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

HRID 605724Notes

Reaction equation

HRID 605724 reaction equation
[CH3:1][C:2](C)([O-])C.[K+].O=[C:8]1[CH2:11][N:10]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:9]1>[Br-].C([P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)C.CCOCC>[CH:1](=[C:8]1[CH2:11][N:10]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:9]1)[CH3:2]

Participants

5

Reactant 2

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

Product 1

HCID 52180841tert-Butyl 3-ethylideneazetidine-1-carboxylateYield 49%

Reagents, catalysts & solvents 2

HCID 73727Phosphonium, ethyltriphenyl-, bromide (1:1)CatalystHCID 3283Diethyl EtherSolvent2×

Procedure

Potassium tert-butoxide (1.672 g, 14.9 mmol) and ethyltriphenylphosphonium bromide (5.538 g, 14.9 mmol) were stirred in ether (30 mL) at amibient for 1 h. 1,1-Dimethylethyl 3-oxoazetidine-1-carboxylate (954 mg, 6.0 mmol), prepared using procedures similar to those described in Example 3, was added and the mixture was 35° C. for 4.5 h. Mixture was filtered through celite and the solid was washed with ether. The filtrate was washed with water, brine, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. Column chromatography (silica gel, 20% ether in hexanes) gave 1,1-dimethylethyl 3-ethylideneazetidine-1-carboxylate (506 mg, 2.76 mmol, 49% yield): 1H NMR (400 MHz, CDCl3): 5.37-5.28 (m, 1H), 4.47-4.39 (m, 4H), 1.56-1.51 (m, 3H), 1.45 (s, 9H).

Workup

  1. additionwas added
  2. filtrationMixture was filtered through celite
  3. washthe solid was washed with ether
  4. washThe filtrate was washed with water, brine
  5. dry with materialdried over anhydrous sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-275ce705b59643dfa882ba524bd9c8ee
Source dataset
uspto-grants-2011_03
Patent number
US07915250B2

Reaction notes

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