1,2-Dibromoethane → 4,4,5,5-Tetramethyl-2-(2-methylnaphthalen-1-yl)-1,3,2-dioxaborolane

HRID 1944805Notes

Reaction equation

HRID 1944805 reaction equation
BrCCBr.[Mg].Br[C:7]1[C:16]2[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=2)[CH:10]=[CH:9][C:8]=1[CH3:17].C(O[B:22]1[O:26][C:25]([CH3:28])([CH3:27])[C:24]([CH3:30])([CH3:29])[O:23]1)(C)C>C1COCC1.O>[CH3:29][C:24]1([CH3:30])[C:25]([CH3:28])([CH3:27])[O:26][B:22]([C:7]2[C:16]3[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=3)[CH:10]=[CH:9][C:8]=2[CH3:17])[O:23]1

Participants

7

Reactant 4

HCID 78391,2-DibromoethaneHCID 757541-Bromo-2-methylnaphthaleneHCID 50177412-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneHCID 5462224Magnesium

Product 1

HCID 222401864,4,5,5-Tetramethyl-2-(2-methylnaphthalen-1-yl)-1,3,2-dioxaborolane

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

1,2-Dibromoethane (˜0.3 ml) was added to 6.10 g (250 mmol) magnesium turnings in 1000 cm3 of THF. This mixture was stirred for 10 min, and then 55.3 g (250 mmol) of 1-bromo-2-methylnaphthalene was added for 1 h by vigorous stirring at room temperature for 3.5 h. Further on, 46.5 g (250 mmol) of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane was added in one portion. The resulting mixture was stirred for 15 minutes and then was poured into 1000 cm3 of cold water. The product was extracted with 3×300 ml of ethyl acetate. The organic layer was separated, washed by water, brine, then dried over MgSO4, and, finally, evaporated to dryness. The resulting white solid was washed by 2×75 ml of pentane and dried in vacuum. Yield 47.3 g (70%). Anal. calc. for C17H21BO2: C, 76.14; H, 7.89. Found: C, 76.31; H, 8.02. 1H NMR (CDCl3): 8.12 (m, 1H, 8-H), 7.77 (m, 1H, 5-H), 7.75 (d, J=8.4 Hz, 1H, 4-H), 7.44 (m, 1H, 7-H), 7.38 (m, 1H, 6-H), 7.28 (d, J=8.4 Hz, 1H, 3-H), 2.63 (s, 3H, 2-Me), 1.48 (s, 12H, CMe2CMe2).

Workup

  1. stirringby vigorous stirring at room temperature for 3.5 h
  2. stirringThe resulting mixture was stirred for 15 minutes
  3. extractionThe product was extracted with 3×300 ml of ethyl acetate
  4. customThe organic layer was separated
  5. washwashed by water, brine
  6. dry with materialdried over MgSO4
  7. customfinally, evaporated to dryness
  8. washThe resulting white solid was washed by 2×75 ml of pentane
  9. customdried in vacuum

Sources & evidence

ORD record
ord-8627294d01804cb1bd7916bbd58899c0
Source dataset
uspto-grants-2013_03
Patent number
US08394902B2

Reaction notes

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