EP1250303A1

EP1250303A1 - Method for preparing alpha-halogenated ketones

Info

Publication number: EP1250303A1
Application number: EP01903977A
Authority: EP
Inventors: Roland Jacquot
Original assignee: Rhodia Chimie SAS
Current assignee: Rhodia Chimie SAS
Priority date: 2000-01-27
Filing date: 2001-01-26
Publication date: 2002-10-23
Also published as: JP2004501864A; FR2804427A1; US20030144541A1; AU2001231920A1; WO2001055067A1; FR2804427B1

Abstract

The invention concerns a method for preparing α-halogenated ketones from secondary α-halogenated alcohols. More particularly, the invention concerns the preparation of α-trihalogenated ketones from secondary α-trihalogenated alcohols. The method for preparing said α-halogenated ketone is characterised in that it consists in oxidising in liquid phase, a secondary α-halogenated alcohol, using molecular oxygen or a gas containing same, in the presence of a catalyst based on a metal M1 selected among metals of group 1b and 8 of the periodic system of elements and optionally an activating element.

Description

PROCESS FOR THE PREPARATION OF α-HALOGENATED KETONES.

The present invention relates to a process for the preparation of α-halogenated ketones from α-halogenated secondary alcohols. The invention relates more particularly to the preparation of α-trihalogenated ketones from α-trihalogenated secondary alcohols

It is known to prepare a trihalogenated ketone according to a process which consists in reacting an organometallic compound with trifluoroacetic acid or its esters [Chem. L S. et al, J. Fluorine Chem. WINE, p. 117 (1981)].

This process suffers from several drawbacks. It comprises several stages, preparation of the organometallic compound from bromobenzene then reaction with trifluoroacetic acid at low temperature (-78 ° C) and hydrolysis which complicates its implementation and it is difficult to transpose to industrial scale.

In addition, the reaction yield is not satisfactory due to the formation of by-products.

The objective of the present invention is to provide a new method which overcomes the aforementioned drawbacks.

It has now been found and this is what constitutes the object of the present invention, a process for the preparation of an α-halogenated ketone characterized in that it consists in oxidizing in the liquid phase, a secondary alcohol α- halogenated, using molecular oxygen or a gas containing it, in the presence of a catalyst based on a metal M- | chosen from the metals of group 1b and 8 of the periodic table.

A preferred variant of the process of the invention consists in also adding, as activators, metals such as cadmium, cerium, bismuth, lead, silver, tellurium, tin or germanium.

An object of the invention is therefore to provide a very general process for obtaining α-halogenated ketones from α-halogenated secondary alcohols corresponding to the general formula (I): Y,

Q - C C - Y,

OH V

(l) in said formula, Q represents a monovalent hydrocarbon group, optionally substituted having from 1 to 40 carbon atoms, Y ₍ Y ₂ and Y ₃ , identical or different, represent a hydrogen atom or a halogen atom, chlorine, fluorine, bromine, iodine and, preferably, fluorine or a perhaloalkyl group having from 1 to 10 carbon atoms and at least one of the groups Yi, Y ₂ and Y ₃ , represent a halogen atom.

Among the compounds of formula (I), those which are preferred correspond to formula (I) in which at least two of the groups Y ^ Y ₂ and Y ₃ represent a halogen atom, and even more preferably all the groups Y _{1 τ} Y ₂ and Y ₃ represent a halogen atom, preferably a fluorine atom.

The invention also contemplates that the group CY- | Y ₂ Y ₃ represents a perhaloalkyl group, preferably a perfluoroalkyl group and more preferably a trifluoromethyl group. In formula (I), the group -CHOH-CYιY ₂ Y ₃ is called

"halomethylethylcarbinol".

The characteristic of the process of the invention consists in carrying out the oxidation of the α-halogenated secondary alcohols to corresponding ketones in an aqueous or organic medium, in the presence of a catalyst based on a metal M- _j chosen from the metals of group 1b and 8 and possibly an activator.

For the definition of metallic elements, reference is made below to the

Periodic classification of elements published in the Society Bulletin

Chimique de France, n ° 1 (1966).

