Methanol → tert-butyl N-[(2S)-1-oxo-3-phenylpropan-2-yl]carbamate

HRID 745463Notes

Reaction equation

HRID 745463 reaction equation
C[O:2][C:3](=O)[C@H:4]([CH2:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)[NH:5][C:6]([O:8][C:9]([CH3:12])([CH3:11])[CH3:10])=[O:7].[H-].C([Al+]CC(C)C)C(C)C.CO.[C@H](O)(C([O-])=O)[C@@H](O)C([O-])=O.[Na+].[K+]>C1(C)C=CC=CC=1.C(OCC)C>[C:9]([O:8][C:6]([NH:5][C@H:4]([CH:3]=[O:2])[CH2:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)=[O:7])([CH3:11])([CH3:12])[CH3:10]

Participants

7

Reactant 4

HCID 887MethanolHCID 9357Potassium Sodium TartrateHCID 9882138Boc-L-phenylalanine methyl esterHCID 21225700Diisobutylaluminumhydride

Product 1

HCID 6998013tert-butyl N-[(2S)-1-oxo-3-phenylpropan-2-yl]carbamate

Reagents, catalysts & solvents 2

HCID 1140TolueneSolvent2×HCID 3283Diethyl EtherSolvent

Conditions

Temperature
-78 °C

Procedure

N-t-Butoxycarbonyl-L-phenylalanine methyl ester (250 g., 0.90 mol) was dried by addition and removal at reduced pressure of 1.0 1. dry toluene, and dissolved in dry toluene (3 1.) in a 12 1. flask equipped with septum, nitrogen inlet, overhead stirrer, and thermometer. The solution was cooled to -78° C. and a solution of diisobutylaluminum hydride was added via cannula over a period of 0.5 hour so that the temperature was maintained below -70° C. After being stirred an additional 15 minutes, absolute methanol (250 ml.) was added (dropwise at first until vigorous effervescence subsided) at -78° C. followed 20 minutes later by 3.0 1. of 50% Rochelle salt solution (also slowly at first). Diethyl ether (2 1.) was added to the mixture, and the temperature was raised to 20° C. On standing the layers separated, and the aqueous was extracted with ether (2×1.5 1.). The organic phase was washed with brine, dried sodium sulfate and concentrated to give crude N-t-butoxycarbonyl-L-phenylalaninal which was used immediately without purification.

Workup

  1. customflask equipped with septum, nitrogen inlet, overhead stirrer
  2. temperaturewas maintained below -70° C
  3. customat -78° C.
  4. waitfollowed 20 minutes later by 3.0 1
  5. temperaturethe temperature was raised to 20° C
  6. customseparated
  7. extractionthe aqueous was extracted with ether (2×1.5 1.)
  8. washThe organic phase was washed with brine, dried sodium sulfate
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-5ebf606c620d426baf4fc7ceabd4b494
Source dataset
uspto-grants-1986_07
Patent number
US04599198

Reaction notes

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