Lithium (trimethylsilyl)acetylide → Tert-butyl N-[1-(prop-2-ynoyl)cyclopropyl]carbamate

HRID 1040482Notes

Reaction equation

HRID 1040482 reaction equation
[C:1]([O:5][C:6](=[O:17])[NH:7][C:8]1([C:11](=[O:16])N(OC)C)[CH2:10][CH2:9]1)([CH3:4])([CH3:3])[CH3:2].[Li+].C[Si]([C:23]#[C-:24])(C)C>C1COCC1.[NH4+].[Cl-]>[C:1]([O:5][C:6](=[O:17])[NH:7][C:8]1([C:11](=[O:16])[C:23]#[CH:24])[CH2:9][CH2:10]1)([CH3:2])([CH3:3])[CH3:4]

Participants

5

Reactant 2

HCID 3431600Lithium (trimethylsilyl)acetylide2×HCID 15234151Tert-butyl 1-(methoxy(methyl)carbamoyl)cyclopropylcarbamate

Product 1

HCID 86646201Tert-butyl N-[1-(prop-2-ynoyl)cyclopropyl]carbamateYield 12.8%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 25517Ammonium ChlorideSolvent

Procedure

To a solution of [1-(Methoxy-methyl-carbamoyl)-cyclopropyl]-carbamic acid tert-butyl ester (5.0 g, 20. mmol) in anhydrous THF (50 mL) at −78° C., was slowly added lithium (trimethylsilyl)acetylide (0.5 M in THF, 81 mL, 41 mmol). The reaction stirred at this temperature for 2 h then an additional amount of lithium (trimethylsilyl)acetylide (0.5 M in THF, 81 mL, 41 mmol) was added and stirring continued for 3 h at −78° C. The reaction was diluted with saturated aqueous NH4Cl and extracted with EtOAc. The organic layer was washed with brine, dried over Na2SO4, and concentrated in vacuo. The material was purified by flash chromatography (silica, 15% EtOAc/petroleum ether) to give 550 mg of the title compound as a brown syrup, m/z 154.18 [M-t-Bu]+.

Workup

  1. customat −78° C.
  2. stirringstirring
  3. waitcontinued for 3 h at −78° C
  4. extractionextracted with EtOAc
  5. washThe organic layer was washed with brine
  6. dry with materialdried over Na2SO4
  7. concentrationconcentrated in vacuo
  8. customThe material was purified by flash chromatography (silica, 15% EtOAc/petroleum ether)

Sources & evidence

ORD record
ord-6a59d07ea93942a6a1679d9299956783
Source dataset
uspto-grants-2013_10
Patent number
US08552205B2

Reaction notes

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