1,3-Cyclohexanedione → 2-Bromocyclohexane-1,3-dione

HRID 2102778Notes

Reaction equation

HRID 2102778 reaction equation
[C:1]1(=[O:8])[CH2:6][CH2:5][CH2:4][C:3](=[O:7])[CH2:2]1.[Br:9]Br>C(Cl)Cl>[Br:9][CH:2]1[C:3](=[O:7])[CH2:4][CH2:5][CH2:6][C:1]1=[O:8]

Participants

4

Reactant 2

HCID 104341,3-CyclohexanedioneHCID 24408Bromine

Product 1

HCID 27704762-Bromocyclohexane-1,3-dioneYield 63.7%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of 1,3-cyclohexanedione (50 g, 0.45 mol) in CH2Cl2 (111 mL) was stirred at 5° C. Bromine (18 mL, 56.3 g, 0.35 mol) in CH2Cl2 (17 mL) was added dropwise over a period of 5-10 min. The reaction mixture was stirred at room temperature for 1 h. The brown precipitate that formed was collected by filtration, washed with CH2Cl2/toluene (100 mL), and air dried, before being crystallized from H2O to afford the title compound as pale yellow crystals (42.6 g, 50%): mp 167-168° C. Anal. RP-HPLC: tR 7.9 min (0-60% MeCN, purity 100%). 1H-NMR (DMSO-d6): δ 2.49 (t, 4H, J 6.1, 2×CH2), 1.85 (qu, 2H, J 6.1, CH2). MS (ESI−): m/z 190.90/188.90 (M-H)+.

Workup

  1. customThe brown precipitate that formed
  2. filtrationwas collected by filtration
  3. washwashed with CH2Cl2/toluene (100 mL), and air
  4. customdried
  5. custombefore being crystallized from H2O

Sources & evidence

ORD record
ord-929753303796449bad52c9cb757d4cff
Source dataset
uspto-grants-2009_08
Patent number
US07576091B2

Reaction notes

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