Process for preparation of triazole compound

Patent metadata

Field	Value
Publication number	US-12441692-B2
Application number	US-202318180367-A
Country	US
Kind code	B2
Filing date	Mar 8, 2023
Priority date	Mar 9, 2022
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

Processes for preparation of a high purity cyproconazole, i.e., (2RS,3RS;2RS,3SR)-2-(4-chlorophenyl)-3-cyclopropyl-1-(1H-1,2,4-triazol-1-yl) butan-2-ol; and its compound i.e., 2-(4-chlorophenyl)-2-(1-cyclopropylethyl) oxirane generally includes reacting a ketone of formula (II) with a sulfonium salt in the presence of a base to obtain the oxirane compound of formula (III);wherein the sulfonium salt is obtained by reacting dimethyl sulfide and dimethyl sulfate in the presence of water; followed by reacting the oxirane compound of formula (III) with 1,2,4-triazole or its alkali metal salt to obtain a crude cyproconazole; and treating the crude cyproconazole with an aqueous alcohol to obtain a higher purity cyproconazole.

First claim

The invention claimed is:

1. A process for preparing high purity cyproconazole of formula (I),

the process, free of column chromatography, comprising:
a) reacting a ketone of formula (II) with a sulfonium salt in the presence of a base to obtain a compound of formula (III);

wherein the sulfonium salt is obtained by reacting dimethyl sulfide and dimethyl sulfate in the presence of water;
b) reacting the compound of formula (III) with 1,2,4-triazole or its alkali metal salt to obtain a crude cyproconazole; and
c) treating the crude cyproconazole with an aqueous alcohol to obtain the high purity cyproconazole.

2. The process as claimed in claim 1 , wherein reacting the compound of formula (III) in step b) is the alkali metal salt of 1,2,4-triazole.

3. The process as claimed in claim 1 , wherein said alkali metal salt of 1,2,4-triazole is prepared in situ, by reacting the 1,2,4-triazole with an alkali metal base.

4. The process as claimed in claim 3 , wherein said alkali metal base is selected from the group consisting of alkali metal hydroxides, carbonates and bicarbonates.

5. The process as claimed in claim 1 , wherein the aqueous alcohol comprises methanol and water, and wherein the weight ratio of water to alcohol in the aqueous alcohol is in a range from about 10:90 to about 90:10.

6. The process for preparing a compound of formula (III) of claim 1 , wherein the high purity cyproconazole has a purity greater than 98%.

7. The process as claimed in claim 6 , wherein said base is an organic base or an inorganic base.

8. The process as claimed in claim 6 , wherein said base comprises sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, or potassium bicarbonate.

9. The process as claimed in claim 6 , wherein said sulfonium salt is prepared in situ by reacting the dimethyl sulfide, dimethyl sulfate and water.

10. The process of claim 6 , wherein
reacting the ketone of formula (II) with the sulfonium salt in the presence of the base and dimethyl sulfide is at a temperature from 35° C. to 60° C.; and
wherein the sulfonium salt is obtained by reacting the dimethyl sulfide and dimethyl sulfate in the presence of water at a temperature from 20° C. to 40° C.

Assignees

• Upl Ltd

Inventors

• Desai Jignesh Amrutlal
• Panchal Digish Manubhai

Classifications

• C07D301/02

  Synthesis of the oxirane ring · CPC title

• C07D303/08

  with hydrocarbon radicals, substituted by halogen atoms, nitro radicals or nitroso radicals · CPC title

• C07B2200/13

  Crystalline forms, e.g. polymorphs · CPC title

• A01P3/00

  Fungicides · CPC title

• A01N43/653

  1,2,4-Triazoles; Hydrogenated 1,2,4-triazoles · CPC title