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

HRID 2370662Notes

Reaction equation

HRID 2370662 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. Thereafter, 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. customevaporated to dryness
  8. washThe resulting white solid was washed by 2×75 ml of pentane
  9. customdried in vacuum

Sources & evidence

ORD record
ord-2b8a06243586490284147bb317d3ec24
Source dataset
uspto-grants-2014_04
Patent number
US08710163B2

Reaction notes

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