Nitroethane → Ethyl 3,5-dimethylisoxazole-4-carboxylate

HRID 1287301

Reaction equation

HRID 1287301 reaction equation
N1(/[C:6](/[CH3:13])=[CH:7]\[C:8]([O:10][CH2:11][CH3:12])=[O:9])CCCC1.[N+:14]([CH2:17][CH3:18])([O-:16])=O.C(N(CC)CC)C.P(Cl)(Cl)(Cl)=O>C(Cl)(Cl)Cl>[C:8]([C:7]1[C:17]([CH3:18])=[N:14][O:16][C:6]=1[CH3:13])([O:10][CH2:11][CH3:12])=[O:9]

Participants

6

Reactant 4

HCID 6587NitroethaneHCID 8471TriethylamineHCID 24813Phosphorus oxychlorideHCID 736204Ethyl 3-pyrrolidinocrotonate

Product 1

HCID 736348Ethyl 3,5-dimethylisoxazole-4-carboxylate

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent2×

Procedure

A solution of the ethyl β-pyrrolidinocrotonate (427 g. = 2.33 moles), 190 ml. (182 g., 2.43 mole) of nitroethane and 1300 ml. of triethylamine in 1200 ml. of anhydrous chloroform was cooled in an ice bath under nitrogen. A solution of 235 ml. (393 g. = 2.56 mole) of phosphorus oxychloride in 400 ml. of chloroform was added at such a rate that the temperature did not rise above 15°. During the addition, which took place over a three-hour period, a viscous orange precipitate formed. This suspension was then stirred under nitrogen overnight. As much solvent as possible was removed at reduced pressure and the resulting red-brown paste was diluted with water and extracted with ether. The ether solutions were washed sequentially with water, 3N hydrochloric acid, water, 5 percent sodium hydroxide solution and water, and were dried over anhydrous sodium sulfate. Solvent removal at reduced pressure gave a dark oil which was distilled through a short Vigreux column to give 4-carboethoxy-3,5-dimethyl-isoxazole as a slightly cloudy, colorless liquid of b.p. 100°/11 mm.

Workup

  1. customdid not rise above 15°
  2. additionDuring the addition, which
  3. customa viscous orange precipitate formed
  4. customAs much solvent as possible was removed at reduced pressure
  5. additionthe resulting red-brown paste was diluted with water
  6. extractionextracted with ether
  7. washThe ether solutions were washed sequentially with water, 3N hydrochloric acid, water, 5 percent sodium hydroxide solution and water
  8. dry with materialwere dried over anhydrous sodium sulfate
  9. customSolvent removal at reduced pressure
  10. customgave a dark oil which
  11. distillationwas distilled through a short Vigreux column

Sources & evidence

ORD record
ord-ea240d4ec50f4dddb22578f9da608761
Source dataset
uspto-grants-1976_10
Patent number
US03984427

Linked notes

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