Sulfuric Acid → 5,6-difluoro-2,3-dihydro-1H-indole-2,3-dione
Reaction equation
[F:1][C:2]1[CH:3]=[C:4]([NH2:12])[C:5](=[CH:9][C:10]=1[F:11])[C:6]([OH:8])=O.FC1C=C(C=CC=1F)N.Cl.NO.[O:25]=[CH:26]C(Cl)(Cl)Cl.S(=O)(=O)(O)O>>[F:11][C:10]1[CH:9]=[C:5]2[C:4](=[CH:3][C:2]=1[F:1])[NH:12][C:26](=[O:25])[C:6]2=[O:8]Participants
6
Procedure
U.S. Pat. No. 4,833,270 also relates to the synthesis of 4,5-difluoroanthranilic acid by, first, reacting 3,4-difluoroaniline with hydroxylamine hydrochloride in the presence of chloral. The resulting intermediate is then cyclyzed using sulfuric acid to form 5,6-difluoroisatin. The 4,5-difluoroanthranilic acid is produced by oxidation of the aforementioned isatin with hydrogen peroxide. As before, however, 3,4-difluoroaniline is expensive and difficult to obtain.
Sources & evidence
- ORD record
- ord-efd6dbeb92044017afd17dbe31de8ec6
- Source dataset
- uspto-grants-1995_07
- Patent number
- US05436368
Reaction notes
Loading…