Boron trifluoride etherate → 4-(5-Bromo-2-chlorobenzyl)phenethyl acetate

HRID 425058Notes

Reaction equation

HRID 425058 reaction equation
[C:1]([O:4][CH2:5][CH2:6][C:7]1[CH:12]=[CH:11][C:10]([C:13](=O)[C:14]2[CH:19]=[C:18]([Br:20])[CH:17]=[CH:16][C:15]=2[Cl:21])=[CH:9][CH:8]=1)(=[O:3])[CH3:2].B(F)(F)F.C(OCC)C.C([SiH](CC)CC)C>>[C:1]([O:4][CH2:5][CH2:6][C:7]1[CH:8]=[CH:9][C:10]([CH2:13][C:14]2[CH:19]=[C:18]([Br:20])[CH:17]=[CH:16][C:15]=2[Cl:21])=[CH:11][CH:12]=1)(=[O:3])[CH3:2]

Participants

4

Reactant 3

HCID 8000Boron trifluoride etherateHCID 12052TriethylsilaneHCID 595577424-(5-Bromo-2-chlorobenzoyl)phenethyl acetate

Product 1

HCID 595577874-(5-Bromo-2-chlorobenzyl)phenethyl acetateYield 65%

Conditions

Temperature
85 °C

Procedure

A mixture of 4-(5-bromo-2-chlorobenzoyl)phenethyl acetate (intermediate BF) (1 g, 2.62 mmol), borontrifluoride diethylether (0.65 mL, 10.4 mmol) and triethylsilane (0.84 mL, 10.4 mmol) was heated at 85° C. for 2 h in a sealed tube. The reaction vessel was cooled to room temperature and ice-water (50 mL) was added. The product was extracted with ethyl acetate (2×25 mL), washed with brine (25 mL), dried (Na2SO4), filtered and evaporated. Purification on silica gel using an ISCO column with 5% ethyl acetate in hexane gave intermediate BG (620 mg, yield 65%). 1H NMR (300 MHz, CDCl3): δ 7.27-7.10 (m, 7H), 4.27 (t, J=6.9, 7.2 Hz, 2H), 4.03 (s, 2H), 2.92 (t, J=6.9, 7.2 Hz, 2H), 2.05 (s, 3H).

Workup

  1. temperatureThe reaction vessel was cooled to room temperature
  2. extractionThe product was extracted with ethyl acetate (2×25 mL)
  3. washwashed with brine (25 mL)
  4. dry with materialdried (Na2SO4)
  5. filtrationfiltered
  6. customevaporated
  7. customPurification on silica gel using an ISCO column with 5% ethyl acetate in hexane
  8. customgave intermediate BG (620 mg, yield 65%)

Sources & evidence

ORD record
ord-e81af6f413df4e4492940f5f9e244757
Source dataset
uspto-grants-2012_01
Patent number
US08106021B2

Reaction notes

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