Ethyl 2-(2-(4-nitrophenyl)-2-oxoethylamino)-2-oxoacetate → Ethyl 5-(4-nitrophenyl)-1,3-oxazole-2-carboxylate

HRID 1024425Notes

Reaction equation

HRID 1024425 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([C:10](=[O:20])[CH2:11][NH:12][C:13](=O)[C:14]([O:16][CH2:17][CH3:18])=[O:15])=[CH:6][CH:5]=1)([O-:3])=[O:2]>O=P(Cl)(Cl)Cl>[N+:1]([C:4]1[CH:5]=[CH:6][C:7]([C:10]2[O:20][C:13]([C:14]([O:16][CH2:17][CH3:18])=[O:15])=[N:12][CH:11]=2)=[CH:8][CH:9]=1)([O-:3])=[O:2]

Participants

3

Reactant 1

HCID 66572182Ethyl 2-(2-(4-nitrophenyl)-2-oxoethylamino)-2-oxoacetate

Product 1

HCID 22350462Ethyl 5-(4-nitrophenyl)-1,3-oxazole-2-carboxylateYield 60.6%

Reagents, catalysts & solvents 1

HCID 24813Phosphorus oxychlorideSolvent

Procedure

A solution of Ethyl 2-(2-(4-nitrophenyl)-2-oxoethylamino)-2-oxoacetate (step C product, 8.5 g) in POCl3 (55 ml) was refluxed for 6 hours. The reaction mixture was cooled, quenched with ice and neutralized with sodium carbonate. DCM was added to it and the organic and aqueous layers were separated. Organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure to get dark brown residue. The residue was chromatographed on silica gel in 2:8 Ethyl acetate:Pet ether to get pale brown colored solid which was crystallized in chloroform/pet ether to yield 4.82 g (60%) of the title compound. 1HNMR (CDCl3, 300 MHz): δ 8.41 (d, 2H), 7.97 (d, 2H), 7.37 (s, 1H), 4.55 (q, 2H), 1.49 (t, 3H).

Workup

  1. temperatureThe reaction mixture was cooled
  2. customquenched with ice and neutralized with sodium carbonate
  3. additionDCM was added to it
  4. customthe organic and aqueous layers were separated
  5. dry with materialOrganic layer was dried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure
  8. customto get dark brown residue
  9. customThe residue was chromatographed on silica gel in 2:8 Ethyl acetate
  10. customPet ether to get pale brown colored solid which
  11. customwas crystallized in chloroform/pet ether

Sources & evidence

ORD record
ord-8ebde046958945349795d9e368f9fe89
Source dataset
uspto-grants-2014_05
Patent number
US08722901B2

Reaction notes

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