More specifically, the α-halogenated secondary alcohols serving as starting products for the preparation of ketones correspond to the general formula (I) in which Q represents a monovalent hydrocarbon group, substituted or not, which can be an acyclic saturated or unsaturated aliphatic group, linear or branched; a saturated, unsaturated or aromatic, monocyclic or polycyclic carbocyclic or heterocyclic group. Particularly suitable for implementing the process of the invention, the α-halogenated secondary alcohols of general formula (I) in which Q represents a monocyclic aromatic hydrocarbon group or polycyclic; the groups being able to form between them orthocondensed systems (for example the naphthyle group) or ortho and pericondenses.

Q preferably represents an aryl group corresponding to the general formula (II):

(II)

in said formula (II):

- n is an integer from 0 to 5, preferably from 0 to 3,

- R represents R- _| , one of the following groups or functions:. an alkyl group, linear or branched, having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl,. a haloalkyl group having from 1 to 6 carbon atoms, mono-, poly- or perhaloalkyl and from 1 to 13 halogen atoms,. a linear or branched alkenyl group having from 2 to 6 carbon atoms, preferably from 2 to 4 carbon atoms, such as vinyl, allyl,. a linear or branched alkoxy or thioether group having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, groups. a group of formula - OH

- COOH

- CHO

- CN

-N- (R ₂ ) ₂ - X

- CF ₃ in said formulas, the groups R? identical or different, represent a hydrogen atom, a linear or branched alkyl group having from 1 to 6 carbon atoms and even more preferably from 1 to 4 carbon atoms or a phenyl group and X symbolizes a halogen atom, in particular a chlorine or bromine atom,

- R represents R ₃ one of the following more complex groups: in which :

Ri has the meaning given above,

R represents a valential bond or a divalent, linear or branched, saturated or unsaturated hydrocarbon group having from 1 to 4 carbon atoms such as, for example, methylene ethylene, propylene, isopropylene, isopropylidene, and m is an integer from 0 to 3,. a group R ₄ - A - R5 in which: R4 has the meaning given above,

R ₅ represents a linear or branched alkyl group having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms or a group

and to one of the following groups:

- O -, - CO -, - COO -, - N -, - CO - N -,

IIR ₂ R ₂ in these formulas, m, R- | and R ₂ have the meaning given above.

When n is greater than 1, the groups R can be identical or different and 2 successive carbon atoms of the benzene ring can be linked together by a cetal bridge such as the methylene dioxy or ethylene dioxy groups extranuclear.

Preferably, n is equal to 0, 1 2 or 3.

Among all the abovementioned groups Q, it is most preferably used in the process of the invention, the α-halogenated secondary alcohols corresponding to the general formula (I) in which Q represents an aryl group corresponding to the general formula (II) in which :

- n is equal to 0, 1, 2 or 3,

- R represents one of the following function groups:

. a linear or branched alkyl group having from 1 to 4 carbon atoms,. a linear or branched alkoxy or thioether group having from 1 to 4 carbon atoms, . a methylene or ethylene dioxy group,

. an -OH group.

