Imidazole → Ethyl (S)-(-)-2-(tert-butyldimethylsilyloxy)propionate

HRID 1027151Notes

Reaction equation

HRID 1027151 reaction equation
[C:1]([O:6][CH2:7][CH3:8])(=[O:5])[C@H:2]([CH3:4])[OH:3].N1C=CN=C1.[Si:14](Cl)([C:17]([CH3:20])([CH3:19])[CH3:18])([CH3:16])[CH3:15]>CN(C=O)C.O>[Si:14]([O:3][C@@H:2]([CH3:4])[C:1]([O:6][CH2:7][CH3:8])=[O:5])([C:17]([CH3:20])([CH3:19])[CH3:18])([CH3:16])[CH3:15]

Participants

6

Reactant 3

HCID 795ImidazoleHCID 28928tert-Butyldimethylsilyl chlorideHCID 92831(L)-ethyl lactate

Product 1

HCID 10966394Ethyl (S)-(-)-2-(tert-butyldimethylsilyloxy)propionateYield 95%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Procedure

To a solution of (S)-ethyl lactate (11.8 g, 100 mmol) in DMF (50 mL) was added imidazole (10.2 g, 150 mmol). The mixture was cooled in an ice bath and tert-butyldimethylsilyl chloride (15.8 g, 105 mmol) was added in three portions, at intervals of 30 min between each addition. The reaction mixture was stirred overnight. The reaction mixture was diluted with water (30 mL) and extracted with Et2O (50 mL×2). The combined extracts were washed with brine, dried over MgSO4 and concentrated in vacuo. The residue was distilled under vacuum (bp 70-78° C., 0.5 mmHg) to afford 22.07 g (95%) of (S)-ethyl 2-(tert-butyldimethylsilyloxy)propanoate: 1H NMR (400 MHz, CHLOROFORM-d) δ 4.32 (q, J=6.6 Hz, 1H), 4.11-4.25 (m, 2H), 1.40 (d, J=6.6 Hz, 3H), 1.29 (t, J=7.1 Hz, 3H), 0.93 (s, 9H), 0.12 (s, 3H), 0.09 (s, 3H).

Workup

  1. temperatureThe mixture was cooled in an ice bath
  2. extractionextracted with Et2O (50 mL×2)
  3. washThe combined extracts were washed with brine
  4. dry with materialdried over MgSO4
  5. concentrationconcentrated in vacuo
  6. distillationThe residue was distilled under vacuum (bp 70-78° C., 0.5 mmHg)

Sources & evidence

ORD record
ord-2737e492261e47c29b8817902c7f054d
Source dataset
uspto-grants-2014_05
Patent number
US08729263B2

Reaction notes

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