3-Oxo-azetidine-1-carboxylic acid tert-butyl ester → tert-Butyl 3-methylideneazetidine-1-carboxylate

HRID 2040855Notes

Reaction equation

HRID 2040855 reaction equation
[CH3:1]C([O-])(C)C.[K+].[C:7]([O:11][C:12]([N:14]1[CH2:17][C:16](=O)[CH2:15]1)=[O:13])([CH3:10])([CH3:9])[CH3:8]>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.CCOCC>[CH2:1]=[C:16]1[CH2:17][N:14]([C:12]([O:11][C:7]([CH3:10])([CH3:9])[CH3:8])=[O:13])[CH2:15]1

Participants

5

Reactant 2

HCID 15194043-Oxo-azetidine-1-carboxylic acid tert-butyl esterHCID 23665647Potassium tert-butoxide

Product 1

HCID 55269097tert-Butyl 3-methylideneazetidine-1-carboxylateYield 86.2%

Reagents, catalysts & solvents 2

HCID 74505Methyltriphenyliphosphonium bromideCatalystHCID 3283Diethyl EtherSolvent

Conditions

Temperature
0 °C

Procedure

To a suspension of methyltriphenylphosphonium bromide (1.56 g, 4.37 mmol) in 30 mL of Et2O stirred at 0° C. was added potassium tert-butylate (0.459 g, 4.09 mmol). After 0.5 h the cold bath was removed and the mixture was stirred for 1 h at r.t. Afterwards, it was cooled off in water-ice bath, and 3-oxo-azetidine-1-carboxylic acid tert-butyl ester (500 mg, 2.92 mmol) was added. The cold bath was removed. After overnight resting, the reaction mixture was quenched with a saturated solution of NH4Cl in water, extracted with Et2O, dried on Na2SO4, evaporated to dryness in vacuo, dissolvent. The residual crude was purified by automated flash chromatography (SP1®TM-Biotage; gradient Petroleum Ether-Acetone from 10:0 to 7:3) to give the title compound (426 mg) as a dense colourless oil. Yield: 86.2%

Workup

  1. customAfter 0.5 h the cold bath was removed
  2. stirringthe mixture was stirred for 1 h at r.t
  3. temperatureAfterwards, it was cooled off in water-ice bath
  4. customThe cold bath was removed
  5. customthe reaction mixture was quenched with a saturated solution of NH4Cl in water
  6. extractionextracted with Et2O
  7. customdried on Na2SO4
  8. customevaporated to dryness in vacuo
  9. dissolutiondissolvent
  10. customThe residual crude was purified by automated flash chromatography (SP1®TM-Biotage; gradient Petroleum Ether-Acetone from 10:0 to 7:3)

Sources & evidence

ORD record
ord-44ec1858f1674d769e33ae258b6320b5
Source dataset
uspto-grants-2013_11
Patent number
US08580962B2

Reaction notes

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