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US 5,554,774 AGranted
Preparation of chlorinated violanthrones or isoviolanthrones
AssigneeBASF SE
InventorsUdo Bergmann, Gerhard Sch afer, Heinrich Kowarsch
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Abstract
Chlorinated violanthrones or isoviolanthrones are prepared by reacting violanthrone or isoviolanthrone with chlorine in the presence of a diluent, using aliphatic carboxylic acids and/or aliphatic halo carboxylic acids as diluent for this purpose.
Claims7
A process for preparing chlorinated violanthrones or isoviolanthrones, comprising:
- preparing a liquid reaction medium of a violanthrone or a isoviolanthrone in a diluent of a C.sub.2 -C.sub.5 aliphatic monocarboxylic acid, a C.sub.2 -C.sub.5 aliphatic halomonocarboxylic acid, or combination thereof;
- heating the reaction medium to the required temperature for chlorination which is within the range of 40.degree.-160.degree. C.;
- and
- introducing chlorine into the heated reaction medium thereby selectively chlorinating the violanthrone or isoviolanthrone starting material.
1 more element
Dependencies are inferred from the claim text.