Sulfuric Acid → 7-Chloro-6-fluoro-1-(2,4-difluoro-5-nitrophenyl)-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid

Reaction equation

S(=O)(=O)(O)O.[Cl:6][C:7]1[N:16]=[C:15]2[C:10]([C:11](=[O:28])[C:12]([C:25]([OH:27])=[O:26])=[CH:13][N:14]2[C:17]2[CH:22]=[CH:21][C:20]([F:23])=[CH:19][C:18]=2[F:24])=[CH:9][C:8]=1[F:29].[N+:30]([O-])([O-:32])=[O:31].[K+]>>[Cl:6][C:7]1[N:16]=[C:15]2[C:10]([C:11](=[O:28])[C:12]([C:25]([OH:27])=[O:26])=[CH:13][N:14]2[C:17]2[CH:22]=[C:21]([N+:30]([O-:32])=[O:31])[C:20]([F:23])=[CH:19][C:18]=2[F:24])=[CH:9][C:8]=1[F:29]

Participants

Reactant 3

HCID 1118Sulfuric Acid

HCID 24434Potassium Nitrate

HCID 105460847-Chloro-1-(2,4-difluorophenyl)-6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid

Product 1

HCID 158603627-Chloro-6-fluoro-1-(2,4-difluoro-5-nitrophenyl)-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acidYield 94.7%

Procedure

To 25 ml of conc. sulfuric acid was added 6.0 grams of 7-chloro-1-(2,4-difluorophenyl)-6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid. With ice cooling and stirring, to the solution was added 5.0 g of potassium nitrate in portions. The temperature was slowly elevated to 80° C. at which stirring was continued for 2 hours. The reaction solution was allowed to cool, poured into 200 g of ice water, and allowed to stand overnight. The precipitate was collected by filtration, washed with distilled water, ethanol and diisopropyl ether, and air dried, to give 6.4 g of the title compound.