application and preparation of 5-aminoisophthalic acid_kain industrial additive

background and overview^[1][2]

5-amino-isophthalic acid is a widely used fine chemical product. it is insoluble in water and soluble in methanol, ethanol and acetone. it is mainly used as a pharmaceutical intermediate and can be used to prepare 5-hydroxypropionylamino-2 , 4,6-triiodoisopeptide acid-bis(1,3-dihydroxyisopropylamide) and other nonionic iodinated x-ray contrast agents, which have good water solubility, low osmotic pressure, and are easy to use. it has low chemical toxicity and side effects and a wide range of uses. it has good market potential internationally.

preparation^[1]

method 1,

(1) after ultrasonic pretreatment with acetone, ethanol and distilled water, nickel foam with a pore diameter of 0.2mm, a pore density of 110ppi, and a porosity of ≥95% is dried in a vacuum, placed in a tube furnace, and placed in an argon atmosphere. the temperature was raised to 600°c at 5°c, and acetylene gas was introduced to react for 1 hour. after the reaction was completed, the temperature was lowered to room temperature in an argon atmosphere to obtain a nickel foam/carbon nanotube magnetic catalyst. among them, the nickel foam/carbon nanotube magnetic catalyst was the content of medium carbon nanotubes is 0.5wt%.

(2) 5-nitro-isotitanic acid is fully dissolved in water, transferred to the reaction kettle, ammonia is added to adjust the ph of the system to 9, hydrogen gas is introduced at a flow rate of 25ml/min, and nickel foam/carbon nanotubes are added magnetic catalyst, react at a constant temperature of 90°c for 100 minutes to obtain a 5-amino-isophthalic acid solution.

(3) after recovering the 5-amino-isophthalic acid solution using a magnet catalyst, filter and recover the mother liquor, add hydrochloric acid to acidify, lower to room temperature, recrystallize, and dry to obtain 5-amino-isophthalic acid.

method 2,

(1) add 400g of water and 60g of sodium carbonate to a 1000ml three-necked flask, start stirring, heat to dissolve, then add 100g of 5-nitroisophthalic acid (i) to completely dissolve;

(2) under stirring, add the pre-prepared 20% sodium disulfide aqueous solution dropwise to the solution obtained in (1), control the temperature to 90-98°c, complete the addition in about half an hour, and reflux for 2.5 hours. hot filter and collect the filtrate, in which the ratio of 5-nitroisophthalic acid to sodium disulfide is 1:0.6;

(3) add concentrated hydrochloric acid to the filtrate obtained in (2) to acidify the ph to 3~3.5, cool and filter, then wash with cold water and dry to obtain 83.2g of 5-aminoisophthalic acid (ii) , yield 97%, purity 99.5%, melting point >300°c.

apply^[3]

the complexes formed by the transition metal ni, 5-aminoisophthalic acid and 4, 4’-bipyridine have rich and diverse structures, which are of great research significance for the design and synthesis of complexes with target structures. cn201811303808.1 discloses a 5-aminoisophthalate nickel complex and a preparation method. the nickel 5-aminoisophthalate complex belongs to the monoclinic crystal system with a space group of 2/c. in this complex, the amino and carboxyl groups on 5-aminoisophthalic acid coordinate with the metal ion co(ii) ions in the form of monodentate or bidentate chelates, and 4,4′-bipyridine forms a bidentate bridge. it is coordinated with the metal ion cd(ii) ion in the form of a link, and the multidentate bridge of 5-aminoisophthalic acid and 4,4′-bipyridine with the central co(ii) ion constitutes the complex. three-dimensional network space structure. the present invention uses 5-aminoisophthalic acid and 4,4′-bipyridyl as ligands and nickel sulfate hexahydrate to obtain a nickel complex through a hydrothermal method. it has the advantages of simple process, low cost, good repeatability, etc., and is a synthetic method. transition metal complexes provide a certain basis.

main reference materials

[1] [chinese invention] cn201711246069.2 a production method of high-purity, efficient and high-yield 5-amino-isophthalic acid

[2] cn200810020399.4 method for preparing 5-aminoisophthalic acid from 5-nitroisophthalic acid

[3] cn201811303808.15-nickel aminoisophthalate complex and preparation method