Cyclopentadiene → Tert-butyl 2-oxa-3-azabicyclo[2.2.1]hept-5-ene-3-carboxylate

HRID 931483Notes

Reaction equation

HRID 931483 reaction equation
[OH:1][NH:2][C:3](=[O:9])[O:4][C:5]([CH3:8])([CH3:7])[CH3:6].[CH:10]1[CH2:14][CH:13]=[CH:12][CH:11]=1.I([O-])(=O)(=O)=O.[Na+]>CO.O>[CH:12]12[CH2:13][CH:14]([CH:10]=[CH:11]1)[N:2]([C:3]([O:4][C:5]([CH3:8])([CH3:7])[CH3:6])=[O:9])[O:1]2

Participants

6

Reactant 3

HCID 7612CyclopentadieneHCID 97534tert-butyl N-hydroxycarbamateHCID 23667635Sodium periodate

Product 1

HCID 15332365Tert-butyl 2-oxa-3-azabicyclo[2.2.1]hept-5-ene-3-carboxylateYield 67%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent2×

Procedure

To a solution of tert-butyl N-hydroxycarbamate (9.2 g, 69.10 mmol, 1.00 equiv) and cyclopenta-1,3-diene (20.2 g, 305.59 mmol, 4.42 equiv) in methanol (600 mL) was added of a solution of sodium periodate (17 g, 79.48 mmol, 1.15 equiv) in water (180 mL) dropwise at 0° C. with stirring in 30 min. The reaction mixture was stirred for another 30 min at 0° C. and then diluted with 600 mL of water. The solution was extracted with 3×300 mL of ethyl acetate. The combined organic layers was washed with 2×200 mL of brine, dried over anhydrous sodium sulfate and concentrated under vacuum to give 9.1 g (67%) of tert-butyl 2-oxa-3-azabicyclo[2.2.1]hept-5-ene-3-carboxylate as a white solid. 1HNMR (400 MHz, D2O, ppm) δ 6.42 (2H, s), 5.22 (1H, s), 4.99 (1H, s), 1.99 (1H, d, J=8.4 Hz), 1.73 (1H, d, J=8.4 Hz), 1.47 (9H, s).

Workup

  1. stirringThe reaction mixture was stirred for another 30 min at 0° C.
  2. extractionThe solution was extracted with 3×300 mL of ethyl acetate
  3. washThe combined organic layers was washed with 2×200 mL of brine
  4. dry with materialdried over anhydrous sodium sulfate
  5. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-bdcd0eb314954c95913bbf80359c014b
Source dataset
uspto-grants-2016_03
Patent number
US09296732B2

Reaction notes

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