1,1-Dibromoethane → N-tert-butoxycarbonyl 1-(2-bromo-5-fluorobenzofur-7-yl)-2-aminopropane

HRID 1824948Notes

Reaction equation

HRID 1824948 reaction equation
[C:1]([O:5][C:6]([NH:8][CH:9]([CH3:21])[CH2:10][C:11]1[C:19]2[O:18][CH:17]=[CH:16][C:15]=2[CH:14]=[C:13]([F:20])[CH:12]=1)=[O:7])([CH3:4])([CH3:3])[CH3:2].C([Li])CCC.[Br:27]C(Br)C.C(=O)(O)[O-].[Na+]>O1CCCC1.C(OCC)C>[C:1]([O:5][C:6]([NH:8][CH:9]([CH3:21])[CH2:10][C:11]1[C:19]2[O:18][C:17]([Br:27])=[CH:16][C:15]=2[CH:14]=[C:13]([F:20])[CH:12]=1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

7

Reactant 4

HCID 112011,1-DibromoethaneHCID 516892Sodium BicarbonateHCID 22144858N-tert-butoxycarbonyl 1-(5-fluorobenzofur-7-yl)-2-aminopropaneHCID 178418339Butyllithium

Product 1

HCID 22144817N-tert-butoxycarbonyl 1-(2-bromo-5-fluorobenzofur-7-yl)-2-aminopropaneYield 89%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 0.50 gm (1.71 mMol) N-tert-butoxycarbonyl 1-(5-fluorobenzofur-7-yl)-2-aminopropane in 17 mL tetrahydrofuran at −78° C. were added 2.4 mL (3.84 mMol) n-butyllithium (1.6 M in hexane) dropwise. The resulting mixture was stirred for 1.5 hour and then 0.16 mL (1.86 mMol) dibromoethane were added. After stirring for an additional hour the reaction mixture was poured into a mixture of 25 mL saturated aqueous sodium bicarbonate and 50 mL diethyl ether. The phases were separated and the organic phase was washed with saturated aqueous sodium chloride. All aqueous phases were combined and extracted with 50 mL diethyl ether. All organic phases were combined, washed with saturated aqueous sodium chloride, dried over magnesium sulfate and concentrated under reduced pressure. The residue was subjected to silica gel chromatography, eluting with a gradient of hexane containing from 0 to 15% ethyl acetate. Fractions containing product were combined and concentrated under reduced pressure to provide 0.53 gm (89%) of the desired compound.

Workup

  1. stirringAfter stirring for an additional hour the reaction mixture
  2. customThe phases were separated
  3. washthe organic phase was washed with saturated aqueous sodium chloride
  4. extractionextracted with 50 mL diethyl ether
  5. washwashed with saturated aqueous sodium chloride
  6. dry with materialdried over magnesium sulfate
  7. concentrationconcentrated under reduced pressure
  8. washeluting with a gradient of hexane containing from 0 to 15% ethyl acetate
  9. additionFractions containing product
  10. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-624587e64cfb47c98731355ed15da20a
Source dataset
uspto-grants-2006_05
Patent number
US07045545B1

Reaction notes

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