 2H), 7.51 (d, J = 8.5 Hz, 2H), 7.08 (d, J = 2.8 Hz, 1H), 6.93 (dd, J = 8.5, 2.8 Hz, 1H), 6.70 (d, J = 8.5 Hz, 1H), 4.96 (s, 1H), 1.43 (s, 9H).; 5.1.1. 3-(tert-Butyl)-4-hydroxyphenyl 2,4-dichlorobenzoate (1); 2,4-Dichlorobenzoic acid 6a (190 mg, 1 mmol) and 2-(tertbutyl)benzene-1,4-diol 7 (166 mg, 1 mmol) were dissolved inDCM (5 mL) with stirring. Then EDCI (210 mg, 1.1 mmol), DIEPA(400 mg, 3 mmol), and DMAP (12 mg, 0.1 mmol) were added inthe system. After stirring 6 h, the mixture was diluted with DCM(15 mL), washed with water (10 mL) and brine, and dried to yieldthe crude product. The crude product was purified with columnchromatography (petroleum ether (60-90 C)/acetone) on silicagel to afford the desired products 1 (200 mg, 63%).
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine; In dichloromethane; for 6h;
General procedure: 5.1.7 3-(tert-Butyl)-4-hydroxyphenyl benzoate (2f) Compound 2f was prepared in a similar manner to that described in the synthesis of compound 1 with the benzoic acid instead of 2,4-dichlorobenzoic acid with a 93% yield as a white solid. ESI(+)-MS (m/z): 271.5 [M+H]+; 1H NMR (400 MHz, CDCl3): delta 8.31-8.08 (m, 2H), 7.67-7.60 (m, 1H), 7.57-7.42 (m, 2H), 7.07 (d, J = 2.8 Hz, 1H), 6.93 (dd, J = 8.5, 2.8 Hz, 1H), 6.69 (d, J = 8.5 Hz, 1H), 4.83 (s, 1H), 1.41 (s, 9H).; 5.1.1. 3-(tert-Butyl)-4-hydroxyphenyl 2,4-dichlorobenzoate (1); 2,4-Dichlorobenzoic acid 6a (190 mg, 1 mmol) and 2-(tertbutyl)benzene-1,4-diol 7 (166 mg, 1 mmol) were dissolved inDCM (5 mL) with stirring. Then EDCI (210 mg, 1.1 mmol), DIEPA(400 mg, 3 mmol), and DMAP (12 mg, 0.1 mmol) were added inthe system. After stirring 6 h, the mixture was diluted with DCM(15 mL), washed with water (10 mL) and brine, and dried to yieldthe crude product. The crude product was purified with columnchromatography (petroleum ether (60-90 C)/acetone) on silicagel to afford the desired products 1 (200 mg, 63%).
3-(tert-butyl)-4-hydroxyphenyl 2-methylbenzoate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
83%
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine; In dichloromethane; for 6h;
General procedure: 5.1.8 3-(tert-Butyl)-4-hydroxyphenyl 2-methylbenzoate (2g) Compound 2g was prepared in a similar manner to that described in the synthesis of compound 1 with the 2-methylbenzoic acid instead of 2,4-dichlorobenzoic acid with a 83% yield as a white solid. ESI(+)-MS (m/z): 285.5 [M+H]+; 1H NMR (400 MHz, CDCl3): delta 8.20-8.13 (m, 1H), 7.49 (td, J = 7.5, 1.5 Hz, 1H), 7.26 - 7.20 (m, 2H), 7.08 (d, J = 2.8 Hz, 1H), 6.94 (dd, J = 8.5, 2.8 Hz, 1H), 6.73 (d, J = 8.5 Hz, 1H), 4.93 (s, 1H), 2.68 (s, 3H), 1.44 (s, 9H).; 5.1.1. 3-(tert-Butyl)-4-hydroxyphenyl 2,4-dichlorobenzoate (1); 2,4-Dichlorobenzoic acid 6a (190 mg, 1 mmol) and 2-(tertbutyl)benzene-1,4-diol 7 (166 mg, 1 mmol) were dissolved inDCM (5 mL) with stirring. Then EDCI (210 mg, 1.1 mmol), DIEPA(400 mg, 3 mmol), and DMAP (12 mg, 0.1 mmol) were added inthe system. After stirring 6 h, the mixture was diluted with DCM(15 mL), washed with water (10 mL) and brine, and dried to yieldthe crude product. The crude product was purified with columnchromatography (petroleum ether (60-90 C)/acetone) on silicagel to afford the desired products 1 (200 mg, 63%).
