1,2-Dibromoethane → 2,3-Dihydro-2-methyl-5-trifluoromethoxybenzofuran

HRID 1017270Notes

Reaction equation

HRID 1017270 reaction equation
I[C:2]1[CH:7]=[C:6]([O:8][C:9]([F:12])([F:11])[F:10])[CH:5]=[CH:4][C:3]=1[O:13][CH:14](OS(C1C=CC(C)=CC=1)(=O)=O)[CH2:15]C.[Mg].Br[CH2:30]CBr>O1CCCC1>[CH3:30][CH:14]1[CH2:15][C:4]2[CH:5]=[C:6]([O:8][C:9]([F:10])([F:11])[F:12])[CH:7]=[CH:2][C:3]=2[O:13]1

Participants

5

Reactant 3

HCID 78391,2-DibromoethaneHCID 5462224MagnesiumHCID 18403412(2-Iodo-4-trifluoromethoxyphenyloxy)-1-p-toluenesulphonyloxypropane2×

Product 1

HCID 184034092,3-Dihydro-2-methyl-5-trifluoromethoxybenzofuranYield 36%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

10 ml solution of (2-iodo-4-trifluoromethoxyphenyloxy)-1-p-toluenesulphonyloxypropane (Description 20; 16 g, 28 mmol) in tetrahydrofuran (50 ml) was added dropwise to a stirred mixture of magnesium turnings (5 g, 208 mmol) in tetrahydrofuran (20 ml). 1,2-Dibromoethane (0.1 ml) was added. The exotermic reaction started. The mixture was warm up to reflux and the rest of (2-iodo-4-trifluoromethoxyphenyloxy)-1-p-toluenesulphonyloxypropane solution was added dropwise. The reaction mixture was heated at reflux for 24 hours, then cooled to room temperature and quenched with 2M aqueous hydrochloric acid. The mixture was extracted with a 1:1 mixture iso-hexane:diethyl ether (3×100 ml). The combined organic extracts were dried (Na2SO4) and concentrated. The residue was purified by chromatography on silica gel (iso-hexane:diethyl ether 0-15%) to give the title compound (2.8 g, 36%).

Workup

  1. customThe exotermic reaction
  2. temperatureThe mixture was warm up
  3. temperatureto reflux
  4. temperatureThe reaction mixture was heated
  5. temperatureat reflux for 24 hours
  6. customquenched with 2M aqueous hydrochloric acid
  7. extractionThe mixture was extracted with a 1:1 mixture iso-hexane
  8. dry with materialThe combined organic extracts were dried (Na2SO4)
  9. concentrationconcentrated
  10. customThe residue was purified by chromatography on silica gel (iso-hexane:diethyl ether 0-15%)

Sources & evidence

ORD record
ord-7c921886362f45579ab9d8a8b6146e7d
Source dataset
uspto-grants-2002_11
Patent number
US06479486B2

Reaction notes

Loading…