1,4-Dibromobutane → HCID 53822570, compound

HRID 259940Notes

Reaction equation

HRID 259940 reaction equation
[Br-].[Li+].[Br:3][CH2:4][CH2:5][CH2:6][CH2:7]Br.[CH3:9][O:10][C:11]1[CH:16]=[C:15]([O:17][CH3:18])[CH:14]=[CH:13][C:12]=1[Mg]Br>C1COCC1.[Cu]Br>[Br:3][CH2:4][CH2:5][CH2:6][CH2:7][C:14]1[CH:13]=[CH:12][C:11]([O:10][CH3:9])=[CH:16][C:15]=1[O:17][CH3:18]

Participants

6

Reactant 3

HCID 80561,4-DibromobutaneHCID 82050Lithium BromideHCID 178491918HCID 178491918, compound

Product 1

HCID 53822570HCID 53822570, compoundYield 73.2%

Reagents, catalysts & solvents 2

HCID 24593copper(I) bromideCatalystHCID 8028TetrahydrofuranSolvent3×

Procedure

Commercially available copper(I)bromide (7.17 g, 50 mmol) and anhydrous lithium bromide (8.68 g, 100 mmol) were added to anhydrous THF (100 mL). Vigorous shaking gave a dark greenish solution. 11.5 mL (5.75 mmol) of this solution was added to a mixture of 1,4-dibromobutane (74.8 g, 346 mmol) in THF (90 mL). The mixture was warmed to 40 C., after which a solution of 2,4-dimethoxyphenylmagnesium bromide (115 mmol) in THF (100 mL), prepared by standard methods, was added over 45 min. The temperature was never more than 50 C. After the addition, the mixture was stirred for an additional 1 h at 50 C. The reaction mixture was allowed to reach 30 C. after which it was poured into ice water (200 mL). Effective stirring for 10 min gave a deep blue color. The mixture was extracted with diethyl ether (2×250 mL), dried (MgSO4) and evaporated. The excess of 1,4-dibromobutane was distilled off, and the residue was filtered through a short column of silica gel (hexane-EtOAC, 95:5). Evaporation gave the title compound as a colorless liquid (23.0 g): 1H NMR (CDCl3 -d) 7.00 (d, J=8.0 Hz, 1H), 6.44-6.39 (m, 2H), 3.79 (s, 6H), 3.42 (t, J=6.9 Hz, 2H), 2.56 (t, J=7.5 Hz, 2H), 1.90-1.83 (m, 2H), 1.73-1.62 (m, 2H); 13C NMR (CDCl3 - d) 159.13, 158.24, 129.90, 122.56, 103.74, 98.44, 55.30, 55.22, 33.87, 32.47, 28.56 (two overlapping carbon); MS (EI, 70 eV): m/z (rel. int.) 274/272 (M+, 100/96), 151 (54), 121 (43), 91 (14).

Workup

  1. customgave a dark greenish solution
  2. temperatureThe mixture was warmed to 40 C
  3. additionwas added over 45 min
  4. additionAfter the addition
  5. stirringthe mixture was stirred for an additional 1 h at 50 C
  6. stirringEffective stirring for 10 min
  7. customgave a deep blue color
  8. extractionThe mixture was extracted with diethyl ether (2×250 mL)
  9. dry with materialdried (MgSO4)
  10. customevaporated
  11. distillationThe excess of 1,4-dibromobutane was distilled off
  12. filtrationthe residue was filtered through a short column of silica gel (hexane-EtOAC, 95:5)
  13. customEvaporation

Sources & evidence

ORD record
ord-70621daf8b4d4dd0b58c9213e43d1723
Source dataset
uspto-grants-1996_06
Patent number
US05523475

Reaction notes

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