1-Fluoro-3,5-dimethyl-benzene → 2,4-Dichloro-1-fluoro-3,5-dimethylbenzene
Reaction equation
[Cl:1][C:2]1[C:10]([C:11]#N)=[C:9]([Cl:13])[C:8]([F:14])=[CH:7][C:3]=1[C:4](Cl)=O.ClC1C(C#N)=C2C(C(=O)C(C(O)=O)=CN2C2CC2)=CC=1F.C(C1C(F)=C(C=C(F)C=1F)C(F)=O)#N.FC1C=C(C)C=C(C)C=1>>[Cl:1][C:2]1[C:10]([CH3:11])=[C:9]([Cl:13])[C:8]([F:14])=[CH:7][C:3]=1[CH3:4]Participants
Reactant 4
Product 1
Procedure
An alternative process for the preparation of the intermediate compound 2,4-dichloro-3-cyano-5-fluoro-benzoyl chloride, which serves as a starting material for the preparation of 7-chloro-8-cyano-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid (EP-A-0 276 700) and which can converted into 3-cyano-2,4,5-trifluoro-benzoyl fluoride, starts from 5-fluoro-1,3-xylene: 5-fluoro-1,3-xylene is dichlorinated in the nucleus under ionic conditions in the presence of a catalyst to give 2,4-dichloro-5-fluoro-1,3-dimethylbenzene and this is then chlorinated under free-radical conditions in the side chains to give 2,4-dichloro-5-fluoro-3-dichloromethyl-1-trichloromethylbenzene. This is hydrolysed via 2,4-dichloro-5-fluoro-3-dichloromethylbenzoic acid to give 2,4-dichloro-5-fluoro-3-formyl-benzoic acid and then reacted to give 2,4-dichloro-5-fluoro-3-N-hydroxyiminomethyl-benzoic acid. By treatment with thionyl chloride, 2,4-dichloro-3-cyano-5-fluoro-benzoyl chloride is obtained, which can additionally be reacted by means of a chlorine/fluorine exchange to give 3-cyano-2,4,5-trifluoro-benzoyl fluoride. ##STR4##
Sources & evidence
- ORD record
- ord-6568a7250a3b43df9badb6a11e2b3251
- Source dataset
- uspto-grants-2000_10
- Patent number
- US06133260
Reaction notes
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