As examples of α-halogenated secondary alcohols corresponding to the general formula (I) in which Q represents an aryl group of general formula (II), there may be mentioned: 2-hydroxy-1-phenyl-trichloromethylcarbinol, 2-hydroxy-1- phenyl-trifluromethylcarbinol, 3-hydroxy-1-phenyl-trichloromethylcarbinol, 3-hydroxy-1-phenyl-trifluromethylcarbinol, 4-hydroxy-1-phenyl-trichloromethylcarbinol, 4-hydroxy-1- phenyl-trifluoromethylcarbinol, 2-hydroxy-3-methyl-1-phenyl-trichloromethylcarbinol, 2-hydroxy-3-methyl-1 - phenyl-trifluoromethylcarbinol, 2-hydroxy-4-methyl-1-phenyl- trichloromethylcarbinol, 2-hydroxy-4-methyl-1-phenyl-trifluoromethylcarbinol, 2-hydroxy-5-methyl-1-phenyl-trichloromethylcarbinol, 2-hydroxy-5-methyl-1-phenyl-trifluoromethylcarbinol, 3-hydroxy-4 -methyl-1-phenyl- trichloromethylcarbinol, 3-hydroxy-4-methyl-1 -phenyl-trifluoromethylcarbinol, 2-methoxy-1-phenyl-trichloromé thylcarbinol, 2-methoxy-1-phenyl-trifluoromethylcarbinol, 3-methoxy-1-phenyl-trichloromethylcarbinol, 3-methoxy-1-phenyl-trifluoromethylcarbinol, 4-methoxy-1-phenyl- trichloromethylcarbinol, 4-methoxy -1-phenyl-trifluoromethylcarbinol, 5-methoxy-1 -phenyl-trichloromethylcarbinol, 5-methoxy-1-phenyl- trifluoromethylcarbinol, 3-hydroxy-4-methoxy-1 -phenyl-trichloromethylcarbinol, 3-hydroxy-4 -methoxy-1-phenyl-trifluoromethylcarbinol, 4-hydroxy-3-methoxy- 1 -phenyl-trichloromethylcarbinol, 4-hydroxy-3-methoxy-1 -phenyl- trifluoromethylcarbinol, 3-hydroxy-4,5-dimethoxy- 1-phenyl- trichloromethylcarbinol, 3-hydroxy-4,5-dimethoxy-1-phenyl- trifluoromethylcarbinol, 4-hydroxy-3,5-dimethoxy-1 -phenyl- trichloromethylcarbinol, 4-hydroxy-3,5-dimethoxy -1 -phenyl- trifluoromethylcarbinol, 5-hydroxy-1-phenyl-3-bis (trichloromethylcarbinol), 5-hydroxy-1-phenyl-3-bis (trifluoromethylcarbinol), 4 -hydroxy-3,5-dimethoxy-1-phenyl-trichloromethylcarbinol, 4-hydroxy-3,5-dimethoxy-1-phenyl-trifluoromethylcarbinol, 2-hydroxy-3-amino-1-phenyl-trichloromethylcarbinol, 2- hydroxy-3-amino-1-phenyl-trifluoromethylcarbinol, 2-hydroxy-4-amino-1-phenyl-trichloromethylcarbinol, 2-hydroxy-4-amino-1 -phenyl-trifluoromethylcarbinol, 2-hydroxy-5-amino -1-phenyl-trichloromethylcarbinol, 2-hydroxy-5-amino-1 -phenyl-trifluoromethylcarbinol, 3-hydroxy-2-amino-1- phenyl-trichloromethylcarbinol, 3-hydroxy-2-amino-1 -phenyl- trifluoromethylcarbinol, 2,3-dihydroxy-1-phenyl-trichloromethylcarbinol, 2,3-dihydroxy-1-phenyl-trifluoromethylcarbinol, 2,4-dihydroxy-1-phenyl- trichloromethylcarbinol, 2,4-dihydroxy-1- phenyl-trifluoromethylcarbinol, 2,5- dihydroxy-1-phenyl-trichloromethylcarbinol, 2,5-dihydroxy-1-phenyl- trifluoromethylcarbinol, 2,6-dihydroxy-1-phenyl-trichloromethylcarbinol, 2,6-dihydroxy-1 -phenyl-trifluoromethylcarbinol, 4-dihydroxy-1 -phenyl- trichloromethylcarbinol, 3,4-dihydroxy-1 -phenyl-trifluoromethylcarbinol, 3,5- dihydroxy-1 -phenyl-trichloromethylcarbinol, 3,5-dihydroxy-1 -phenyl- trifluoromethylcarbinol, 3,5-dihydroxy-4-methyl-1 -phenyl- trichloromethylcarbinol, 3,5-dihydroxy-4-methyl-1 -phenyl- trifluoromethylcarbinol, 2,3,4-trihydroxy-1 -phenyl-trichloromethylcarbinol, 2 , 3,4-trihydroxy-1-phenyl-trifluoromethylcarbinol, 2,4,6-trihydroxy-1 -phenyl- trichloromethylcarbinol, 2,4, 6-trihydroxy-1-phenyl-trifluoromethylcarbinol, 3,4, 5- trihydroxy-1-phenyl-trichloromethylcarbinol, 3,4,5-trihydroxy-1-phenyl-trifluoromethylcarbinol.

