Ethyl 3-bromopropionate → HCID 20257128, compound

HRID 637561Notes

Reaction equation

HRID 637561 reaction equation
[NH2:1][C:2]1[C:7]([O:8][CH3:9])=[CH:6][CH:5]=[C:4]([O:10][CH3:11])[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])=[CH:6][CH:5]=[C:4]([O:10][CH3:11])[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 14469018HCID 14469018, compound

Product 1

HCID 20257128HCID 20257128, compound

Reagents, catalysts & solvents 1

HCID 8471TriethylamineSolvent

Conditions

Temperature
10 °C

Procedure

Triethylamine (19.4 g, 192 mM) was added to a mixture of 2'-amino-3',6'-dimethoxyacetophenone (2.5 g, 128 mM) and ethyl 3-bromopropionate (139 g, 770 mM) in a 250 mL flask. The pale solid complex so formed was stirred at 135° for 2 hours with a large and heavy stirring bar. During this time the complex became a homogeneous brown oil. This oil was cooled to 10° C. and 200 mL of 2% NaHCO3 was added to the reaction mixture. The solution was then extracted with CHCl3 (3×100 mL) and the organic layer washed with H2O (100 mL) and then dried over MgSO4. After filtration, the CHCl3 and most of the bromopropionate were removed under reduced pressure. The oily residue was put on a 10×60 cm, SilicAR CC-7 column (500 g) and eluted with 5-20% ethyl acetate/hexane, collecting 1 L fractions. Evaporation of fractions 5 and 6 gave purified 2'-(N-2-carbethoxyethylamino)-3',6'-dimethoxyacetophenone (9.97 g, 26%); IR (neat) μ: 3.3, 5.78, 5.8, 6.25.

Workup

  1. customThe pale solid complex so formed
  2. extractionThe solution was then extracted with CHCl3 (3×100 mL)
  3. washthe organic layer washed with H2O (100 mL)
  4. dry with materialdried over MgSO4
  5. filtrationAfter filtration
  6. customthe CHCl3 and most of the bromopropionate were removed under reduced pressure
  7. washeluted with 5-20% ethyl acetate/hexane
  8. customcollecting 1 L fractions
  9. customEvaporation of fractions 5 and 6
  10. customgave
  11. custompurified 2'-(N-2-carbethoxyethylamino)-3',6'-dimethoxyacetophenone (9.97 g, 26%)

Sources & evidence

ORD record
ord-7684338a8eb7457284ddf5071ec074ea
Source dataset
uspto-grants-1985_12
Patent number
US04556739

Reaction notes

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