3-(tert-butyl)-4-hydroxyphenyl 2-methoxylbenzoate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
79%
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine; In dichloromethane; for 6h;
General procedure: 5.1.9 3-(tert-Butyl)-4-hydroxyphenyl 2-methoxylbenzoate (2h) Compound 2h was prepared in a similar manner to that described in the synthesis of compound 1 with the 2-methoxyl benzoic acid instead of 2,4-dichlorobenzoic acid with a 79% yield as a white solid. ESI(+)-MS (m/z): 301.3 [M+H]+; 1H NMR (400 MHz, CDCl3): delta 8.04 (dd, J = 7.9, 1.5 Hz, 1H), 7.56 (td, J = 8.2, 1.5 Hz, 1H), 7.09 (d, J = 2.8 Hz, 1H), 7.09-7.03 (m, 2H), 6.94 (dd, J = 8.5, 2.8 Hz, 1H), 6.69 (d, J = 8.5 Hz, 1H), 5.05 (s, 1H), 3.87 (s, 3H), 1.43 (s, 9H).; 5.1.1. 3-(tert-Butyl)-4-hydroxyphenyl 2,4-dichlorobenzoate (1); 2,4-Dichlorobenzoic acid 6a (190 mg, 1 mmol) and 2-(tertbutyl)benzene-1,4-diol 7 (166 mg, 1 mmol) were dissolved inDCM (5 mL) with stirring. Then EDCI (210 mg, 1.1 mmol), DIEPA(400 mg, 3 mmol), and DMAP (12 mg, 0.1 mmol) were added inthe system. After stirring 6 h, the mixture was diluted with DCM(15 mL), washed with water (10 mL) and brine, and dried to yieldthe crude product. The crude product was purified with columnchromatography (petroleum ether (60-90 C)/acetone) on silicagel to afford the desired products 1 (200 mg, 63%).
3-(tert-butyl)-4-hydroxyphenyl 4-nitrobenzoate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
83%
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine; In dichloromethane; for 6h;
General procedure: 5.1.10 3-(tert-Butyl)-4-hydroxyphenyl 4-nitrobenzoate (2i) Compound 2i was prepared in a similar manner to that described in the synthesis of compound 1 with the 4-nitrobenzoic acid instead of 2,4-dichlorobenzoic acid with a 83% yield as a white solid. ESI(+)-MS (m/z): 316.7 [M+H]+; 1H NMR (400 MHz, CDCl3): delta 8.41-8.33 (m, 4H), 7.09 (d, J = 2.8 Hz, 1H), 6.94 (dd, J = 8.5, 2.8 Hz, 1H), 6.71 (d, J = 8.5 Hz, 1H), 4.90 (s, 1H), 1.42 (s, 9H).; 5.1.1. 3-(tert-Butyl)-4-hydroxyphenyl 2,4-dichlorobenzoate (1); 2,4-Dichlorobenzoic acid 6a (190 mg, 1 mmol) and 2-(tertbutyl)benzene-1,4-diol 7 (166 mg, 1 mmol) were dissolved inDCM (5 mL) with stirring. Then EDCI (210 mg, 1.1 mmol), DIEPA(400 mg, 3 mmol), and DMAP (12 mg, 0.1 mmol) were added inthe system. After stirring 6 h, the mixture was diluted with DCM(15 mL), washed with water (10 mL) and brine, and dried to yieldthe crude product. The crude product was purified with columnchromatography (petroleum ether (60-90 C)/acetone) on silicagel to afford the desired products 1 (200 mg, 63%).
3-(tert-butyl)-4-hydroxyphenyl 2,6-dichloro-4-nitrobenzoate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
57%
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine In dichloromethane for 6h;
5.1.12 5.1.12 3-(tert-Butyl)-4-hydroxyphenyl 2,6-dichloro-4-nitrobenzoate (2k)
General procedure: 5.1.12 3-(tert-Butyl)-4-hydroxyphenyl 2,6-dichloro-4-nitrobenzoate (2k) Compound 2k was prepared in a similar manner to that described in the synthesis of compound 1 with the 2,6-dichloro-4-nitrobenzoic acid instead of 2,4-dichlorobenzoic acid with a 57% yield as a white solid. ESI(+)-MS (m/z): 383.2 [M+H]+; 1H NMR (400 MHz, CDCl3): δ 8.29 (s, 2H), 7.14 (d, J = 2.8 Hz, 1H), 7.04 (dd, J = 8.5, 2.8 Hz, 1H), 6.75 (d, J = 8.5 Hz, 1H), 5.06 (s, 1H), 1.44 (s, 9H).; 5.1.1. 3-(tert-Butyl)-4-hydroxyphenyl 2,4-dichlorobenzoate (1); 2,4-Dichlorobenzoic acid 6a (190 mg, 1 mmol) and 2-(tertbutyl)benzene-1,4-diol 7 (166 mg, 1 mmol) were dissolved inDCM (5 mL) with stirring. Then EDCI (210 mg, 1.1 mmol), DIEPA(400 mg, 3 mmol), and DMAP (12 mg, 0.1 mmol) were added inthe system. After stirring 6 h, the mixture was diluted with DCM(15 mL), washed with water (10 mL) and brine, and dried to yieldthe crude product. The crude product was purified with columnchromatography (petroleum ether (60-90 C)/acetone) on silicagel to afford the desired products 1 (200 mg, 63%).