In the general formula (I) of the α-halogenated secondary alcohols, Q can represent a carbocyclic group saturated or comprising 1 or 2 unsaturations in the ring, generally having 3 to 7 carbon atoms, preferably 6 carbon atoms in the cycle; said ring being able to be substituted by 1 to 5 groups R- |, preferably 1 to 3, R- | having the meanings set out above for the substituents of the aryl group of general formula (II).

As preferred examples of groups Q, mention may be made of cyclohexyl or cyclohexene-yl groups, optionally substituted by linear or branched alkyl groups, having from 1 to 4 carbon atoms.

As examples of α-halogenated secondary alcohols of formula (I) in which Q is a cycloaliphatic group, mention may be made in particular of 1- (trichloromethylcarbinol) -l -cyclohexene, 1 - (trifluoromethylcarbinol) -l - cyclohexene , 1- (trichloromethylcarbinol) -1-cyclohexane, 1- (trifluoromethylcarbinol) -l-cyclohexane, 1-methyl-2- (trichloromethylcarbinol) -1- cyclohexene, 1-methyl-2- (trifluormethylcarbinol) -1 - cyclohexene, 1-methyl-2- (trichloromethylcarbinol) -cyclohexane, 1 -methyl-2- (trifluoromethylcarbinol) - cyclohexane, 1-methyl-4-isopropyl-2- (trichloromethylcarbinol) -1 -cyclohexene -methyl-4-isopropyl-2- (trifluoromethylcarbinol) -1 -cyclohexene, 1-methyl-4-isopropyl-2- (trichloromethylcarbinol) -cyclohexane, 1 -methyl-4-isopropyl-2- (trifluoromethylcarbinol) -cyclohexane .

As mentioned previously, Q can represent an acyclic aliphatic group, saturated or unsaturated, linear or branched. More precisely, Q represents an alkyl, alkenyl, alkadienyl, alkynyl, linear or branched group preferably having from 1 to 12 carbon atoms.

The hydrocarbon chain can optionally be: - interrupted by one of the following groups: O CO COO -N-, -CO-N

1 1

1 1 in these formulas R „has the meaning given above, - and / or carries one of the following substituents:

- OH, - COOH, - CHO, - CN, - N (R ₂ ) ₂ , - X, - CF ₃ in these formulas R ₂ has the meaning given above.

The acyclic, saturated or unsaturated, linear or branched aliphatic group may optionally carry a cyclic substituent. By cycle is meant a carbocyclic or heterocyclic, saturated, unsaturated or aromatic cycle.

The acyclic aliphatic group can be linked to the cycle by a valential link or by one of the following groups:

-O-, -CO-, -COO-, -N-, -CO-N-,

IIR ₂ R ₂ in these formulas R has the meaning given above.

As examples of cyclic substituents, it is possible to envisage cycloaliphatic, aromatic or heterocyclic, in particular cycloaliphatic substituents comprising 6 carbon atoms in the ring or benzene, these cyclic substituents themselves being optionally carriers of 1, 2, 3, 4 or 5 R _π , identical or different, R- | having the meaning given above.

