Triethylamine → 2-(5-(1,3-Dioxolan-2-yl)-2,4-dimethoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

HRID 10663

Reaction equation

HRID 10663 reaction equation
Br[C:2]1[C:3]([O:15][CH3:16])=[CH:4][C:5]([O:13][CH3:14])=[C:6]([CH:8]2[O:12][CH2:11][CH2:10][O:9]2)[CH:7]=1.CCN(CC)CC.C1(P(C2CCCCC2)C2C=CC=CC=2C2C=CC=CC=2)CCCCC1.[CH3:49][C:50]1([CH3:57])[C:54]([CH3:56])([CH3:55])[O:53][BH:52][O:51]1.[NH4+].[Cl-]>O1CCOCC1.CC([O-])=O.CC([O-])=O.[Pd+2].O>[O:9]1[CH2:10][CH2:11][O:12][CH:8]1[C:6]1[C:5]([O:13][CH3:14])=[CH:4][C:3]([O:15][CH3:16])=[C:2]([B:52]2[O:53][C:54]([CH3:56])([CH3:55])[C:50]([CH3:57])([CH3:49])[O:51]2)[CH:7]=1

Participants

9

Reactant 5

HCID 8471TriethylamineHCID 25517Ammonium ChlorideHCID 27342162-(Dicyclohexylphosphino)biphenylHCID 27347684,4,5,5-Tetramethyl[1,3,2]dioxaborolaneHCID 161160542-(5-Bromo-2,4-dimethoxyphenyl)-1,3-dioxolane

Product 1

HCID 161156182-(5-(1,3-Dioxolan-2-yl)-2,4-dimethoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneYield 92.6%

Reagents, catalysts & solvents 3

HCID 167845palladium(II) acetateCatalystHCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Procedure

Ex-46B: 2-(5-Bromo-2,4-dimethoxy-phenyl)-[1,3]dioxolane (Ex-46A, 4.78 g, 10.5 mmol) was dissolved in dioxane (75 mL) and the solution was purged with nitrogen for 15 min. Pd(OAc)2 (188 mg, 0.84 mmol), Et3N (6.91 mL, 49.6 mmol), and 2-(dicyclohexylphosphino)biphenyl (1.16 g, 3.31 mmol) were added. 4,4,5,5-Tetramethyl-[1,3,2]dioxaborolane (3.6 mL, 24.8 mmol) was added slowly, accompanied by gas evolution and the darkening of the reaction solution. The solution was heated at reflux for 2.5 h and then cooled. Saturated, aqueous NH4Cl (60 mL) and water (20 mL) were added and the solution extracted with EtOAc (1×100 mL). The organic phase was dried over sodium sulfate, filtered, and concentrated to a dark oil. The oil was purified via silica gel chromatography (1:1 EtOAc/hexanes after a column pre-wash of 5% Et3N in 1:1 EtOAc/hexanes) to provide 3.27 g of 2-(5-[1,3]dioxolan-2-yl-2,4-dimethoxy-phenyl)-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane as a yellow solid (with some starting borolane present), 59% yield. 1H-NMR (CDCl3) δ 7.85 (s, 1H), 6.39 (s, 1H), 6.07 (s, 1H), 4.13–4.18 (m, 2H), 3.98–4.02 (m, 2H), 3.89 (s, 3H), 3.84 (s, 3H), 1.33 (s, 9H).

Workup

  1. customthe solution was purged with nitrogen for 15 min
  2. temperatureThe solution was heated
  3. temperatureat reflux for 2.5 h
  4. temperaturecooled
  5. extractionthe solution extracted with EtOAc (1×100 mL)
  6. dry with materialThe organic phase was dried over sodium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated to a dark oil
  9. customThe oil was purified via silica gel chromatography (1:1 EtOAc/hexanes after a column
  10. washpre-wash of 5% Et3N in 1:1 EtOAc/hexanes)

Sources & evidence

ORD record
ord-71cc95bcc694456f8188c5073823441d
Source dataset
uspto-grants-2006_08
Patent number
US07094801B2

Linked notes

Loading…