Triethylamine → benzyl [(1S)-1-formyl-2-methylpropyl]carbamate

HRID 363738Notes

Reaction equation

HRID 363738 reaction equation
[CH2:1]([O:8][C:9]([NH:11][C@H:12]([CH2:16][OH:17])[CH:13]([CH3:15])[CH3:14])=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(N(CC)CC)C>CS(C)=O>[CH2:1]([O:8][C:9]([NH:11][C@H:12]([CH:16]=[O:17])[CH:13]([CH3:15])[CH3:14])=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 8471TriethylamineHCID 10900657(S)-N-CBZ-valinol

Product 1

HCID 11009915benzyl [(1S)-1-formyl-2-methylpropyl]carbamateYield 85%

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent2×

Procedure

To a stirred solution of N-benzyloxycarbonyl-L-valinol (8.80 g, 0.037 mol) and triethylamine (30.00 g, 41.3 mL, 0.30 mol) in 100 mL dimethylsulfoxide under a nitrogen atmosphere was added a solution of sulfur trioxide pyridine complex (20.62 g, 0.130 mol) in dimethylsulfoxide (100 mL) dropwise via an addition funnel. An ice water bath was used to maintain the temperature of the reaction mixture below room temperature during the addition. After 30 min the cooling bath was removed and the reaction was allowed to warm to room temperature over 2 h. The brown solution was acidified with cold 2N HCl to approximately pH 2 and extracted with ether (3×150 mL). The combined organic layers were washed with brine, dried (anhydrous magnesium sulfate) and evaporated to give 7.40 g of N-benzyloxycarbonyl-L-valinal (84.8%) as a yellow oil. The resulting material can be used without purification or further purified using column chromatography (silica gel, 9:1 hexanes:ethyl acetate).

Workup

  1. customAn ice water bath was used
  2. temperatureto maintain the temperature of the reaction mixture below room temperature
  3. additionduring the addition
  4. customAfter 30 min the cooling bath was removed
  5. extractionextracted with ether (3×150 mL)
  6. washThe combined organic layers were washed with brine
  7. dry with materialdried (anhydrous magnesium sulfate)
  8. customevaporated

Sources & evidence

ORD record
ord-4183c2d4cc884544a594828553a7965d
Source dataset
uspto-grants-1999_02
Patent number
US05874585

Reaction notes

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