As examples of α-halogenated secondary alcohols of formula (I) in which Q represents an aliphatic group, there may be mentioned in particular: 1,1,1-trifluoro-2-pentanol, 4-methyl-1, 1,1-trichloro-2-pentanol, 1,1,1-tririforo-2-hexanol, 3,3-dimethyl-1,1,1-trifluoro-2-butanol, 2-hydroxy-4-methoxy -1,1,1- trichloro-5-pentanol, 1,1,1-trichloro-2-heptanol, 5-hydroxy 4-methyl-6,6,6- trichloro-3-hexanone, 2-hydroxy -1,1,1-trichloro-4-octanone, 2-hydroxy-6-methyl-1,1,1-trichloro-4-heptanone, 4-ethyl-1,1,1-trichloro-2-hexanol , 3-ethyl-1,1,1-trichloro-2-heptanol, 2-hydroxy-1,1,1-trichloro-4-nonanone, 2-hydroxy- 7-methyl-1, 1,1 - trichloro-4-octanone, 1,1,1 -trichloro-4,6,6-trimethyl-2-heptanol 1,1,1-trichloro-2-nonanol, 2-hydroxy-1,1,1- trichloro-4-decanone, 2-hydroxy-1,1,1-trichloro-4-undecanone, 1,1,1-trichloro-2-dodecanol; 1,1,1-trichloro-3-pentene-2-ol, 1,1,1-trifluoro-3-pentene-2-ol,, 3-methyl-1,1,1-trichloro-3- butene-2-ol, 5,5,5-trichloro-1-pentene-4-ol, 4-methyl-1,1,1-trichloro-3-pentene-2-ol, 3-methyl-1 , 1,1-trichloro-3-pentene-2-ol, 4-methyl-1,1,1 - trifluoro-3-pentene-2-ol, 3,4-dimethyl-1,1,1-trichloro -3-pentene-2-ol, 4-ethyl- 1,1,1-trichloro-3-hexene-2-ol, 1,1,1-trifluoro-4-hexene-2-ol, 1, 1,1-trichloro-3-nonene-2-ol, 1,1,1,4-tetrachloro-3-nonene-2-ol, 1,1,1-trichloro-3-dodecene-2-ol; 1,1,1-trifluoro-4-octene-2-ol, 7-bromo-1,1,1-trichloro-7-octene-3-yne-2-ol, 8-bromo-1, 1, 1-trichloro-7-octene-3-yne-2-ol, 1, 1, 1-trichloro-3-nonyne-2-ol, 1, 1, 1-trichloro -3-decyne-2-ol; 1, 1, 1-trichloro-4- (4-methyl-3-cyclohexene-1-yl) - 3-pentene-2-ol; 9-trichloroethylol limonene, (3,4,5,6-tetrahydro) -4-nonatolyl- 1, 1, 1-trichloro-2-pentanol, 4-phenyl-1, 1, 1-trichloro-3- pentene-2-ol, 4-phenyl- 1, 1, 1-trichloro-2-pentanol, 4,6,6-trimethyl-1, 1, 1-trichloro-3-heptene-2-ol, 4 , 6,6-trimethyl-1, 1, 1-trichloro-2-heptanol, 5-methyl-1, 1, 1-trichloro-5-hexene-2- ol, 5-methyl-1, 1, 1 -trichloro-2-hexanol, 3,4-dimethyl-1, 1, 1-trichloro-2-pentanol. Q can also represent a monovalent heterocyclic group, saturated or not, comprising in particular 5 or 6 atoms in the ring including 1 or 2 heteroatoms such as the nitrogen, sulfur and oxygen atoms, the carbon atoms of the heterocycle which may optionally be substituted, in their entirety or for a part of them only by R- groups | , R- | having the meaning given above for the substituents of the aryl group of formula (II). Q can also represent a polycyclic heterocyclic group defined as being either a group consisting of at least 2 aromatic or non-aromatic heterocycles containing at least one heteroatom in each cycle and forming between them systems ortho or ortho and pericondenses or is a group constituted by at least an aromatic or non-aromatic hydrocarbon cycle and at least one aromatic or non-aromatic heterocycle forming between them ortho or ortho and pericondenses systems.

As examples of α-halogenated secondary alcohols of formula (I) in which Q represents a heterocyclic group, mention may be made of 2-furyl-trichloromethylcarbinol, 2-furyl-trifluoromethylcarbinol, 1 - (5-methylfuryl) - trichloromethylcarbinol, 1- (5-N, N-diethylfuramide) -trichloromethylcarbinol, la (2,2,2-trifluoro-1-ethanol) -3-pyridine, 2-amino-4-hydroxy-6-methyl-5 -

(trichloromethylcarbinol) -pyrimidine, 2-amino-4-hydroxy-6-methyl-5-

(trifluoromethylcarbinol) -pyrimidine, 4-hydroxy-6-methyl-2-methylamino-5- (2,2,2-trichloro-1-hydroxyethyl) pyrimidine, 2-dimethylamino-4-hydroxy-6-methyl- 5 - (2,2,2-trichloro-1-hydroxyethyl) pyrimidine.

