Hydrochloric Acid → 2,1-Benzoxaborole, 1,3-dihydro-1-hydroxy-5-methoxy-

HRID 916867Notes

Reaction equation

HRID 916867 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([O:8][CH3:9])=[CH:4][C:3]=1[CH2:10][O:11]C(OCC)C.C([Li])CCC.C[O:23][B:24](OC)OC.Cl>C1COCC1>[CH3:9][O:8][C:5]1[CH:6]=[CH:7][C:2]2[B:24]([OH:23])[O:11][CH2:10][C:3]=2[CH:4]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 8470Trimethyl borateHCID 589615361-Bromo-2-[(1-ethoxyethoxy)methyl]-4-methoxybenzeneHCID 178418339Butyllithium

Product 1

HCID 118461172,1-Benzoxaborole, 1,3-dihydro-1-hydroxy-5-methoxy-Yield 40.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

Dissolve 1-bromo-2-(1-ethoxy-ethoxymethyl)-4-methoxy-benzene (3.0 g, 10.3 mmol)in THF (100 mL) and cool to −78° C. Add 2.5M butyllithium in hexanes (4.6 mL, 11.4 mmol), dropwise and stir for 15 min. Add trimethylborate (2.1 g, 20.6 mmol) to the reaction mixture and warm to room temperature. Add 1N HCl (100 mL) and stir at room temperature for 2 hours. Extract three times with methylene chloride, dry the combined organic layers with sodium sulfate, filter and concentrate in vacuo to yield a crude product. Triturate with methylene chloride/hexanes to yield 680 mg (40%) of the title compound. 1H NMR (CDCl3) δ 7.65 (d, J=8.2 Hz, 1H), 6.93 (dd, J=8.2, 2.1 Hz, 1H), 6.85 (d, J=1.4 Hz, 1H), 5.06 (s, 2H), 3.86 (s, 3H).

Workup

  1. stirringstir at room temperature for 2 hours
  2. extractionExtract three times with methylene chloride
  3. dry with materialdry the combined organic layers with sodium sulfate
  4. filtrationfilter
  5. concentrationconcentrate in vacuo
  6. customto yield a crude product
  7. customTriturate with methylene chloride/hexanes

Sources & evidence

ORD record
ord-24342a5381ba4db3952a37ec27bde60c
Source dataset
uspto-grants-2007_09
Patent number
US07271264B2

Reaction notes

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