Triethylamine → 3-(4-Chloro-pyridin-3-yl)-5-methyl-isoxazole-4-carboxylic acid ethyl ester

HRID 1823278Notes

Reaction equation

HRID 1823278 reaction equation
Cl[C:2]([C:5]1[CH:6]=[N:7][CH:8]=[CH:9][C:10]=1[Cl:11])=[N:3][OH:4].[CH2:12]([O:14][C:15](=[O:19])[C:16]#[C:17][CH3:18])[CH3:13].C(N(CC)CC)C>C(OCC)C>[CH2:12]([O:14][C:15]([C:16]1[C:2]([C:5]2[CH:6]=[N:7][CH:8]=[CH:9][C:10]=2[Cl:11])=[N:3][O:4][C:17]=1[CH3:18])=[O:19])[CH3:13]

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 78043Ethyl 2-butynoateHCID 738675804-Chloro-N-hydroxy-3-pyridinecarboximidoyl chloride

Product 1

HCID 574254393-(4-Chloro-pyridin-3-yl)-5-methyl-isoxazole-4-carboxylic acid ethyl esterYield 27.4%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

Combine chloro(4-chloro(3-pyridyl))(hydroxyimino)methane (2.40 g, 0.013 mol) with ethyl-2-butynoate (3.66 mL, 0.031 mol) in diethyl ether (150 mL) under a nitrogen atmosphere. Add triethylamine (2.27 mL, 0.016 mol) in a dropwise manner and stir over a weekend at ambient temperature. Quench the mixture with water and extract with ethyl acetate. Concentrate the combined extracts and elute over silica gel with methanol/dichloromethane to give the desired isoxazole (0.95 g, 27%) as an oil. ES(EI): M+ 266.0, 267.0, 268.0 m/z.

Workup

  1. customQuench the mixture with water
  2. extractionextract with ethyl acetate
  3. concentrationConcentrate the combined extracts
  4. washelute over silica gel with methanol/dichloromethane

Sources & evidence

ORD record
ord-64678e4d4f7a4217ba5d594e64c3b07d
Source dataset
uspto-grants-2006_05
Patent number
US07037921B2

Reaction notes

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