preparation and application of dibromoquinone_kain industrial additive

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, ch_{3 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