Diphosgene → 1-Benzyl-1H-pyrido[2,3-d][1,3]oxazine-2,4-dione

HRID 901227Notes

Reaction equation

HRID 901227 reaction equation
Cl[C:2](OC(Cl)(Cl)Cl)=[O:3].[CH2:9]([NH:16][C:17]1[N:25]=[CH:24][CH:23]=[CH:22][C:18]=1[C:19]([OH:21])=[O:20])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1>O1CCOCC1>[CH2:9]([N:16]1[C:17]2[N:25]=[CH:24][CH:23]=[CH:22][C:18]=2[C:19](=[O:21])[O:20][C:2]1=[O:3])[C:10]1[CH:11]=[CH:12][CH:13]=[CH:14][CH:15]=1

Participants

4

Reactant 2

HCID 10426DiphosgeneHCID 2145962-(Benzylamino)nicotinic acid

Product 1

HCID 134251031-Benzyl-1H-pyrido[2,3-d][1,3]oxazine-2,4-dioneYield 68%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

Trichloromethyl chloroformate (2.5 mL, 21 mmol) was added slowly to a suspension of (1) (4 g, 17.5 mmol) in dioxane and refluxed for 8 h under nitrogen atmosphere. The solution was cooled and the solvent was removed under vacuum. The residue was dissolved in dichloromethane and washed by saturated NaHCO3 solution. The organic phase was dried over Na2SO4 and evaporated to yield a residue. The residue was recrystallized by ether to yields 3.02 g (68%) of 1-benzyl-1H-pyrido[2,3-d][1,3]oxazine-2,4-dione (2) as white solids. MP: 168° C.; 1H-NMR (DMSO-d6): δ 5.35 (s, 2H), 7.26 (m, 1H), 7.30 (m, 2H), 7.39 (m, 3H), 8.41 (dd, J=1.5, 7.5 Hz, 1H), 8.72 (dd, J=1.5, 7.5 Hz, 1H); EIMS: 277 (M+23).

Workup

  1. temperaturerefluxed for 8 h under nitrogen atmosphere
  2. temperatureThe solution was cooled
  3. customthe solvent was removed under vacuum
  4. dissolutionThe residue was dissolved in dichloromethane
  5. washwashed by saturated NaHCO3 solution
  6. dry with materialThe organic phase was dried over Na2SO4
  7. customevaporated
  8. customto yield a residue
  9. customThe residue was recrystallized by ether

Sources & evidence

ORD record
ord-674e6b8ecaf94baf910a6d5e3e182152
Source dataset
uspto-grants-2008_04
Patent number
US07361760B2

Reaction notes

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