Acetic Anhydride → 2-methyl-4-(3-pyridinylmethylene)-5(4H)-oxazolone

HRID 7202

Reaction equation

HRID 7202 reaction equation
[N:1]1[CH:6]=[CH:5][CH:4]=[C:3]([CH:7]=O)[CH:2]=1.[C:9]([NH:12][CH2:13][C:14]([OH:16])=[O:15])(=O)[CH3:10].C([O-])(=O)C.[Na+].C(OC(=O)C)(=O)C>C(OC)(C)(C)C.CC(C)=O>[CH3:10][C:9]1[O:16][C:14](=[O:15])/[C:13](=[CH:7]/[C:3]2[CH:2]=[N:1][CH:6]=[CH:5][CH:4]=2)/[N:12]=1

Participants

7

Reactant 4

HCID 7918Acetic AnhydrideHCID 103713-PyridinecarboxaldehydeHCID 10972AcetylglycineHCID 517045Sodium Acetate

Product 1

HCID 17316032-methyl-4-(3-pyridinylmethylene)-5(4H)-oxazolone

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 15413tert-Butyl methyl etherSolvent

Conditions

Temperature
50 °C

Procedure

Under nitrogen, acetone (40.0 l), followed by pyridine-3-carbaldehyde (20.0 kg, 186.9 mol), was added to N-acetylglycine (32.7 kg, 280.0 mol) and sodium acetate (15.3 kg, 186.9 mol). With stirring, acetic anhydride (40.0 l, 429.0 mol) was added. Within 30 min, the reaction mixture was heated to reflux temperature and then stirred under reflux for 1.5 h. This gave a thin reddish suspension. The suspension was cooled to 50° C., and methyl tert-butyl ether (80.0 l) was then added. Ice-water (<2° C., 200.0 l) was added as quickly as possible (<5 min), with stirring and cooling, and the mixture was then stirred at 5–10° C. for 1 h. The beige suspension was introduced into a centrifuge which had been inertized with nitrogen. The precipitate was centrifuged, washed with deionized water (80.0 l) and dried under reduced pressure at 40° C. Yield: 24.8 kg (131.9 mol, 70.6% of theory). M.p.: 173° C.; MS (DCl): m/z (%)=189 ([M+H+], 100); 1H-NMR (200 MHz, DMSO-d6): δ=2.40 (s, 3H), 7.28 (s, 1H), 7.53 (dd, 1H), 8.61 (d, 2H), 9.18 (brs, 1H); IR (KBr): ν=1799.9, 1777.4, 898.0 cm−1.

Workup

  1. temperaturethe reaction mixture was heated
  2. temperatureto reflux temperature
  3. stirringstirred
  4. temperatureunder reflux for 1.5 h
  5. customThis gave a thin reddish suspension
  6. stirringwith stirring
  7. temperaturecooling
  8. stirringthe mixture was then stirred at 5–10° C. for 1 h
  9. additionThe beige suspension was introduced into a centrifuge which
  10. washwashed with deionized water (80.0 l)
  11. customdried under reduced pressure at 40° C

Sources & evidence

ORD record
ord-1f1fb938305c4ba3a172d5108b3d713d
Source dataset
uspto-grants-2006_08
Patent number
US07084250B2

Linked notes

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