Water → Ethyl 5-(2,5-dimethoxybenzyl)-1,2,4-oxadiazole-3-carboxylate

HRID 58611

Reaction equation

HRID 58611 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([O:9][CH3:10])=[CH:5][C:4]=1[CH2:11][C:12](Cl)=[O:13].[NH2:15][C:16](=[N:22]O)[C:17]([O:19][CH2:20][CH3:21])=[O:18].C(N(CC)C(C)C)(C)C.O>ClCCl>[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([O:9][CH3:10])=[CH:5][C:4]=1[CH2:11][C:12]1[O:13][N:22]=[C:16]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[N:15]=1

Participants

6

Reactant 4

HCID 962WaterHCID 81531DiisopropylethylamineHCID 596088(2,5-Dimethoxyphenyl)acetyl chlorideHCID 6785548Ethyl 2-amino-2-(hydroxyimino)acetate

Product 1

HCID 66832124Ethyl 5-(2,5-dimethoxybenzyl)-1,2,4-oxadiazole-3-carboxylateYield 37.5%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

2-(2,5-dimethoxyphenyl)acetyl chloride (0.662 mL; 3.78 mmol) was added to a mixture of ethyl 2-amino-2-(hydroxyimino)acetate (0.500 g; 3.78 mmol) and N,N diisopropylethylamine (1.05 mL; 6.06 mmol) in dichloromethane (18 mL) at −15° C. The reaction mixture was stirred at room temperature overnight and poured into a mixture of ice and water. The formed precipitate was filtered off, suspended in pyridine (18 mL) and refluxed in a sealed tube for 20 h and concentrated under reduced pressure. The crude material was purified by flash chromatography on silica (eluent 20 to 100% ethyl acetate in heptane) to yield 0.414 g (37%) of ethyl 5-(2,5-dimethoxybenzyl)-1,2,4-oxadiazole-3-carboxylate as a yellow oil.

Workup

  1. filtrationThe formed precipitate was filtered off
  2. temperaturerefluxed in a sealed tube for 20 h
  3. concentrationconcentrated under reduced pressure
  4. customThe crude material was purified by flash chromatography on silica (eluent 20 to 100% ethyl acetate in heptane)

Sources & evidence

ORD record
ord-afbe7050054a4dcbb592ce5a267bdfc2
Source dataset
uspto-grants-2016_09
Patent number
US09434722B2

Linked notes

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