Ethyl 3-bromopropionate → HCID 20257135, compound

HRID 637560Notes

Reaction equation

HRID 637560 reaction equation
[NH2:1][C:2]1[C:7]([O:8][CH3:9])=[C:6]([O:10][CH3:11])[CH:5]=[CH:4][C:3]=1[C:12](=[O:14])[CH3:13].Br[CH2:16][CH2:17][C:18]([O:20][CH2:21][CH3:22])=[O:19].C([O-])(O)=O.[Na+]>C(N(CC)CC)C>[C:18]([CH2:17][CH2:16][NH:1][C:2]1[C:7]([O:8][CH3:9])=[C:6]([O:10][CH3:11])[CH:5]=[CH:4][C:3]=1[C:12](=[O:14])[CH3:13])([O:20][CH2:21][CH3:22])=[O:19]

Participants

5

Reactant 3

HCID 68320Ethyl 3-bromopropionateHCID 516892Sodium BicarbonateHCID 202571331-(2-Amino-3,4-dimethoxyphenyl)ethan-1-one

Product 1

HCID 20257135HCID 20257135, compound

Reagents, catalysts & solvents 1

HCID 8471TriethylamineSolvent

Conditions

Temperature
135 °C

Procedure

Triethylamine (19.4 g, 192 mM) was added to a mixture of 2'-amino-3',4'-dimethoxyacetophenone (25 g, 128 mM) and ethyl 3-bromopropionate (139 g, 770 mM), in a 250 mL flask (equipped with a large stirring bar, reflux condenser and nitrogen inlet). The pale solid which formed was stirred at 135° C. for 5 hours. The brown homogeneous oil which formed was then cooled to 10° C. and 200 mL of 2% NaHCO3 was added. The solution was then extracted with CHCl3 (3×100 mL), the organic layer washed with H2O (100 mL) and dried over MgSO4. Following filtration, the CHCl3 and most of the bromopropionate were removed under reduced pressure. The oily residue was charged onto a 10×75 cm, SilicAR CC-7 column (800 g, hexane packed) and eluted with 5 to 20% ethyl acetate/hexane, collecting 1 L fractions. Evaporation of fractions 7-9 gave purified 2'-(N-2-carbethoxyethylamino)-3',4'-dimethoxyacetophenone as a yellow oil (5.86 g, 15%); UV (EtOH) nm: 244 (ε29110), 284 (ε11480); MS (Probe) 295 (M+).

Workup

  1. custom(equipped with a large stirring bar, reflux condenser and nitrogen inlet)
  2. customThe pale solid which formed
  3. customThe brown homogeneous oil which formed
  4. temperaturewas then cooled to 10° C.
  5. extractionThe solution was then extracted with CHCl3 (3×100 mL)
  6. washthe organic layer washed with H2O (100 mL)
  7. dry with materialdried over MgSO4
  8. filtrationfiltration
  9. customthe CHCl3 and most of the bromopropionate were removed under reduced pressure
  10. additionThe oily residue was charged onto a 10×75 cm, SilicAR CC-7 column (800 g, hexane packed)
  11. washeluted with 5 to 20% ethyl acetate/hexane
  12. customcollecting 1 L fractions
  13. customEvaporation of fractions 7-9
  14. customgave
  15. custompurified 2'-(N-2-carbethoxyethylamino)-3',4'-dimethoxyacetophenone as a yellow oil (5.86 g, 15%)

Sources & evidence

ORD record
ord-decae6df6e3845ec9a942313150f86ba
Source dataset
uspto-grants-1985_12
Patent number
US04556739

Reaction notes

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