Crystalline hydrate of topramezone sodium salt and preparation method therefor

Patent metadata

Field	Value
Publication number	US-12365671-B2
Application number	US-202117175112-A
Country	US
Kind code	B2
Filing date	Feb 12, 2021
Priority date	Feb 12, 2021
Publication date	Jul 22, 2025
Grant date	Jul 22, 2025

Abstract

A crystalline hydrate of topramezone sodium salt is provided. A preparation method for the crystalline hydrate of topramezone sodium salt and herbicidal compositions including the crystalline hydrate of topramezone sodium salt are also provided.

First claim

The invention claimed is:

1. A crystalline 2.5 hydrate of topramezone sodium salt of formula I:

2. The crystalline hydrate of claim 1 wherein said crystalline hydrate is orthorhombic and has the following parameters:

Parameters
Values

Space group
Pbcn

a
2563.60(15)
pm

b
953.24(7)
pm

c
1566.96(10)
pm

α
90°

β
90°

γ
 90°.

3. An herbicidal composition comprising the crystalline hydrate of claim 1 and fillers and/or surfactants.

4. The herbicidal composition of claim 3 wherein the composition is in the form of a soluble granule (SG), a water dispersible granule (WG), a wettable powder (WP), an oil dispersion (OD) or a dispersible tablet.

5. A method for preparing the crystalline hydrate of claim 1 comprising the following steps:
1) forming topramezone sodium salt aqueous solution by mixing from 1:0.9 to 1:1.2 stoichiometric ratio of topramezone and sodium hydroxide; and
2) crystallizing the crystalline hydrate by maintaining the temperature of the resulting solution of step 1) at from −15° C. to 15° C.

6. The method of claim 5 wherein:
at step 1): topramezone and water are added to a reaction apparatus and sodium hydroxide is added to the solution at a stoichiometric ratio of from 1:0.9 to 1:1.2 of topramezone to sodium hydroxide, the solution mixture is stirred at from 20° C. to 60° C. to form the topramezone sodium salt aqueous solution; and
at step 2): the resulting solution of step 1) is cooled to ambient temperature and subsequently cooled to −15° C. to 15° C. in ice-salt bath, the solution is stirred until crystallization is stopped, and the resulting slurry is filtered and dried to obtain the crystalline hydrate.

7. The method of claim 5 , wherein:
at step 1): the stoichiometric ratio of topramezone to sodium hydroxide is from 1:1 to 1:1.1.

8. The method of claim 5 wherein:
at step 1): the weight ratio of topramezone to water is from 1:3 to 1:8.

9. The method of claim 5 wherein:
at the end of step 1) 50% to 80% of the water of the topramezone sodium salt aqueous solution is removed by rotary evaporation, one or more polar solvent is added to the solution and optionally heated to form a clear solution.

10. The method of claim 9 wherein:
at step 1): the weight ratio of topramezone to water is from 1:4 to 1:8.

11. The method of claim 9 wherein the one or more polar solvent is selected from methanol, ethanol, isopropanol, n-butanol, tert-butanol, and/or mixtures thereof.

12. A method for the control of plant growth, the method comprising applying an herbicidal composition including the crystalline hydrate of claim 1 to at least one plant or the locus thereof.

13. The method of claim 12 , wherein the at least one plant is a gramineous weed or broadleaf weed in a maize field.

14. The method of claim 12 , wherein the at least one plant is fern, barnyard grass, steak grass, wild Paris, dog-tail herb, chenopodium quinoa, polygonum capitatum, cimicifugae , purslane, cocklebur, or black nightshade in a maize field.

Assignees

• Rotam Agrochem Int Co Ltd
• Albaugh Llc

Inventors

• Bristow James Timothy

Classifications

• A01N25/30

  characterised by the surfactants · CPC title

• A01N25/04

  Dispersions, {emulsions, suspoemulsions, suspension concentrates} or gels (foams A01N25/16) · CPC title

• A01N25/14

  wettable · CPC title

• C07B2200/13

  Crystalline forms, e.g. polymorphs · CPC title

• A01N43/80

  five-membered rings with one nitrogen atom and either one oxygen atom or one sulfur atom in positions 1,2 · CPC title