Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Synthesis of Electrophotographically Active Chlorodiane Blue Pigment

IP.com Disclosure Number: IPCOM000047405D
Original Publication Date: 1983-Nov-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Cort, LF: AUTHOR [+3]

Abstract

The novelty in this synthetic procedure is found in the interactions of certain process variables: (1) rate of addition of the reagents used to form chlorodiane blue (CDB), (2) the ratios of pyrridine-dimethylsulfoxide-dimethylformamide, (3) the reaction temperature, and (4) the isolation and purification techniques used to obtain the final product. Preparation of bis-diazo-3,3'-dichlorobenzidine bis-tetrafluoroborate is accomplished by treating an aqueous 6M HCl solution of 3,3'-dichlorobenzidine with two equivalents of nitrous acid. A fourfold excess of fluoroboric acid is then added to the cold acid solution to precipitate bis-diazo-3,3'-dichlorobenzidine as the bis-tetrafluoroborate salt. This salt is isolated by vacuum filtration and is then washed with cold methanol and subsequently with diethyl ether.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 87% of the total text.

Page 1 of 1

Synthesis of Electrophotographically Active Chlorodiane Blue Pigment

The novelty in this synthetic procedure is found in the interactions of certain process variables: (1) rate of addition of the reagents used to form chlorodiane blue (CDB), (2) the ratios of pyrridine-dimethylsulfoxide-dimethylformamide, (3) the reaction temperature, and (4) the isolation and purification techniques used to obtain the final product. Preparation of bis-diazo-3,3'-dichlorobenzidine bis- tetrafluoroborate is accomplished by treating an aqueous 6M HCl solution of 3,3'- dichlorobenzidine with two equivalents of nitrous acid. A fourfold excess of fluoroboric acid is then added to the cold acid solution to precipitate bis-diazo- 3,3'-dichlorobenzidine as the bis-tetrafluoroborate salt. This salt is isolated by vacuum filtration and is then washed with cold methanol and subsequently with diethyl ether. The bis-diazo salt is used without further purification in a coupling reaction. One molar equivalent of the bis-diazo salt is dissolved in dimethylsulfoxide to give a 12% solution (weight/volume). This is added over a 30-minute period to two molar equivalents of naphthol AS dissolved in a 1:2.5 solution of pyrridine-dimethylformamide solution maintained at 5-12 C. The reaction mixture is then quenched by adding ice to quadruple the initial volume. After the quenched reaction mixture has been stirred for 12 hours the pigment is isolated by vacuum filtration, washed with copious amounts of...