Boron tribromide → 7-Hydroxy-2,3-bis(4-hydroxyphenyl)quinoxaline-6-carboxylic acid

HRID 2205126Notes

Reaction equation

HRID 2205126 reaction equation
B(Br)(Br)Br.[OH:5][C:6]1[CH:15]=[C:14]2[C:9]([N:10]=[C:11]([C:24]3[CH:29]=[CH:28][C:27]([O:30]C)=[CH:26][CH:25]=3)[C:12]([C:16]3[CH:21]=[CH:20][C:19]([O:22]C)=[CH:18][CH:17]=3)=[N:13]2)=[CH:8][C:7]=1[C:32]([OH:34])=[O:33]>C(Cl)Cl>[OH:5][C:6]1[CH:15]=[C:14]2[C:9]([N:10]=[C:11]([C:24]3[CH:29]=[CH:28][C:27]([OH:30])=[CH:26][CH:25]=3)[C:12]([C:16]3[CH:21]=[CH:20][C:19]([OH:22])=[CH:18][CH:17]=3)=[N:13]2)=[CH:8][C:7]=1[C:32]([OH:34])=[O:33]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 1364080817-Hydroxy-2,3-bis(4-methoxyphenyl)quinoxaline-6-carboxylic acid

Product 1

HCID 1364080827-Hydroxy-2,3-bis(4-hydroxyphenyl)quinoxaline-6-carboxylic acidYield 64.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

BBr3 (1.26 g, 5.02 mmol, 10.00 equiv) was added dropwise with stifling at 0° C. to a solution of 7-hydroxy-2,3-bis(4-methoxyphenyl)quinoxaline-6-carboxylic acid (200 mg, 0.50 mmol, 1.00 equiv) in DCM (20 mL) in a 50-mL round-bottom flask. The resulting solution was allowed to react, with stirring, overnight at room temperature. The reaction was quenched by the addition of 10 mL of 1N (aq) NaOH. The pH of the solution was adjusted to 3-4 with HCl (1M). The solution was extracted with 2×100 mL of CH2Cl2: MeOH (10:1), and the organic layers combined and concentrated under vacuum, yielding 120 mg (64%) of 7-hydroxy-2,3-bis(4-hydroxyphenyl)quinoxaline-6-carboxylic acid as a red solid.

Workup

  1. customto react
  2. customThe reaction was quenched by the addition of 10 mL of 1N (aq) NaOH
  3. extractionThe solution was extracted with 2×100 mL of CH2Cl2: MeOH (10:1)
  4. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-10c5511f190d4862a7615e4db8a31cce
Source dataset
uspto-grants-2016_06
Patent number
US09370522B2

Reaction notes

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