Process for preparing 2,2'-dichloro-hydrazobenzene

A technology of dichlorohydroazo and o-nitrochlorobenzene, which is applied in 2 fields, can solve the problems of catalyst separation and recovery and regeneration yield affecting production costs, precious metal catalysts are expensive, and labor-intensive, etc., to achieve recovery and mechanical application Convenience, low cost, and production cost reduction effects
CN1594286AInactive Publication Date: 2005-03-16JIANGSU YANGNONG CHEM GROUP
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
JIANGSU YANGNONG CHEM GROUP
Publication Date
2005-03-16
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a process for preparing 2,2'-dichloro-hydrazobenzene by using ortho-nitrochlorobenzene as raw material, nickel system as catalyst, mixed solvent of alcohols and aromatic hydrocarbons as reaction medium for reaction under alkaline condition. The method can be used not only for intermittent hydrogenation reduction, but also for continuous hydrogenation preparation of 2, 2'-dichloro-hydrazobenzene.
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Description

technical field

[0001] The invention relates to a preparation method in the technical field of fine chemical products, in particular to a preparation method of 2,2'-dichlorohydroazobenzene. Background technique

[0002] 2,2'-dichlorohydroazobenzene is an intermediate for the production of 3,3'-dichlorobenzidine, and 3,3'-dichlorobenzidine is a very important pigment intermediate. Currently, 3 , The methods of 3'-dichlorobenzidine (DCB) mainly include zinc powder method, formaldehyde-hydrazine hydrate method and catalytic hydrogenation method. Among them, the zinc powder method and the formaldehyde-hydrazine hydrate method are the main methods for producing 3,3'-dichlorobenzidine in my country. U.S. Patent 3,156,724, European Patent 0,391,606, introduced the use of noble metal catalysts such as Pd / c, Pt / c, etc. and 1,4-naphthoquinone, 2,3-dichloro-1,4-naphthoquinone or 2-hydroxy anthraquinone or 2,6-Hydroxyanthraquinone is used as a cocatalyst, and an appropriate amount of ...

Claims

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