N-[1-(3,4-dichlorophenyl)ethylidene]hydroxylamine → [3-(3,4-Dichloro-phenyl)-isoxazol-5-yl]-acetic acid ethyl ester

HRID 2362028Notes

Reaction equation

HRID 2362028 reaction equation
[C:1]([O:6][CH2:7][CH3:8])(=[O:5])[CH:2]=[C:3]=[CH2:4].[Cl:9][C:10]1[CH:11]=[C:12]([C:17](=[N:19][OH:20])C)[CH:13]=[CH:14][C:15]=1[Cl:16]>C(Cl)Cl>[CH2:7]([O:6][C:1](=[O:5])[CH2:2][C:3]1[O:20][N:19]=[C:17]([C:12]2[CH:13]=[CH:14][C:15]([Cl:16])=[C:10]([Cl:9])[CH:11]=2)[CH:4]=1)[CH3:8]

Participants

4

Reactant 2

HCID 2779102N-[1-(3,4-dichlorophenyl)ethylidene]hydroxylamineHCID 4066088Ethyl 2,3-butadienoate

Product 1

HCID 44632539[3-(3,4-Dichloro-phenyl)-isoxazol-5-yl]-acetic acid ethyl ester

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of ethyl 2,3-butadienoate (1 eq) and 1-(3,4-dichloro-phenyl)-ethanone oxime (1.03 eq) in DCM (51 vol) was added a 10% aqueous bleach solution (51 vol) and the resultant biphasic system stirred at room temperature for 5 days. The organic layer was separated and the aqueous layer extracted with DCM (3×7 vol). The combined organic layers were washed with water (36 vol), dried over MgSO4, filtered and concentrated. The crude residue was purified by a combination of flash column chromatography (eluent: [0:1 to 1:2] EtOAc:heptane) and prep HPLC to yield [3-(3,4-Dichloro-phenyl)-isoxazol-5-yl]-acetic acid ethyl ester.

Workup

  1. customThe organic layer was separated
  2. extractionthe aqueous layer extracted with DCM (3×7 vol)
  3. washThe combined organic layers were washed with water (36 vol)
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customThe crude residue was purified by a combination of flash column chromatography (eluent: [0:1 to 1:2] EtOAc:heptane)

Sources & evidence

ORD record
ord-cbeee150d8e34f5b801704ed2f1e9506
Source dataset
uspto-grants-2014_04
Patent number
US08691824B2

Reaction notes

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