Acetic Anhydride → Ethyl 1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-7-methoxy-4-oxo-1,8-naphthyridine-3-carboxylate

HRID 232482Notes

Reaction equation

HRID 232482 reaction equation
[F:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[CH:4][C:3]=1[NH:9][C:10]1[N:23]=[C:22]([O:24][CH3:25])[C:21]([F:26])=[CH:20][C:11]=1[C:12]([CH2:14][C:15]([O:17][CH2:18][CH3:19])=[O:16])=[O:13].[C:27](OC(=O)C)(=O)C.C([O-])([O-])OCC.C(OCC)(=O)C>O1CCOCC1.C(OCC)C.O>[F:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[CH:4][C:3]=1[N:9]1[C:10]2[C:11](=[CH:20][C:21]([F:26])=[C:22]([O:24][CH3:25])[N:23]=2)[C:12](=[O:13])[C:14]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[CH:27]1

Participants

8

Reactant 4

HCID 7918Acetic AnhydrideHCID 8857Ethyl AcetateHCID 15596920Ethyl 2-[2-(2,4-difluorophenylamino)-5-fluoro-6-methoxynicotinoyl]acetateHCID 53630039Ethylorthoformate

Product 1

HCID 13849333Ethyl 1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-7-methoxy-4-oxo-1,8-naphthyridine-3-carboxylateYield 43.8%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 3283Diethyl EtherSolventHCID 312751,4-DioxaneSolvent

Procedure

In 1 ml of dioxane were dissolved 100 mg of ethyl 2-[2-(2,4-difluorophenylamino)-5-fluoro-6-methoxynicotinoyl]acetate, 55 mg of acetic anhydride and 60 mg of ethyl ortho-formate, and the resulting solution was subjected to reaction under reflux for 7 hours. Subsequently, the reaction mixture was added to a mixture of 3 ml of ethyl acetate and 3 ml of water, and the organic layer was separated, washed successively with 3 ml of water and 3 ml of saturated aqueous sodium chloride solution, and then dried over anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure, and to the crystalline material thus obtained was added 1 ml of diethyl ether, after which crystals were collected by filtration to obtain 45 mg (yield 43.8%) of ethyl 1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-7-methoxy-4-oxo-1,8-naphthyridine-3-carboxylate. The physical properties of this compound were identical with those of the compound obtained in Example 41.

Workup

  1. customthe resulting solution was subjected to reaction
  2. temperatureunder reflux for 7 hours
  3. customthe organic layer was separated
  4. washwashed successively with 3 ml of water and 3 ml of saturated aqueous sodium chloride solution
  5. dry with materialdried over anhydrous magnesium sulfate
  6. customThe solvent was removed by distillation under reduced pressure
  7. customto the crystalline material thus obtained
  8. filtrationafter which crystals were collected by filtration

Sources & evidence

ORD record
ord-ff3e27c82c4842a9abdb3d4cdf15e521
Source dataset
uspto-grants-1989_07
Patent number
US04851535

Reaction notes

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