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US 2016/0096849 A1Published application
Carbazole dioxazine pigments
OwnerKeki Hormusji GHARDAinventor
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Abstract
The present disclosure relates to a benzoyl substituted carbazole-dioxazine pigment and its preparation. The process involves benzoylation of 3-nitro-N-ethylcarbazole in monochlorobenzene using benzoylchloride and ferric chloride to yield 3-nitro-6-benzoyl-N-ethyl carbazole, which on catalytic hydrogenation and subsequent condensation with chloranil and cyclisation yields benzoyl substituted carbazole-dioxazine pigment.
Claims11
A process for the synthesis of a carbazole-dioxazine pigment of Formula I;
- wherein,
- R is C1-C8 alkyl group, preferably R is an ethyl group,
- R1 is a chloro group, and
- R2 is a benzoyl group,
- said process comprising the following steps:
- a) reacting 3-nitro-N-ethylcarbazole with benzoylchloride in the presence of monochlorobenzene and ferric chloride to obtain 3-nitro-6-benzoyl-9N-ethyl carbazole;
- b) hydrogenating said 3-nitro-6-benzoyl-N-ethyl carbazole in the presence of a catalyst and a promoter in a solvent to obtain 6-benzoyl-3-amino-N-ethyl carbazole;
- c) condensing 6-benzoyl-3-amino-N-ethyl carbazole with chloranil in the presence of a solvent and sodium acetate to obtain an intermediate of formula II;
- and
- wherein, R is C1-C8 alkyl group, preferably R is an ethyl group,
- R1 is a chloro group, and
- R2 is a benzoyl group,
- d) cyclizing the intermediate using a cyclizing agent to obtain carbazole-dioxazine pigment of formula I.
10 more elements
A carbazole-dioxazine pigment of formula I;
- wherein,
- R is C1-C8 alkyl group, preferably R is an ethyl group,
- R1 is a chloro group;
- and
- R2 is a benzoyl group;
2 more elements
Dependencies are inferred from the claim text.