6-(tert-butyl)-2,3-dihydrobenzo[b][1,4]dithiine-5,8-dione[ No CAS ]
1,2,3-trithiolane[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
68%
With laccase from Trametes Villosa; oxygen; In methanol; at 22℃; for 16h;pH 5.0;Green chemistry; Enzymatic reaction;
General procedure: The hydroquinone 2 (0.50 mmol) was added to a 50 mL round bottom flask equipped with a stir bar followed by 15 mL of solvent and the mixture was stirred. Once the solid had dissolved, 1,2-ethanedithiol 1 (2.50 mmol) was introduced, followed by 50 U of laccase. The reaction mixture was stirred at room temperature (22 C) for 16 h whilst O2 was bubbled through. The reaction progress was monitored by TLC using silica gel coated on aluminum sheets as the stationary phase, 1:1 EtOAc/hexane (v:v) mixture as the mobile phase, and iodine vapor as the staining agent. Once the reaction was complete, the reaction mixture was extracted with EtOAc (3× 20 mL), dried over MgSO4, and the solvent removed via rotary evaporation. The crude extract was purified via column chromatography using silica gel as the stationary phase and 1:1 EtOAc/hexane (v:v) mixture as the mobile phase to obtain the desired products. The products were characterized using HRMS, 1H NMR, 13C NMR, and FTIR.
With potassium carbonate; In dimethyl sulfoxide; at 25℃; for 1h;Green chemistry;
General procedure: Diacetylated compound 3a-10a (1 mmol) and its corresponding dihydroxyl compound 3-10 (1 mmol) were dissolved in DMSO, respectively, and then K2CO3 (1 mmol) was added. The reaction mixture was stirred at 25 C. After the reaction was complete, the mixture was poured into water and extracted by ethyl acetate (325 mL). The organic phase was washed successively by water (325 mL) and brine (225 mL), and then dried over anhydrous Na2SO4, filtered. The filtrate was evaporated in vacuum and the residue was purified by column chromatography to give pure target compounds.
Reaction1 Hydroquinone 110kg 116kg acetic acid tert-ester and sulfuric acid concentration of 50% sulfuric acid 294kg added to the reaction kettle was warmed up to 85 C to a reaction for 8 hours to complete the reaction, cooling to 65 C rear centrifugal filtration, filtrate recycling sulfuric acid, the resulting added 1 times warm water washing, the crude product of tert-butyl hydroquinone, wherein the tert-butyl hydroquinone content is 70%.
With dmap; dicyclohexyl-carbodiimide; In chloroform; at 20℃; for 3h;
1.0g of tert-butyl hydroquinone, 6.0 g of compound (e), 0.2 g of 4 - dimethylaminopyridine and 121 g of chloroform were of mixed. To the resulting mixture, a solution obtained by 4.5 g of N, N'-dicyclohexylcarbodiimide dissolved in 24 g of chloroform was added dropwise at room temperature to react for 3 hours. And then 2 N hydrochloric acid, 60 g was added to the reaction solution, the resulting mixture was filtered. After washing the filtrate with 2 N hydrochloric acid, 60 g, and concentrated to obtain a concentrated solution of about 40 g. 0.3 g of activated carbon was added to the concentrate and was filtered through celite. The solvent from the resulting filtrate was evaporated. To the resulting concentrated residue was obtained solid was added to methanol. The obtained solid was washed with methanol to obtain a white solid of compound (1-a3) 4.1 g. Yield: 71% (tert- butyl hydroxy basis).
With Na+-K+/MgO-CaO bimetallic basic catalyst at 170℃; for 4h; Autoclave;
1-17 Example 17
General procedure: In a high pressure reactor equipped with a condenser, the raw material TBHQ 332g was added to the reaction vessel and passed through a high purity N2 test.The airtightness of the autoclave was released. After the pressure was released, 3.3 g of a bimetallic basic catalyst and 90 g of dimethyl carbonate were added to the reaction vessel at a reaction temperature of 180 ° C. The maximum pressure during the reaction was maintained at 1.2 MPa, and the reaction time was 7.0 h. . After the reaction is completed, the temperature of the reaction vessel is lowered to room temperature by condensed water, and a small amount of the reaction liquid is taken in the sample tube, and after gas chromatography. In the case where the BHA synthesis process is identical to that of Example 1, the amount of catalyst is changed to 6.6 g, and the reaction time is changed. It was 4 h, and the reaction temperature was 170 ° C to obtain a reaction liquid of BHA. Quantitative analysis by gas chromatography showed that the conversion of TBHQ was 34%, the selectivity to 3-BHA was 98%, and the yield of BHA was 33.32%.
Chemistry
Pharmaceutical Intermediates
Inhibitors/Agonists
Material Science
For Research Only
110K+ Compounds
Competitive Price
1-2 Day Shipping
