Supercharge Your Innovation With Domain-Expert AI Agents!

Preparation method of pamoic acid

A technology of methylenebishydroxynaphthoic acid and dimethylformamide, which is applied in the field of preparation of methylenebishydroxynaphthoic acid, can solve the problems of cumbersome preparation methods and high cost, and achieve simple preparation methods, few steps, and high yield. high rate effect

Active Publication Date: 2014-07-02
ANHUI JIXI COUNTY HUIHUANG CHEM
View PDF2 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the existing preparation methods are cumbersome and costly

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0012] A preparation method of methylene bishydroxy naphthoic acid, comprising the following steps:

[0013] (1), put 266kg N,N-dimethylformamide into the reaction kettle, drop in 2,3-acid 175kg, paraformaldehyde 21kg, heat up to 60°C, keep warm for 30 minutes, add catalyst 98% sulfuric acid, Raise the temperature to 80°C, then naturally raise the temperature to 100°C due to the heat generated by the reaction, keep it warm for 3 hours, and the reaction is complete;

[0014] (2) After the reaction in step (1), cool down to about 25°C, pump in 224 kg of methanol, centrifuge, rinse, centrifuge, and dry to obtain the final product.

[0015] This product yield is more than 85%, and the quality index of product is shown in Table 1

[0016] Table 1 Product quality indicators

[0017] project Index Exterior Yellow or brown yellow crystalline powder Purity% ≥ 98.0 Acidity PH 6～7 Loss on drying % ≤ 1.0 Melting point ℃ 288～304

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a preparation method of pamoic acid. The preparation method comprises the following steps: putting N,N-dimethylformamide in a reaction kettle, adding a 2,3-acid and a paraformaldehyde, heating to 58-62DEG C, maintaining the temperature for 28-32min, adding a catalyst and 98% sulfuric acid, heating to 75-85DEG C, naturally heating to 95-105DEG C through heat generated by above reaction, maintaining the temperature for 2.5-3.5h, cooling to about 25DEG C after reaction finishing, adding methanol through pumping, centrifuging, rinsing, centrifuging, and drying to obtain the pamoic acid. The preparation method which adopts the 2,3-acid as the raw material has the advantages of safety, environmental pollution, simplicity, less step, and high yield.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a preparation method of methylene bishydroxy naphthoic acid. Background technique [0002] Methylenebishydroxynaphthoic acid is an important intermediate, which is mainly used to synthesize food additives, prevent and treat Alzheimer's disease, diabetes, and antimalarial drugs, and is widely used in the synthesis of medicines and pesticides. However, the existing preparation methods are cumbersome and costly. Contents of the invention [0003] The purpose of this invention is to provide a kind of reaction method simple, the preparation method of the methylene dihydroxynaphthoic acid of reliable operation. [0004] The above purpose is achieved through the following schemes: [0005] A kind of preparation method of methylene dihydroxynaphthoic acid is characterized in that: [0006] Include the following steps: [0007] (1) Put N,N-dimethylformamide into the reactor, put in ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C07C65/24C07C51/367
Inventor 程捷程明光
Owner ANHUI JIXI COUNTY HUIHUANG CHEM
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com