Diphosgene → 2H-Pyrido[4,3-d][1,3]oxazine-2,4(1H)-dione

HRID 901295Notes

Reaction equation

HRID 901295 reaction equation
ClC(OC(Cl)(Cl)Cl)=O.C(O[C:14]([NH:16][C:17]1[C:22]([C:23]([OH:25])=[O:24])=[CH:21][N:20]=[CH:19][CH:18]=1)=[O:15])(C)(C)C>O1CCOCC1>[NH:16]1[C:17]2[CH:18]=[CH:19][N:20]=[CH:21][C:22]=2[C:23](=[O:24])[O:25][C:14]1=[O:15]

Participants

4

Reactant 2

HCID 10426DiphosgeneHCID 221726234-{[(Tert-butoxy)carbonyl]amino}pyridine-3-carboxylic acid

Product 1

HCID 107970962H-Pyrido[4,3-d][1,3]oxazine-2,4(1H)-dioneYield 98%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

Trichloromethyl chloroformate (9 mL, 75 mmol) was added slowly to a solution of 4-tert-butoxycarbonylamino-nicotinic acid (118) (16.2 g, 68 mmol) in dioxane and refluxed for 4 h under nitrogen atmosphere. The solution was cooled and the solvent was removed under vacuum. The residue was recrystallized by ether to yield 10.92 g (98%) of 1H-pyrido[4,3-d][1,3]oxazine-2,4-dione (119) as white solids. MP: 243° C.; 1H-NMR (DMSO-d6): ), δ 7.32 (d, J=6.0 Hz, 1H), 8.71 (d, J=6.0 Hz, 1H), 9.11 (s, 1H); EIMS m/z 165 (M+1).

Workup

  1. temperaturerefluxed for 4 h under nitrogen atmosphere
  2. temperatureThe solution was cooled
  3. customthe solvent was removed under vacuum
  4. customThe residue was recrystallized by ether

Sources & evidence

ORD record
ord-dabbb95afcf14a8b8707030896564487
Source dataset
uspto-grants-2008_04
Patent number
US07361760B2

Reaction notes

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