Ethyl Acetate → 2-Bromo-3-nitrophenol

HRID 1872875Notes

Reaction equation

HRID 1872875 reaction equation
B(Br)(Br)Br.[Br:5][C:6]1C=C[C:9](OC)=[CH:8][C:7]=1[N+:14]([O-:16])=[O:15].CCO[C:20]([CH3:22])=[O:21]>C(Cl)Cl>[Br:5][C:6]1[C:7]([N+:14]([O-:16])=[O:15])=[CH:8][CH:9]=[CH:22][C:20]=1[OH:21]

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 25134Boron tribromideHCID 792884-Bromo-3-nitroanisole

Product 1

HCID 81672542-Bromo-3-nitrophenolYield 79%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

BBr3 (1 M in CH2Cl2, 77 mL, 77 mmol) was added dropwise, over 1 h, to a stirred solution of 4-bromo-3-nitroanisole (5.0 g, 22 mmol) in 30 mL CH2Cl2 at -70° C. under nitrogen. The resulting deep burgundy-colored reaction was stirred overnight (23 h) and then poured onto 300 g crushed ice. EtOAc (250 mL) was added and the organic fraction washed with brine (250 mL), dried (MgSO4) and concentrated in vacuo to 5.06 g of a yellow-brown solid. Purification by column chromatography (EtOAc/hexane, gradient elution 5:95 to 15:85) afforded 3.77 g (79%) of 2-bromo-3-nitrophenol as a yellow solid: TLC (EtOAc/hesane 20:80) Rf =0.12; HPLC (Tr =12.2); 1H-NMR (CDCl3) δ 5.57 (s, 1H, --OH), δ 6.95 (dd, J=8 Hz, J=3 Hz, 1H), δ 7.36 (d, J=3 Hz, 1H), δ 7.58 (d, J=8 Hz, 1H); MS m/z (relative intensity) 218 (MH+, 100), 220 (MH+ +2.56).

Workup

  1. customThe resulting deep burgundy-colored reaction
  2. additionpoured onto 300 g
  3. customcrushed ice
  4. washthe organic fraction washed with brine (250 mL)
  5. dry with materialdried (MgSO4)
  6. concentrationconcentrated in vacuo to 5.06 g of a yellow-brown solid
  7. customPurification
  8. washby column chromatography (EtOAc/hexane, gradient elution 5:95 to 15:85)

Sources & evidence

ORD record
ord-f2e4b3ce7a024385881873d594757e07
Source dataset
uspto-grants-2000_08
Patent number
US06110961

Reaction notes

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