JPH0720908B2 - Fluorine-containing phenone compounds - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fluorinated phenone compound useful as an intermediate for medicines and agricultural chemicals.

[Structure of the Invention] The fluorine-containing phenone compound of the present invention is represented by the following formula (I): Specifically, it represents the following compounds.

2'-chloro-4 ', 5'-difluoro acetophenone (R = CH ₃₎ 2'- chloro-4', 5'-difluoro propiophenone _{(R = C 2 H 5)} 2'- chloro-4 ', 5'-difluoro-butyronitrile phenone _{(R = C 3 H 7)} 2'- chloro-4 ', 5'-difluoro valerophenone _{(R = C 4 H 9)} 2'- chloro-4', 5'-difluoro caproyl phenone (R = C ₅ H ₁₁ ) These fluorinated acetophenones can be easily converted into the corresponding benzoic acid by the following reaction, for example, and are converted into quinolonecarboxylic acid derivatives useful as synthetic antibacterial agents by a known reaction in several steps. be able to.

In the formula, R is preferably CH ₃ and R ¹ is Is.

The compound represented by the general formula (I) can be easily produced by the following reaction formula.

That is, the compound of the formula (II) 1-chloro-3,4-
Difluorobenzene is reacted with a carboxylic acid chloride such as acetyl chloride or a carboxylic acid anhydride such as acetic anhydride in the presence of an acylation catalyst at a temperature of 0 ° C. to 200 ° C., preferably 10 ° C. to 150 ° C. The compound (I) of the present invention can be obtained by isolation.

As the acylation catalyst, AlCl ₃ , SbCl ₅ , FeCl ₃ , FeCl ₂ , TiCl ₄ , BF ₃ , SnCl ₄ , BiCl ₃ , ZnCl
₂ , Lewis acids such as HgCl ₂ , HF, H ₂ SO ₄ , polyphosphoric acid, CH ₃ SO ₃ H, C
_{F 3 SO 3 H, FSO 3} H, γ-CH 3 -C 6 H 4 -SO 3 H, HClO 4, CF 3 CO 2 H, HPO
Bronsted acids such as F ₂ can be mentioned. The amount of the acylation catalyst present is 0.1 to 500 mol%, preferably 1 to 100 mol% based on 1-chloro-3,4-difluorobenzene.
You can select from the range.

The amount of carboxylic acid chloride or carboxylic acid anhydride used is
1 to 10 times the stoichiometric amount necessary for acylating 1-chloro-3,4-difluorobenzene, preferably 1 to
Twice the amount is suitable.

The reaction can be carried out in a solvent or without solvent, and preferable reaction solvents are nitrobenzene, carbon disulfide, dichloromethane, carbon tetrachloride, 1,2-dichloroethane and the like. The reaction conditions such as reaction temperature, time or pressure may be selected as appropriate, but the reaction temperature is about 0 to 200 ° C, preferably 10 to 150 ° C, 0.5 to 10 hours, preferably 1 to 4 hours. Reaction time, 1 to 30 kg / cm ² , preferably 1 to
It can be carried out at a reaction pressure of 5 kg / cm ² .

Hereinafter, examples of the present invention will be described more specifically.

[Example] 23.6 g (0.3 mol) of acetyl chloride was added at 29.7 at 20 ° C to 40 ° C.
Add to a mixture of g (0.2 mol) 1-chloro-3,4-difluorobenzene and 40.0 g (0.3 mol) aluminum chloride and then stir the mixture at 120 ° C. for 2 hours.
The mixture is poured hot on 250 g of ice and the oil which separates is taken up in methylene chloride. After neutralization and washing with water, the solvent was distilled off and the residue was distilled under reduced pressure to obtain 31.2 g (yield 82%) of 2'-chloro-4 ', 5'-difluoroacetophenone. The analytical values for this compound were as follows:

-Boiling point 64-67 ° C / 4-5mmHg-NMR analysis <19Fnmr> δppm from CFl ₃ δ129.9ppm (d, d, d, J _FF = 22.7Hz, J _FF = 9.6Hz, JF _-H = 10.8Hz) δ137.3ppm (d, d, d, J _F−F = 22.7Hz, J _F−H = 7.3 Hz, J _F−H = 10.3Hz) < ¹ Hnmr> δppm from TMS δ7.11 to 7.58 ppm (2H, m) δ2.56ppm (3H, s) ・ IR analysis 1695cm ^-1 (C = 0)

Claims (1)

[Claims] 1. A fluorine-containing phenone compound represented by the following formula (I).