US 11,021,428 B2 · Method for producing cis,cis-1,2,4-cyclohexane tricarboxylic acid crystal

Abstract

An object of the present invention is to provide a method for producing cis,cis-1,2,4-cyclohexanetricarboxylic acid crystals, from which high purity cis,cis-1,2,4-cyclohexanetricarboxylic acid crystals are obtained. The method for producing cis,cis-1,2,4-cyclohexanetricarboxylic acid crystals of the present invention comprises the following steps: Step 1: measuring a mass ratio (cis/trans ratio) of cis,cis-1,2,4-cyclohexanetricarboxylic acid to trans,trans-1,2,4-cyclohexanetricarboxylic acid in an aqueous starting material solution comprising the cis,cis-1,2,4-cyclohexanetricarboxylic acid to give an aqueous starting material solution for crystal precipitation having a cis/trans ratio of 10 or more; and Step 2: subjecting the aqueous starting material solution for crystal precipitation obtained in step 1 to crystal precipitation.

Claims20

Dependent claims

A method for producing one or more cis,cis-1,2,4-cyclohexanetricarboxylic acid crystals, the method comprising:

selecting and/or adjusting a cis/trans mass ratio of cis,cis-1,2,4-cyclohexanetricarboxylic acid to trans,trans-1,2,4-cyclohexanetricarboxylic acid in an aqueous starting material solution comprising the cis,cis-1,2,4-cyclohexanetricarboxylic acid to obtain a selected aqueous starting material solution for crystal precipitation having a cis/trans ratio of 19.7 or more;
and
subjecting the selected aqueous starting material solution to crystal precipitation, to obtain resulting cis,cis-1,2,4-cyclohexanetricarboxylic acid crystals having a purity of 98.8% by mass or more.

Dependencies are inferred from the claim text.

Facts

Application

16/496,593Filed 19 Mar 2018

Priority

JP JP2017-06591829 Mar 2017

Published

US 2020/0317596 A18 Oct 2020

Granted

1 Jun 2021

Term ends

Not estimatedThe source records don’t support an estimate.

Classification6 codes

C07C 51/43
Separation; Purification; Stabilisation; Use of additives: by change of the physical state, e.g. crystallisation
C07B 2200/13
Indexing scheme relating to specific properties of organic compounds: crystalline forms, e.g. polymorphs
C07C 61/08
Compounds having carboxyl groups bound to carbon atoms of rings other than six-membered aromatic rings: saturated compounds having a carboxyl…
C07C 2601/14
With a six-membered ring: the ring being saturated

Method for producing cis,cis-1,2,4-cyclohexane tricarboxylic acid crystal

Life of this patent

Method for producing cis,cis-1,2,4-cyclohexane tricarboxylic acid crystal

Life of this patent

Abstract

Claims20