Acetic Acid → (S)-2-benzylamino-3-phenyl-1-propanol

HRID 433101Notes

Reaction equation

HRID 433101 reaction equation
[NH2:1][C@H:2]([CH2:10][OH:11])[CH2:3][C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1.C(O)(=O)C.[CH:16](=O)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1.C([BH3-])#N.[Na+]>CO>[CH2:16]([NH:1][C@H:2]([CH2:10][OH:11])[CH2:3][C:4]1[CH:5]=[CH:6][CH:7]=[CH:8][CH:9]=1)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 240BenzaldehydeHCID 447213phenylalaninol, (S)-HCID 5003444Sodium cyanoborohydride

Product 1

HCID 10514267(S)-2-benzylamino-3-phenyl-1-propanolYield 81%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent4×

Procedure

L-Phenylalaninol (89.51 g, 0.592 moles) was dissolved in 375 mL of methanol under inert atmosphere, 35.52 g (0.592 moles) of glacial acetic acid and 50 mL of methanol was added followed by a solution of 62.83 g (0.592 moles) of benzaldehyde in 100 mL of methanol. The mixture was cooled to. approximately 15° C. and a solution of 134.6 g(2.14 moles) of sodium cyanoborohydride in 700 mL of methanol was added in approximately 40 minutes, keeping the temperature between 15° C. and 25° C. The mixture was stirred at room temperature for 18 hours. The mixture was concentrated under reduced pressure and partitioned between 1 L of 2M ammonium hydroxide solution and 2 L of ether. The ether layer was washed with 1 L of 1M ammonium hydroxide solution, twice with 500 mL water, 500 mL of brine and dried over magnesium sulfate for 1 hour. The ether layer was filtered, concentrated under reduced pressure and the crude solid product was recrystallized from 110 mL of ethyl acetate and 1.3 L of hexane to give 115 g (81% yield) of N-benzyl-L-phenylalaninol as a white solid.

Workup

  1. additionwas added
  2. temperatureThe mixture was cooled to
  3. customthe temperature between 15° C. and 25° C
  4. concentrationThe mixture was concentrated under reduced pressure
  5. custompartitioned between 1 L of 2M ammonium hydroxide solution and 2 L of ether
  6. washThe ether layer was washed with 1 L of 1M ammonium hydroxide solution, twice with 500 mL water, 500 mL of brine
  7. dry with materialdried over magnesium sulfate for 1 hour
  8. filtrationThe ether layer was filtered
  9. concentrationconcentrated under reduced pressure
  10. customthe crude solid product was recrystallized from 110 mL of ethyl acetate and 1.3 L of hexane

Sources & evidence

ORD record
ord-baf88a4343654692a858ab6c821e38e9
Source dataset
uspto-grants-2003_12
Patent number
US06667307B2

Reaction notes

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