Benzyl Bromide → Methyl 2-benzyl-3-dimethylaminopropionate

HRID 621618Notes

Reaction equation

HRID 621618 reaction equation
[CH3:1][N:2]([CH3:11])P(N(C)C)(N(C)C)=O.CN([CH:15]([CH3:20])[C:16]([O:18][CH3:19])=[O:17])C.[CH2:21](Br)[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1>O1CCCC1>[CH2:21]([CH:15]([CH2:20][N:2]([CH3:11])[CH3:1])[C:16]([O:18][CH3:19])=[O:17])[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 12679HexamethylphosphoramideHCID 15594675Methyl 2-(dimethylamino)propanoate

Product 1

HCID 13653933Methyl 2-benzyl-3-dimethylaminopropionate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

The reaction mixture is stirred for 1/2 hour at the same temperature, a solution of 179 g of hexamethylphosphoramide in 200 ml of tetrahydrofuran is added and stirring is continued for 1/2 hour at -78°. At the same temperature a solution of 125 g of methyl N,N-dimethylaminopropionate in 200 ml of tetrahydrofuran is then added dropwise and stirring is continued for 20 minutes. A solution of 171 g of benzyl bromide in 300 ml of tetrahydrofuran is then added, again at -78°. The solution is stirred at this temperature for 2 hours and then quenched, first with 250 ml of saturated aqueous ammonium chloride and then 250 ml of saturated aqueous sodium chloride solution. To this is added 1500 ml of ether. The layers are separated and the aqueous layer is extracted with 4×200 ml of ether. The ether extract is dried over magnesium sulfate and evaporated to dryness. The resulting oil is redissolved in 300 ml of ether, the ether solution is washed with 100 ml of water and the aqueous layer is reextracted with 3×100 ml ether. The combined ether solutions are dried over magnesium sulfate and evaporated to dryness to yield an oil which is purified by fractional distillation to yield pure methyl 2-benzyl-3-dimethylaminopropionate, b.p. 104°/0.2-0.4 mm Hg.

Workup

  1. stirringstirring
  2. waitis continued for 1/2 hour at -78°
  3. stirringstirring
  4. waitis continued for 20 minutes
  5. stirringThe solution is stirred at this temperature for 2 hours
  6. customquenched, first with 250 ml of saturated aqueous ammonium chloride
  7. additionTo this is added 1500 ml of ether
  8. customThe layers are separated
  9. extractionthe aqueous layer is extracted with 4×200 ml of ether
  10. extractionThe ether extract
  11. dry with materialis dried over magnesium sulfate
  12. customevaporated to dryness
  13. dissolutionThe resulting oil is redissolved in 300 ml of ether
  14. washthe ether solution is washed with 100 ml of water
  15. dry with materialThe combined ether solutions are dried over magnesium sulfate
  16. customevaporated to dryness
  17. customto yield an oil which
  18. distillationis purified by fractional distillation

Sources & evidence

ORD record
ord-cafb21f8f8d94fb69489a54bb97253a5
Source dataset
uspto-grants-1989_04
Patent number
US04824868

Reaction notes

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