Tetrahydrofuran → HCID 57912410, compound

HRID 884729Notes

Reaction equation

HRID 884729 reaction equation
Br[CH:2]1[CH2:7][O:6][CH2:5][CH2:4][O:3]1.[C:8]([O:11][C:12]1[CH:17]=[CH:16][C:15](B2OC(C)(C)C(C)(C)O2)=[CH:14][CH:13]=1)(=[O:10])[CH3:9].C(=O)(O)[O-].[Na+].[CH2:32]1[CH2:36]O[CH2:34][CH2:33]1>O>[C:8]([O:11][C:12]1[CH:17]=[CH:16][C:15]([C:2]2[O:3][C:4]3[CH:36]=[CH:32][CH:33]=[CH:34][C:5]=3[O:6][CH:7]=2)=[CH:14][CH:13]=1)(=[O:10])[CH3:9]

Participants

6

Reactant 4

HCID 8028TetrahydrofuranHCID 516892Sodium BicarbonateHCID 27740044-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl acetateHCID 219826212-Bromo-1,4-dioxane

Product 1

HCID 57912410HCID 57912410, compoundYield 62%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
110 °C

Procedure

To a solution of 1,4-benzodioxane (5 g, 36.72 mmol) in CCl4 (200 mL), NBS (14.38 g, 80.79 mmol) and AIBN (500 mg) were added under N2. The mixture was heated at reflux for 12 h. The reaction mixture was cooled to rt. The solution was evaporated to give the crude product, which was purified by chromatography on neutral Al2O3 using 10% EtOAc in hexane to give the di-bromo compound (9.34 g, 86%). To a stirred solution of 2,3-dibromo-2,3-dihydro-1,4-benzodioxine (9.84 g, 33.45 mmol) in Et2O (150 mL), was added potassium t-butoxide (4.5 g, 40.14 mmol) under N2. The mixture was stirred for 3 h at rt. The solid was filtered off and the solution was concentrated to give the crude product, which purified by chromatography on neutral Al2O3 using 10% EtOAc in hexane to give 2-bromodioxane (6.8 g, 95%). To a mixture of 2-bromodioxane (1.0 g, 4.69 mmol), 4-(4,4,5,5-tetramethyl-1,3-dioxaborolan-2-yl)phenyl acetate (1.23 g, 4.69 mmol), sodium bicarbonate (1.18 g, 14.07 mmol), THF (50 mL) and water (7 mL) was added tetrakis-triphenyl phosphine palladium (271 mg, 0.23 mmol) under N2. The reaction mixture was heated to 110° C. for 5 h and then cooled to rt. Water was added and the mixture was extracted with EtOAc. The organic layer was separated, washed with water, brine, dried and concentrated to give crude product, which was purified by column chromatography, using 20% EtOAc in hexane to give 775 mg of 4-(benzo[b][1,4]dioxin-2-yl)phenyl acetate (62%). MS (ES) m/z: 269.92 (M+1), 268.91 (M); Mp. 123-125° C.

Workup

  1. temperaturecooled to rt
  2. extractionthe mixture was extracted with EtOAc
  3. customThe organic layer was separated
  4. washwashed with water, brine
  5. customdried
  6. concentrationconcentrated
  7. customto give crude product, which
  8. customwas purified by column chromatography

Sources & evidence

ORD record
ord-383ad17c207c48818d0a21660c08c36a
Source dataset
uspto-grants-2012_08
Patent number
US08242130B2

Reaction notes

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