Cyclohexanone Oxime → Benzyl 2-oxa-3-azabicyclo[2.2.1]hept-5-ene-3-carboxylate

HRID 1523227Notes

Reaction equation

[C:1]1(=[N:7][OH:8])[CH2:6][CH2:5][CH2:4][CH2:3]C1.ClCl.C([O-])([O-])=O.[Na+].[Na+].Cl[C:18]([O:20][CH2:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)=[O:19].C1CC=CC=1>O.C(OC)(C)(C)C>[CH:4]12[CH2:3][CH:1]([CH:6]=[CH:5]1)[N:7]([C:18]([O:20][CH2:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)=[O:19])[O:8]2

Participants

Conditions

Temperature: -10 °C

Procedure

Cyclohexanone oxime (20.04 g, 171.8 mmol) and methyl t-butyl ether (110 mL) were added to a reactor at 25° C. and stirred under N2 (g). The solution was cooled to −10° C. and Cl2 (g) was added during 15 min until a deep blue, clear solution was obtained. Vacuum was applied to remove remaining Cl2 and possible HCl from the reaction mixture. The temperature was set to −2° C., and a solution of Na2CO3 (11.03 g, 103 mmol) in water (90 mL) was slowly added during 30 min. The phases were separated and the organic phase transferred to a solution of Na2CO3 (19.3 g, 180.3 mmol) in water (126 mL) at 15° C. Benzyl chloroformate (32.3 g, 179.87 mmol) was added and the reaction mixture stirred for 10 min after which cyclopentadiene (25.2 g, 362.16 mmol) was added and the reaction mixture stirred for 3 h. Vacuum was applied and the remaining cyclopentadiene was removed. The phases were separated and the organic phase containing the title product was taken further directly to Example 2 as below.

Workup

customwas obtained
customto remove
customwas set to −2° C.
customThe phases were separated
additionwas added
stirringthe reaction mixture stirred for 3 h
customthe remaining cyclopentadiene was removed
customThe phases were separated
additionthe organic phase containing the title product

Sources & evidence

ORD record: ord-5577c84a0d6e4961a8d6789555c6aa31
Source dataset: uspto-grants-2015_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09079873B2

Reaction notes

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