Hydrochloric Acid → 3-(5-Fluoro-pyridin-2-yl)-isoxazole-4-carboxylic acid ethyl ester

HRID 332066Notes

Reaction equation

HRID 332066 reaction equation
ClN1C(=O)CCC1=O.[F:9][C:10]1[CH:11]=[CH:12][C:13]([CH:16]=[N:17][OH:18])=[N:14][CH:15]=1.CN([CH:22]=[CH:23][C:24]([O:26][CH2:27][CH3:28])=[O:25])C.C(N(CC)CC)C.Cl>CN(C=O)C.C(Cl)(Cl)Cl>[CH2:27]([O:26][C:24]([C:23]1[C:16]([C:13]2[CH:12]=[CH:11][C:10]([F:9])=[CH:15][N:14]=2)=[N:17][O:18][CH:22]=1)=[O:25])[CH3:28]

Participants

8

Reactant 5

HCID 313Hydrochloric AcidHCID 8471TriethylamineHCID 31398ChlorosuccinimideHCID 121015Ethyl 3-(N,N-dimethylamino)acrylateHCID 1363872515-Fluoro-pyridine-2-carbaldehyde oxime

Product 1

HCID 666436143-(5-Fluoro-pyridin-2-yl)-isoxazole-4-carboxylic acid ethyl esterYield 72%

Reagents, catalysts & solvents 2

HCID 6212ChloroformSolventHCID 6228DimethylformamideSolvent

Conditions

Temperature
60 °C

Procedure

To a solution of N-chlorosuccinimide (17.34 g, 130 mmol) in DMF (128 mL) was added 5-fluoro-pyridine-2-carbaldehyde oxime (18.2 g, 130 mmol) portionwise over 2 h at room temperature and as the reaction warmed up to 60° C. the mixture was cooled back to room temperature with an ice-water bath and the resulting mixture was then stirred for 64 h at room temperature. To this solution was then added ethyl 3-(N,N-dimethylamino)acrylate (18.6 g, 130 mmol) and triethylamine (36.2 mL, 260 mmol) in chloroform (64 mL) and the resulting mixture was then stirred for 1 h at room temperature and poured onto a mixture of ice water and HCl (4 N, 1 L) and extracted with ethylacetate. The organic extract was then washed with water, saturated aqueous sodium hydrogen carbonate solution, brine, dried with sodium sulfate, filtered and evaporated. Purification by chromatography (SiO2, heptane:ethylacetate=100:0 to 1:1) afforded the title product (21.96 g, 72%) which was obtained as a yellow solid. MS: m/e=237.1 [M+H]+.

Workup

  1. temperaturewas cooled back to room temperature with an ice-water bath
  2. extractionextracted with ethylacetate
  3. extractionThe organic extract
  4. washwas then washed with water, saturated aqueous sodium hydrogen carbonate solution, brine
  5. dry with materialdried with sodium sulfate
  6. filtrationfiltered
  7. customevaporated
  8. customPurification by chromatography (SiO2, heptane:ethylacetate=100:0 to 1:1)

Sources & evidence

ORD record
ord-e9eb06008e754ce2a7d16babaa1dbdbf
Source dataset
uspto-grants-2014_11
Patent number
US08877782B2

Reaction notes

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