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

HRID 1837474Notes

Reaction equation

HRID 1837474 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 in vacuo 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 in vacuo at room temperature

Sources & evidence

ORD record
ord-2b1fe5b4dc964e399f59066bede4a5b4
Source dataset
uspto-grants-2004_08
Patent number
US06784180B2

Reaction notes

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