METHOD OF PRODUCING FLUORINE-CONTAINING PYRAZOLE CARBOXYLIC ACID HALIDE

Abstract

The invention relates to a method of producing a compound represented by the formula (a) by reacting a compound represented by the formula (c) with a halogenating agent in a non-aqueous system:

##STR00001##

wherein R.sup.1 is a fluoroalkyl group having 1 to 3 carbon atoms, R.sup.2 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R.sup.3 is an alkyl group having 1 to 6 carbon atoms, and X is a halogen atom.

Claims

1. A method of producing a compound represented by the formula (a), which comprises reacting a compound represented by the formula (c) with a halogenating agent in a non-aqueous system: ##STR00013## wherein R.sup.1 is a fluoroalkyl group having 1 to 3 carbon atoms, R.sup.2 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R.sup.3 is an alkyl group having 1 to 6 carbon atoms, and X is a halogen atom.

2. The method according to claim 1, wherein R.sup.1 is a monofluoromethyl group, a difluoromethyl group or a trifluoromethyl group, R.sup.2 is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group or an isopropyl group, and R.sup.3 is a methyl group, an ethyl group, an n-propyl group or an isopropyl group.

3. The method according to claim 2, wherein the halogenating agent is a chlorinating agent, and X is a chlorine atom.

4. The method according to claim 3, wherein the chlorinating agent is chlorine (Cl.sub.2), p-toluenesulfonyl chloride, methanesulfonyl chloride, oxalyl chloride, phosgene, sulfur dichloride, sulfur monochloride, thionyl chloride, sulfuryl chloride or phosphorus pentachloride.

5. The method according to claim 4, wherein the reaction is carried out in the presence of a non-aqueous solvent.

6. The method according to claim 5, wherein the non-aqueous solvent is an aromatic halide or an aliphatic halide.

7. The method according to claim 1, wherein the halogenating agent is a chlorinating agent, and X is a chlorine atom.

8. The method according to claim 7, wherein the chlorinating agent is chlorine (Cl.sub.2), p-toluenesulfonyl chloride, methanesulfonyl chloride, oxalyl chloride, phosgene, sulfur dichloride, sulfur monochloride, thionyl chloride, sulfuryl chloride or phosphorus pentachloride.

9. The method according to claim 8, wherein the reaction is carried out in the presence of a non-aqueous solvent.

10. The method according to claim 9, wherein the non-aqueous solvent is an aromatic halide or an aliphatic halide.

11. The method according to claim 1, wherein the reaction is carried out in the presence of a non-aqueous solvent.

12. The method according to claim 11, wherein the non-aqueous solvent is an aromatic halide or an aliphatic halide.

Description

EXAMPLES

[0071] The present invention is explained in the following by referring to Example, which are not to be construed as limitative. NMR apparatus used for analysis in Example is JNM-ECP400 (400 MHz) manufactured by JEOL Ltd. The unit of yield (%) described in Example is mol %.

Example 1

Synthesis of Compound (a1)

[0072] ##STR00012##

[0073] Sulfur monochloride (5.40 g, 40 mmol) was placed in a reactor. The reactor inside was kept under nitrogen atmosphere, and the system in the below-mentioned reaction was also kept in a non-aqueous state (moisture content: 1000 mass ppm or less).

[0074] First, a non-aqueous solution containing compound (c.sup.1) (1.74 g, 10 mmol), monochlorobenzene (13.4 g) and pyridine (0.12 g, 1.5 mmol) was prepared.

[0075] Next, 1/5 volume of the non-aqueous solution was placed in the reactor while the solution in the reactor was stirred, and the solution in the reactor was heated at 80 to 90 C. for 10 min, and then cooled to 25 C. Then, the residual non-aqueous solution (4/5 volume) was placed in the reactor, and the obtained solution in the reactor was stirred at 25 C. for 22 hr. Then, the solution was stirred at 137 C. for 27 hr. The obtained solution in the reactor was analyzed by .sup.19F-NMR (internal standard material: 3,4,5-trichlorobenzotrifluoride), and thereby, the production of compound (a.sup.1) was confirmed. The yield of compound (a.sup.1) was 88% on the basis of the used amount of compound (c.sup.1).

INDUSTRIAL APPLICABILITY

[0076] As is clear from the above-mentioned results, according to the production method of the present invention, compound (a), i.e., a fluorine-containing pyrazolecarboxylic acid halide, can be obtained in a high-yield of 80% or more, from compound (c), i.e., a fluorine-containing pyrazolylalkylketone, by one-step reaction.