Overview[1][2]
Dibromoquinone is an organic intermediate that can be prepared from 1,4-dihydroxybenzene in two steps.
Preparation[1]
Step 1
2,5-Dibromobenzene-1,4-diol: To a suspension of 1,4-dihydroxybenzene (101) (0.2 mol, 22 g) in glacial acetic acid (200 mL) with stirring A solution of bromine (0.4 mol, 64 g, 20.5 mL) in glacial acetic acid (20 mL) was added. The temperature rose slightly after the reaction. A colorless precipitate formed in 10 minutes. Then, the solution was stirred for 1 hour. The resulting solid was aspirated and washed with a small amount of glacial acetic acid. The mother liquor was concentrated to give additional product (0.16 mol, 43.9 g, 82%, melting point 185-187°C, 188-189°C). Hydroquinone was used in the next reaction without further purification.
Step 2
2,5-Dibromo-[1,4]benzoquinone: In the catalytic reaction, CH3 of 2,5-dibromobenzene-1,4-diol (2.67g, 10.0mmol) CN (50mL) and water (10mL) were mixed with CAN (2mol%) and TBHP/CH2Cl2 (3.6mmol/mL, 2.5eq., 7.0 mL) treatment. Add the TBHP solution dropwise to the solution using a Perfusor over 8 hours. After reaction (12 hours), the solvent was removed in vacuo and the residue was dissolved in dichloromethane. Extract the organic phase with dilute hydrochloric acid (2mol/L, 30mL), water (30mL) and saturated NaHCO3. Wash with saturated aqueous NaCl solution (30 mL) and dry over MgSO4. After removal of the solvent in vacuo, dibromoquinone was obtained as a yellow solid (2.36 g, 90%, melting point 179-180°C).
Apply[2]
CN201710069649.2 discloses a modified attapulgite for immobilizing polycyclic aromatic hydrocarbon-degrading bacteria. Attapulgite is prepared into substance B by modifying a mixture prepared by sodium bicarbonate, cinnamic aldehyde, 3-oxetanone, dibromoquinone, methyl salicylate, anisole and myrcene; substance B Substance D was prepared after modification with a mixture of isobutyl mercaptan, hexyl sulfide, o-chlorocinnamic acid and 3-methylthiophene; Substance D was modified with N-acetyl-DL-phenylalanine, 5-hydroxychloroquine Substance F was prepared by modifying a mixture prepared from hydroxypropyl cellulose, galacturonic acid and bromine. The substance is modified attapulgite used to immobilize PAH-degrading bacteria.
Main reference materials
[1] Frank M. HauserRichard P. Rhee, 4H-Anthra[1,2-b]pyran antibiotics. Total synthesis of the methyl ether of kidamycinone, J. Am. Chem. Soc.1979,101,6, 1628-1629
[2] CN201710069649.2 Modified attapulgite for immobilizing polycyclic aromatic hydrocarbon-degrading bacteria and its preparation method
