Imidazole → 5-(2-Bromoethyl)-2-benzofuran-1(3H)-one

HRID 1519486Notes

Reaction equation

HRID 1519486 reaction equation
O[CH2:2][CH2:3][C:4]1[CH:13]=[CH:12][C:7]2[C:8](=[O:11])[O:9][CH2:10][C:6]=2[CH:5]=1.C(Br)(Br)(Br)[Br:15].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.N1C=CN=C1>C(Cl)Cl>[Br:15][CH2:2][CH2:3][C:4]1[CH:13]=[CH:12][C:7]2[C:8](=[O:11])[O:9][CH2:10][C:6]=2[CH:5]=1

Participants

6

Reactant 4

HCID 795ImidazoleHCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 666439615-(2-hydroxyethyl)-2-benzofuran-1(3H)-one

Product 1

HCID 675131635-(2-Bromoethyl)-2-benzofuran-1(3H)-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of 5-(2-hydroxyethyl)-2-benzofuran-1(3H)-one (1.2 g, 6.8 mmol) in DCM at 0° C. was added carbon tetrabromide (2.3 g, 6.8 mmol), triphenylphosphine (1.8 g, 6.8 mmol), and imidazole (0.46 g, 6.8 mmol). The mixture was allowed to stir at 0° C. for 5 minutes, and then allowed to warm to RT and stir for 1.5 hours. The crude was concentrated and purified by silica gel chromatography (43% EtOAc with Hexanes). About 1.3 grams of 5-(2-Bromoethyl)-2-benzofuran-1(3H)-one was collected as a white solid. LC-MS (IE, m/z): 241/243 (M+1)+.

Workup

  1. temperatureto warm to RT
  2. stirringstir for 1.5 hours
  3. concentrationThe crude was concentrated
  4. custompurified by silica gel chromatography (43% EtOAc with Hexanes)
  5. customAbout 1.3 grams of 5-(2-Bromoethyl)-2-benzofuran-1(3H)-one was collected as a white solid

Sources & evidence

ORD record
ord-ec36ad3927944cd5a788805312af40dd
Source dataset
uspto-grants-2015_07
Patent number
US09073882B2

Reaction notes

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