Process for producing isothiazole derivative
A process for producing 3,4-dichloro-5-cyanoisothiazole represented by a general formula (3): the process comprising: reacting a nitrile compound represented by a general formula (1): (wherein “n” denotes an integer of 0 to 2), with sulfur chloride represented by a general formula (2): S m Cl 2 (2) (wherein “m” represents an integer of 1 to 2), or a mixture thereof in an aprotic polar solvent. There is provided a process for producing 3,4-dichloro-5-cyanoisothiazole, which is capable of suppressing by-production of a waste, without using a raw material having a strong toxicity; and is capable of providing a product having a higher purity in a high yield and efficiency in an industrial scale, in a simple manner.
1. A process for producing 3,4-dichloro-5-cyanoisothiazole represented by formula (3):
the process comprising:
reacting a nitrile compound represented by formula (1):
(wherein “n” denotes an integer of 0 to 2), or a mixture thereof, with sulfur chloride represented by formula (2):
S m Cl 2 (2)
(wherein “m” represents an integer of 1 to 2), or a mixture thereof, in an aprotic polar solvent.
2. A process for producing 3,4-dichloro-5-cyanoisothiazole according to claim 1 , wherein the nitrile compound is a nitrile compound of formula (1) wherein “n” is 0.
3. A process for producing 3,4-dichloro-5-cyanoisothiazole according to claim 1 , wherein the nitrile compound is a nitrile compound represented by formula (1) wherein “n” is 1.
4. A process for producing 3,4-dichloro-5-cyanoisothiazole according to claim 1 , wherein the nitrile compound is a nitrile compound represented by formula (1) wherein “n” is 2.
5. A process for producing 3,4-dichloro-5-cyanoisothiazole according to claim 1 , wherein the nitrile compound is a mixture of nitrile compounds, wherein each nitrile compound is represented by formula (1) wherein “n” is 0, 1 or 2.
6. A process for producing 3,4-dichloro-5-cyanoisothiazole according to claim 1 , wherein the aprotic polar solvent is an amide-based aprotic polar solvent or a carbonate ester-based aprotic polar solvent or a mixture thereof.
7. A process for producing 3,4-dichloro-5-cyanoisothiazole according to claim 6 , wherein the aprotic polar solvent is dimethylformamide, dimethylacetamide, diethylacetamide, N-methylpyrrolidone, tetramethylurea, hexamethylphosphoric triamide, ethylene carbonate or propylene carbonate, or a mixture thereof.
8. A process for producing 3,4-dichloro-5-cyanoisothiazole according to claim 6 , wherein the aprotic polar solvent is dimethylformamide, dimethylacetamide, diethylacetamide, N-methylpyrrolidone, tetramethylurea or a mixture thereof.
9. A process for producing 3,4-dichloro-5-cyanoisothiazole according to claim 1 , wherein the sulfur chloride represented by formula (2) wherein “m” is 1 or 2, or a mixture thereof is prepared in a reaction system.
10. A process for producing 3,4-dichloro-5-cyanoisothiazole according to claim 1 , wherein sulfur chloride represented by formula (2) is sulfur monochloride, wherein “m” is 2.
11. A process for producing 3,4-dichloro-5-cyanoisothiazole according to claim 1 , wherein the nitrile compound represented by formula (1):
(wherein “n” is 1 or 2), is produced by chlorination of succinonitrile represented by formula (4):