HCID 12128809, compound → 2,5-Dibromo-3,4-dihydro-1(2H)-naphthalenone

HRID 2308205Notes

Reaction equation

HRID 2308205 reaction equation
[Br:1][C:2]1(Br)[CH2:11][CH2:10][C:9]2[C:4](=[CH:5][CH:6]=[CH:7][C:8]=2[Br:12])[C:3]1=[O:13]>O>[Br:1][CH:2]1[CH2:11][CH2:10][C:9]2[C:4](=[CH:5][CH:6]=[CH:7][C:8]=2[Br:12])[C:3]1=[O:13]

Participants

3

Reactant 1

HCID 12128809HCID 12128809, compound

Product 1

HCID 121288082,5-Dibromo-3,4-dihydro-1(2H)-naphthalenoneYield 98.5%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A clear yellow solution of 5-bromo-3,4-dihydro-1(2H)-naphthalenone (12.09 g, 53.7 mmol) in freshly opened Et2O (220 mL) under an N2 atmosphere was chilled to −5° C. HCl was bubbled in subsurface for 1 min, causing no visible change. The dropwise addition of a solution of Br2 (8.58 g, 53.7 mmol) in CH2Cl2 (20 mL) and Et2O (2 mL) to the vigorously stirring solution of 5-bromo-3,4-dihydro-1(2H)-naphthalenone over 2 h (each drop was allowed to fully decolorize before adding the next) produced a product mixture that assayed by HPLC. Peak area showed 79.4% title compound, 9.5% unreacted 5-bromo-3,4-dihydro-1(2H)-naphthalenone, 0.6% unidentified, and 9.4% 2,2,5-tribromo-1-tetralone. The addition of H2O produced a top light brown organic phase, and a clear, colorless bottom aqueous phase which was separated. After drying with MgSO4, the organic layer was concentrated under vacuum at room temperature to give the crude intermediate title compound as a light brown oil (16.08 g, 98.5%).

Workup

  1. customproduced a top light brown organic phase
  2. customa clear, colorless bottom aqueous phase which was separated
  3. dry with materialAfter drying with MgSO4
  4. concentrationthe organic layer was concentrated under vacuum at room temperature

Sources & evidence

ORD record
ord-801edc6120d447d8b22eee3494dec036
Source dataset
uspto-grants-2004_12
Patent number
US06835733B2

Reaction notes

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