- Selective one-pot synthesis of aminopolyhalobenzonitriles from polyhalobenzotrichlorides in anhydrous ammonia
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Polyhalogenated benzotrichlorides (pentafluoro-, chlorotetrafluoro-, chlorotrifluoro-, and tetrafluorobenzotrichlorides) undergo one-pot ammonolysis?+?aminodefluorination by the action of anhydrous ammonia to form mono- and diamino derivatives of polyhalobenzonitriles. For the substrates comprising halogen at the para-position, the ammonolysis of the CCl3 group and the first aminodefluorination occur simultaneously in the temperature range from ?33 to 5?°C. The temperature of introducing the second NH2 group is higher by 60–100?°C, whereby conditions were found for the selective synthesis of mono- and diaminopolyhalobenzonitriles. The use of anhydrous ammonia as a reagent and a solvent minimizes side reactions and simplifies an isolation of the high purity products.
- Vaganova, Tamara A.,Rodionov, Vladimir I.,Chuikov, Igor P.,Chochrina, Ekaterina A.,Malykhin, Evgenij V.
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- Process for the preparation of polyhalogenated benzotrifluorides, benzotrichlorides and benzoyl chlorides and new trihalogenobenzotrichlorides and -benzoyl chlorides
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Polyhalogenated benzotrifluorides can be reacted with chlorides from the series of Friedel-Crafts catalysts to give the corresponding benzotrichlorides, which can be hydrolysed by water in the presence of iron(III) chloride to give the corresponding benzoyl chlorides. These are suitable as intermediate products for the preparation of active compounds for medicaments and feed additives.
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- Process for the preparation of nuclear-halogenated benzotrichlorides from the corresponding benzotrifluorides
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Nuclear-halogenated benzotrichlorides are prepared in a particularly advantageous manner from the corresponding nuclear-halogenated benzotrifluorides by reacting nuclear-halogenated benzotrifluorides with silicon tetrachloride in the presence of catalytic amounts of aluminium trichloride.
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