Boron trifluoride etherate → HCID 57213227, compound

HRID 482834Notes

Reaction equation

HRID 482834 reaction equation
C([O:8][CH2:9][CH2:10][CH:11]1[NH:14][C:13](=[O:15])[CH:12]1[CH2:16][CH3:17])C1C=CC=CC=1.CO[C:20]([CH3:22])=[CH2:21].B(F)(F)F.CCOCC.[CH3:32][C:33]([CH3:36])([O-])[CH3:34].[K+]>C1(C)C=CC=CC=1.C(O)(=O)C>[CH2:32]([C:9](=[O:8])[CH2:10][CH:11]1[NH:14][C:13](=[O:15])[CH:12]1[CH2:16][CH3:17])[C:33]1[CH:36]=[CH:22][CH:20]=[CH:21][CH:34]=1

Participants

7

Reactant 4

HCID 8000Boron trifluoride etherateHCID 83002-MethoxypropeneHCID 20243492HCID 20243492, compoundHCID 23665647Potassium tert-butoxide

Product 1

HCID 57213227HCID 57213227, compound

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 1140TolueneSolvent

Procedure

A mixture of 4-(2-benzyloxyethyl)-3-ethyl-2-azetidinone (11.65 g), 2-methoxypropene (7.1 ml), borontrifluoride etherate (0.5 ml) in anhydrous toluene (87 ml) is stirred at room temperature for 31/2 hours. Then potassium t-butoxide (3.13 g) is added at room temperature monitoring the epimerization by means of gas-chromatographic assays. After one hour, 40% acetic acid (30 ml) is added and the mixture is heated to 75° C. for two hours and allowed to stand at room temperature overnight. The aqueous acidic phase which separates is extracted with toluene (two 30-ml portions) and the toluene extracts are combined, dried over Na2SO4 and concentrated to dryness under vacuum yielding 10.5 g of crude 4-(2-benzyloxoethyl)-3-ethyl-2-azetidinone which contains 90% of the trans-isomer (estimated by N.M.R.).

Workup

  1. waitAfter one hour
  2. temperaturethe mixture is heated to 75° C. for two hours
  3. waitto stand at room temperature overnight
  4. extractionThe aqueous acidic phase which separates is extracted with toluene (two 30-ml portions)
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated to dryness under vacuum

Sources & evidence

ORD record
ord-48891f5e3f18498780117600cef5894c
Source dataset
uspto-grants-1986_03
Patent number
US04576746

Reaction notes

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