Process for preparing a novel crystalline form of iodosulfuron-methyl-sodium and use of the same

Patent metadata

Field	Value
Publication number	US-10059676-B2
Application number	US-201514926133-A
Country	US
Kind code	B2
Filing date	Oct 29, 2015
Priority date	Oct 29, 2015
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

A crystalline form of iodosulfuron-methyl-sodium of formula (I), the crystal preparation process, the analyses of the crystal through various analytical methods and using the crystal to prepare stable agrochemical formulation. The invention also describes the use of various solvents towards the crystalline form preparation conditions.

First claim

The invention claimed is:

1. A crystalline modification I of iodosulfuron-methyl-sodium obtained by (i) dissolving amorphous iodosulfuron-methyl-sodium in a solvent to obtain a solution, wherein the solvent is methanol, ethanol, or a mixture thereof, (ii) mixing the solution at room temperature to obtain a solid precipitate, (iii) cooling the solution including the solid precipitate, (iv) centrifuging the cooled solution to obtain filtered crystals, (v) washing the filtered crystals with the alcohol, and (vi) drying the washed crystals under vacuum,
wherein the obtained crystalline modification I of iodosulfuron-methyl-sodium exhibiting each of the following reflexes in an X-ray powder diffractogram recorded using Cu—Kα radiation at 25° C.:
2θ=11.558±0.2   (1)

2θ=14.569±0.2   (2)

2θ=18.045±0.2   (3)

2θ=19.442±0.2   (4)

2θ=20.633±0.2   (5)

2θ=23.226±0.2   (6)

2θ=26.145±0.2   (7)

2θ=27.199±0.2   (8)

2θ=27.877±0.2   (9)

2θ=29.090±0.2   (10).

2. The crystalline modification I of iodosulfuron-methyl-sodium according to claim 1 , exhibiting IR spectrum with the characteristic bands at 3516.78, 3330.55, 2946.18 and 2160.93 cm −1 .

3. A composition comprising the crystalline modification I of iodosulfuron-methyl-sodium according to claim 1 and at least one herbicidally acceptable auxiliary.

4. The composition according to claim 3 , wherein the composition is in the form of a suspension concentrates (SC), an oil-based suspension concentrates (OD), water-soluble granules (SG), a dispersible concentrate (DC), an emulsifiable concentrates (EC), an emulsion seed dressing, a suspension seed dressing, granules (GR), microgranules (MG), a suspoemulsion (SE) or water-dispersible granules (WG).

5. The composition according to claim 4 , wherein the composition is in the form of an oil-based suspension concentrate (OD).

6. The composition according to claim 4 , wherein the composition is in the form of water-dispersible granules (WG).

7. The composition according to claim 4 , wherein the composition is in the form of water-soluble granules (SG).

8. The composition according to claim 3 , wherein the auxiliary is selected from one or more of a diluent, a wetting agent, a dispersant, and a thickening agent.

9. The composition according to claim 3 , which comprises crystalline modification I of iodosulfuron-methyl-sodium in an amount of less than 75% by weight.

10. A method of controlling unwanted plant growth comprising applying to a plant, plant part, or locus thereof a herbicidally effective amount of crystalline modification I of iodosulfuron-methyl-sodium according to claim 1 .

Assignees

• Rotam Agrochem Int Co Ltd

Inventors

• Bristow James Timothy

Classifications

• A01N25/12

  Powders or granules (A01N25/26 takes precedence) · CPC title

• A01N47/36

  containing the group >N—CO—N< directly attached to at least one heterocyclic ring; Thio analogues thereof · CPC title

• C07D251/42 Primary

  One nitrogen atom · CPC title

• C07D251/16

  to only one ring carbon atom · CPC title

• C07C311/57 Primary

  having sulfur atoms of the sulfonylurea groups bound to carbon atoms of six-membered aromatic rings · CPC title