1,2-Dibromoethane → Ethyl 2-[5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphth-2-yl]benzoate

HRID 1636530Notes

Reaction equation

HRID 1636530 reaction equation
[Mg].Br[C:3]1[CH:12]=[CH:11][C:10]2[C:9]([CH3:14])([CH3:13])[CH2:8][CH2:7][C:6]([CH3:16])([CH3:15])[C:5]=2[CH:4]=1.BrCCBr.[CH2:21]([O:23][C:24](=[O:32])[C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][C:26]=1Br)[CH3:22]>C1COCC1.C(OCC)C.C(OC(=O)C)C.[Cl-].[Cl-].[Zn+2]>[CH3:13][C:9]1([CH3:14])[CH2:8][CH2:7][C:6]([CH3:16])([CH3:15])[C:5]2[CH:4]=[C:3]([C:30]3[CH:29]=[CH:28][CH:27]=[CH:26][C:25]=3[C:24]([O:23][CH2:21][CH3:22])=[O:32])[CH:12]=[CH:11][C:10]1=2

Participants

8

Reactant 4

HCID 78391,2-DibromoethaneHCID 80186Ethyl 2-bromobenzoateHCID 2266856-Bromo-1,1,4,4-tetramethyl-1,2,3,4-tetrahydronaphthalene2×HCID 5462224Magnesium

Product 1

HCID 18357939Ethyl 2-[5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphth-2-yl]benzoate

Reagents, catalysts & solvents 3

HCID 3007855ZincchlorideCatalystHCID 8028TetrahydrofuranSolvent4×HCID 21584169Diethylether ethylacetateSolvent

Procedure

To magnesium (180 mgs, 7.5 mmols) in THF (3 ml) was added a solution of 2-bromo-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene (200 mgs) in THF (5 ml) followed by 1,2-dibromoethane (94 mgs, 0.5 mmol). The mixture was stirred for 15 mins, then another portion of 2-bromo-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene (1.14 g, 5 mmols) in THF (10 ml) was added. The mixture was stirred for 15 mins at room temperature, and refluxed for 1 h. ZnCl2 (680 mgs, 5 mmols) was added, stirred for 40 mins, and to the white precipitate. ethyl-2-bromobenzoate (1.09 g) in THF (5 ml) was added, immediately followed by addition of Ni(PPh2CH2CH2)Cl2 (26 mgs, 0.05 mmols). The mixture was stirred at room temperature for 16h. The reaction mixture was diluted with diethyl ether : ethylacetate (1:1, a total of 180 ml), the organic phase was washed with water (10 ml), brine (10 ml) NaHCO3 (10 ml) and brine (10 ml), dried (MgSO4) and the solvent was removed under reduced pressure. Silicagel chromatography (5% ethyl acetate in hexane) followed by HPLC purification of the crude material gave the title compound as a colorless oil. PMR (CDCl3): δ 0.89 (3H, t, j=7.1 Hz), 1.29 (6H, s), 1.31 (6H, s), 4.04 (2H, q, j=7.1 Hz), 7.09 (1H, dd, j=2.0, 8.1 Hz), 7.22 (1H, d, j=2.0 Hz), 7.33 (1H, d, j=8.1 Hz), 7.40 (2H, d, j=6.9 Hz), 7.46-7.55 (1H, m), 7.76 (1H, d, j=7.1 Hz).

Workup

  1. stirringThe mixture was stirred for 15 mins at room temperature
  2. temperaturerefluxed for 1 h
  3. stirringstirred for 40 mins
  4. stirringThe mixture was stirred at room temperature for 16h
  5. washa total of 180 ml), the organic phase was washed with water (10 ml), brine (10 ml) NaHCO3 (10 ml) and brine (10 ml)
  6. dry with materialdried (MgSO4)
  7. customthe solvent was removed under reduced pressure
  8. customSilicagel chromatography (5% ethyl acetate in hexane) followed by HPLC purification of the crude material

Sources & evidence

ORD record
ord-a0c6d588c218495a9259c359e88b1be1
Source dataset
uspto-grants-2000_03
Patent number
US06034242

Reaction notes

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