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

HRID 629849

Reaction equation

HRID 629849 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 (0.25 mol) of magnesium turnings in 1000 cm3 of THF. This mixture was stirred for 10 min, and then 55.3 g (0.25 mol) of 1-bromo-2-methylnaphtalene was added by vigorous stirring for 3.5 h at room temperature. 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 min and then 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, dried over MgSO4, and, finally, evaporated to dryness. The formed white solid was washed by 2×75 ml of pentane and then dried in vacuum. Yield 47.3 g (70%). Anal. calc. for C17H21BO2: C, 76.14; H, 7.89. Found: C, 76.21; H, 7.96. 1H NMR (CDCl3): δ 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 for 3.5 h at room temperature
  2. stirringThe resulting mixture was stirred for 15 min
  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 formed white solid was washed by 2×75 ml of pentane
  9. customdried in vacuum

Sources & evidence

ORD record
ord-be2ffcaaf82e4d69820bfa1894295393
Source dataset
uspto-grants-2016_04
Patent number
US09315526B2

Linked notes

Loading…