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1. (WO2014199400) CARBAZOLE DIOXAZINE PIGMENT AND A METHOD FOR ITS PREPARATION

Pub. No.:    WO/2014/199400    International Application No.:    PCT/IN2014/000388
Publication Date: Fri Dec 19 00:59:59 CET 2014 International Filing Date: Thu Jun 12 01:59:59 CEST 2014
IPC: C09B 5/26
C09B 5/60
C07D 498/22
C07D 498/04
Applicants: GHARDA, Keki Hormusji
Inventors: GHARDA, Keki Hormusji
Title: CARBAZOLE DIOXAZINE PIGMENT AND A METHOD FOR ITS PREPARATION
Abstract:
The present disclosure provides 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 -NHC(=O)Ph group. The pigment is synthesized from 3-nitro-N-ethylcarbazole. The first step is nitration of 3-nitro-N-ethylcarbazole to form 3,6-dinitro-N-ethylcarbazole which is reduced to form 3-amino-6-nitro-N-ethylcarbazole. This amino compound is benzoylated to form 3-benzamido-6-nitro-N-ethylcarbazole which is then hydrogenated to form 6-amino-3-benzamido-N-ethylcarbazole. Condensation of 6-amino-3-benzamido-N-ethylcarbazole with chlroanil provides an intermediate. Cyclization of the intermediate in the presence of a cyclization reagent provides the compound of Formula-I. The pigment has wavelength of maximum absorption (λmax) at 571nm in dimethylformamide as a solvent.