CN101643429A - Method for preparing 3,3'-dichlorobenzidine hydrochloride through formaldehyde-hydrazine hydrate reduction - Google Patents
Method for preparing 3,3'-dichlorobenzidine hydrochloride through formaldehyde-hydrazine hydrate reduction Download PDFInfo
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- CN101643429A CN101643429A CN200810139126A CN200810139126A CN101643429A CN 101643429 A CN101643429 A CN 101643429A CN 200810139126 A CN200810139126 A CN 200810139126A CN 200810139126 A CN200810139126 A CN 200810139126A CN 101643429 A CN101643429 A CN 101643429A
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Abstract
The invention discloses a method for preparing 3,3'-dichlorobenzidine hydrochloride through formaldehyde-hydrazine hydrate reduction. In an alkaline medium and in the presence of a metal catalyst, formaldehyde-hydrazine hydrate catalytic reduction is performed, and then 3,3'-dichlorobenzidine hydrochloride is collected from reaction products by a conventional method. The molar yield of finished products can be up to over 90 percent. The method has the advantages of reasonable process route, high yield and purity of the finished products prepared by the method, thereby having great industrialization prospects.
Description
Technical field
The present invention relates to a kind of formaldehyde-hydrazine hydrate reduction preparation 3, the method for 3 '-dimethoxy benzidine hydrochloride
Background technology
3,3 '-dimethoxy benzidine hydrochloride is a kind of important pigment, dyestuff intermediate, current preparation 3, and 3 '-dimethoxy benzidine hydrochloride generally carries out translocation reaction by sulfuric acid or hydrochloric acid and forms.But sometimes in translocation reaction, exist processing step not too rationally, the inaccurate problem of processing parameter, cause that prepared product yield is not high, cost is bigger, and raw material can not be fully utilized.
Summary of the invention
For solving the problem of above existence, the invention provides a kind of 3, the preparation method of 3 '-dimethoxy benzidine hydrochloride, its technical scheme of taking is:
3,3 '-dimethoxy benzidine hydrochloride is prepared from by following steps:
1) add o-Nitrophenyl methyl ether, 10～30% sodium hydroxide solutions and catalyzer in the stainless steel still, temperature is controlled at 30～80 ℃, reacts 9～10 hours, generates zinin, filter, and the filtrate layering, oil phase is 2,2 '-dimethoxy zinin;
2) in the stainless steel still, add 2,2 '-dimethoxy zinin, emulsifying agent, promotor, catalyzer and 5～20% sodium hydroxide solutions, 30～80 ℃ of controlled temperature, reacted 9～10 hours, generate hydrogenation nitrogen idol benzene, filter solid-liquid separation, granular 2,2 '-dimethoxy hydrazobenzene;
3) the beginning acid of preparation about 40%, add 2 then, 0～40 ℃ of insulation reaction of 2 '-dimethoxy hydrazobenzene 6 hours, get 3,3 '-dimethoxy benzidine vitriol crude product filters the rear filtrate layering, and dimethylbenzene repeats to apply mechanically, after the making beating of filter cake water, being neutralized to pH value with sodium hydroxide solution again is 7～9, filters then, and filter cake is added 5% hydrochloric acid soln, be heated to 85～95 ℃ complete molten, dripped 31% hydrochloric acid soln 860ml acid out then 4 hours, acid out finishes, and is cooled to 20～30 ℃, filter and promptly get 3,3 '-dimethoxy benzidine hydrochloride.
