Phosphorus oxychloride → Ethyl 7-chloro-1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylate

HRID 246972Notes

Reaction equation

HRID 246972 reaction equation
[F:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[CH:4][C:3]=1[N:9]1[C:18]2[C:13](=[CH:14][C:15]([F:21])=[C:16](OC)[N:17]=2)[C:12](=[O:22])[C:11]([C:23]([O:25][CH2:26][CH3:27])=[O:24])=[CH:10]1.P(Cl)(Cl)([Cl:30])=O>>[Cl:30][C:16]1[N:17]=[C:18]2[C:13]([C:12](=[O:22])[C:11]([C:23]([O:25][CH2:26][CH3:27])=[O:24])=[CH:10][N:9]2[C:3]2[CH:4]=[CH:5][C:6]([F:8])=[CH:7][C:2]=2[F:1])=[CH:14][C:15]=1[F:21]

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 13849333Ethyl 1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-7-methoxy-4-oxo-1,8-naphthyridine-3-carboxylate

Product 1

HCID 1268243Ethyl 7-chloro-1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylateYield 85%

Procedure

In 2.5 ml of phosphorus oxychloride was suspended 500 mg of ethyl 1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-7-methoxy-4-oxo-1,8-naphthyridine-3-carboxylate, and the resulting suspension was subjected to reaction under reflux for 1.5 hours. Subsequently, the solvent was removed by distillation under reduced pressure, and the crystalline material thus obtained was washed with 10 ml of diethyl ether to obtain 430 mg (yield 85.0%) of ethyl 7-chloro-1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylate having a melting point of 216°-219° C. The physical properties of this compound were identical with those of the compound obtained in Example 51.

Workup

  1. customthe resulting suspension was subjected to reaction
  2. temperatureunder reflux for 1.5 hours
  3. customSubsequently, the solvent was removed by distillation under reduced pressure
  4. customthe crystalline material thus obtained
  5. washwas washed with 10 ml of diethyl ether

Sources & evidence

ORD record
ord-4cd07bbed21e40a5bdfb91c0d1f9b74d
Source dataset
uspto-grants-1987_11
Patent number
US04704459

Reaction notes

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