Title:
METHOD FOR PREPARING 4,6-DIAMINO RESORCINOL HYDROCHLORIDE
Document Type and Number:
WIPO Patent Application WO/2020/093657
Kind Code:
A1
Abstract:
Disclosed is a method for preparing 4,6-diamino resorcinol hydrochloride, which belongs to the organic chemical synthesis field. The method comprises: using a Bronsted acid and acetic anhydride as a new dioxime Beckmann rearrangement reaction system, subjecting same to an increased-temperature reaction and reduced pressure distillation so as to obtain residues and recover the solvent; subjecting the residues to warming and a reflux reaction with concentrated hydrochloric acid and SnCl2, to achieve an operation of hydrolysis; and further subjecting same to cooling, stirring and crystallization, suction filtration, hydrochloric acid washing and vacuum drying to prepare the 4,6-diamino resorcinol hydrochloride. The method has simple process steps, and uses readily available Bronsted acid and acetic anhydride; and the excess Bronsted acid and acetic anhydride in the reaction and the acetic acid produced during the reaction are recycled by reduced pressure distillation, thereby achieving reutilization, while avoiding the production of large amounts of phosphorus-containing waste water causing environmental pollution, and more effectively reducing the production cost thereof.
Inventors:
ZHA JIALONG (CN)
DING GANG (CN)
HE ZIQUAN (CN)
HU ZHIPENG (CN)
LEI HUANGSHU (CN)
GUO PENG (CN)
LI XUN (CN)
LUAN JIAKUN (CN)
DING GANG (CN)
HE ZIQUAN (CN)
HU ZHIPENG (CN)
LEI HUANGSHU (CN)
GUO PENG (CN)
LI XUN (CN)
LUAN JIAKUN (CN)
Application Number:
PCT/CN2019/083082
Publication Date:
May 14, 2020
Filing Date:
April 17, 2019
Export Citation:
Assignee:
ASTATECH CHENGDU BIOPHARMACEUTICAL CORP (CN)
International Classes:
C07C213/02; C07C215/80
Foreign References:
| US5892118A | 1999-04-06 | |||
| CN108191678A | 2018-06-22 |
Other References:
QIU,DAOJI ET AL.: "Study on Beckmann Rearrangement Reaction of Diphenyl -Methanone Oxime", JOURNAL OF NANJING NORMAL UNIVERSITY (NATURAL SCIENCE EDITION), vol. 29, no. 3, 30 September 2006 (2006-09-30), pages 50 - 52
CHEN ET AL: "Catalytic Preparation of 4,6-Diaminoresorcinol Hydrochloride with Concentrated Sulfuric Acid", NEW CHEMICAL MATERIALS, vol. 43, no. 4, 30 April 2015 (2015-04-30), pages 43 - 45, 48
CHEN ET AL: "Catalytic Preparation of 4,6-Diaminoresorcinol Hydrochloride with Concentrated Sulfuric Acid", NEW CHEMICAL MATERIALS, vol. 43, no. 4, 30 April 2015 (2015-04-30), pages 43 - 45, 48
Attorney, Agent or Firm:
CHENGDU INNOVATION-ENGINE INTELLECTUAL PROPERTY AGENT CO., LTD. (CN)
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