Embodiment
Below in conjunction with embodiment the present invention is elaborated:
1) in the stainless steel still, adds o-Nitrophenyl methyl ether 300kg, 10～30% sodium hydroxide solution 2500L, 1,4-naphthoquinones 2kg, temperature is controlled at 30～80 ℃, drip about formaldehyde 600kg, react 9～10 hours, generate zinin to terminal point, filter, the filtrate layering, oil phase is 2,2 '-dimethoxy zinin;
2) in the stainless steel still, add 2,2 '-dimethoxy zinin, emulsifying agent 15kg, 1,4-naphthoquinones 2kg, Raney Ni 3kg and 5～20% sodium hydroxide solution 3000L, 30～80 ℃ of controlled temperature drip about hydrazine hydrate 560kg, reacted 9～10 hours, generate hydrogenation nitrogen idol benzene, filter solid-liquid separation, granular 2,2 '-dimethoxy hydrazobenzene;
3) in still, add 40% left and right sides dilute sulphuric acid 3600L, add 2 then, 0～40 ℃ of insulation reaction of 2 '-dimethoxy hydrazobenzene 6 hours, get 3,3 '-dimethoxy benzidine vitriol crude product filters the rear filtrate layering, and dimethylbenzene repeats to apply mechanically, after the making beating of filter cake water, being neutralized to pH value with sodium hydroxide solution again is 7～9, filters then, and filter cake is added 5% hydrochloric acid soln, be heated to 85～95 ℃ complete molten, dripped 31% hydrochloric acid soln 860L acid out then 4 hours, acid out finishes, and is cooled to 20～30 ℃, filter and promptly get 3,3 '-dimethoxy benzidine hydrochloride.
Claims (4)
1, a kind of formaldehyde-hydrazine hydrate reduction legal system is equipped with 3, and the method for 3 '-dimethoxy benzidine hydrochloride is characterized in that being prepared from by following steps:
1) add o-Nitrophenyl methyl ether, 10～30% sodium hydroxide solutions and catalyzer in the stainless steel still, temperature is controlled at 30～80 ℃, reacts 9～10 hours, generates zinin, filter, and the filtrate layering, oil phase is 2,2 '-dimethoxy zinin;
2) in the stainless steel still, add 2,2 '-dimethoxy zinin, emulsifying agent, promotor, catalyzer and 5～20% sodium hydroxide solutions, 30～80 ℃ of controlled temperature, reacted 9～10 hours, generate hydrogenation nitrogen idol benzene, filter solid-liquid separation, granular 2,2 '-dimethoxy hydrazobenzene;
3) 93% sulfuric acid and water are made into beginning acid about 40%, add 2 then, 0～40 ℃ of insulation reaction of 2 '-dimethoxy hydrazobenzene 6 hours, get 3,3 '-dimethoxy benzidine vitriol crude product filters the rear filtrate layering, and dimethylbenzene repeats to apply mechanically, after the making beating of filter cake water, being neutralized to pH value with sodium hydroxide solution again is 7～9, filters then, and filter cake is added 5% hydrochloric acid soln, be heated to 85～95 ℃ complete molten, dripped 31% hydrochloric acid soln 860ml acid out then 4 hours, acid out finishes, and is cooled to 20～30 ℃, filter and promptly get 3,3 '-dimethoxy benzidine hydrochloride.
2, according to claim 1: formaldehyde-hydrazine hydrate reduction preparation 3, the method for 3 '-dimethoxy benzidine hydrochloride is characterized in that: promotor is 1, the 4-naphthoquinones.
3, according to the described formaldehyde of claim 1-hydrazine hydrate reduction preparation 3, the method for 3 '-dimethoxy benzidine hydrochloride is characterized in that: described catalyzer is a Raney Ni.
4, according to the described formaldehyde of claim 1-hydrazine hydrate reduction preparation 3, the method for 3 '-dimethoxy benzidine hydrochloride is characterized in that: reduction reaction temperature is 30～80 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200810139126A CN101643429A (en) | 2008-08-08 | 2008-08-08 | Method for preparing 3,3'-dichlorobenzidine hydrochloride through formaldehyde-hydrazine hydrate reduction |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200810139126A CN101643429A (en) | 2008-08-08 | 2008-08-08 | Method for preparing 3,3'-dichlorobenzidine hydrochloride through formaldehyde-hydrazine hydrate reduction |
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| Publication Number | Publication Date |
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| CN101643429A true CN101643429A (en) | 2010-02-10 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN200810139126A Pending CN101643429A (en) | 2008-08-08 | 2008-08-08 | Method for preparing 3,3'-dichlorobenzidine hydrochloride through formaldehyde-hydrazine hydrate reduction |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102267927A (en) * | 2011-06-15 | 2011-12-07 | 浙江大学 | Preparation method for 1-oxide-diphenyldiazene and its derivative |
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2008
- 2008-08-08 CN CN200810139126A patent/CN101643429A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102267927A (en) * | 2011-06-15 | 2011-12-07 | 浙江大学 | Preparation method for 1-oxide-diphenyldiazene and its derivative |
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Open date: 20100210 |