The starting α-halogenated secondary alcohols which can be oxidized to ketones according to the method of the invention are obtained by methods described in the literature. In particular, they can be prepared by one or other of the methods of preparation cited by J.H.T. LEDRUT and G. COMBES in "Belgian chemical industry" n ° 6 (1962) p. 635 to 652.

Among these various processes for obtaining α-halogenated secondary alcohols, some are more suitable than others for the preparation of certain families of this type of compound. Thus, for example, compounds with mobile hydrogen can react with chloral (or bromal) to give the corresponding α-halogenated secondary alcohol.

An acid catalyst such as aluminum chloride can be used to react aromatic hydrocarbons such as veratrole (or 1,2-dimethoxybenzene) with chloral. For this type of preparation, we can refer, in addition to the previously cited article, to the article by R. QUELET in the

Bulletin of the Chemical Society of France (1954), p. 932.

Starting from phenols, the chloral can be reacted in the presence of anhydrous potassium carbonate [see M. PAULY Berichte der Deutschen Gesellschaft 56, 979 (1923)].

One can also use α-halogenated secondary alcohols prepared according to applications PCT / FR / 99/01235 and PCT / FR / 99/01379 in the name of the applicant.

The catalysts involved in the process of the invention are based on a metal from group 1b and 8 of the periodic table.

Examples of catalysts based on a metal from group 8 of the periodic table include nickel, noble metals such as ruthenium, rhodium, palladium, osmium, iridium, platinum and their mixtures. For group 1b metals, copper is preferred.

Preferably used, platinum and / or palladium catalysts, taken in all the available forms such as for example: platinum black, palladium black, platinum oxide, palladium oxide or the metal noble itself deposited on various supports such as carbon black, calcium carbonate, activated aluminas and silicas or equivalent materials. Carbon black based catalytic masses are particularly suitable.

The amount of this catalyst to be used, expressed by weight of metal M ^ relative to that of the compound of formula (I) can vary from 0.01 to 10% and, preferably, from 0.04 to 2%.

For more details on the catalysts, reference may be made to US-A-3,673,257, FR-A-2,305,420, FR-A-2,350,323.

The activator can be chosen from all those mentioned in the aforementioned patents. Preferably, use is made of bismuth, lead and cadmium, in the form of free metals or cations. In the latter case, the associated anion is not critical and any derivatives of these metals can be used. Preferably, metal bismuth or its derivatives are used. We can use a mineral or organic derivative of bismuth in which the bismuth atom is at a degree of oxidation greater than zero, for example equal to 2, 3, 4 or 5. The remainder associated with bismuth n ' is not critical from the moment that it satisfies this condition. The activator can be soluble or insoluble in the reaction medium.

Illustrative compounds of activators which can be used in the process according to the present invention are: bismuth oxides; bismuth hydroxides; the salts of mineral hydracids such as: chloride, bromide, iodide, sulfide, selenide, bismuth tellurium; the mineral oxyacid salts such as: sulfite, sulfate, nitrite, nitrate, phosphite, phosphate, pyrophosphate, carbonate, perchlorate, antimoniate, arsenate, selenite, bismuth selenate; oxyacid salts derived from transition metals such as: vanadate, niobate, tantalate, chromate, molybdate, tungstate, bismuth permanganate.

Other suitable compounds are also salts of aliphatic or aromatic organic acids such as: acetate, propionate, benzoate, salicylate, oxalate, tartrate, lactate, bismuth citrate; phenates such as: bismuth gallate and pyrogallate. These salts and phenates can also be bismuthyl salts.

As other inorganic or organic compounds, binary combinations of bismuth with elements such as phosphorus and arsenic can be used; bismuth-containing heteropolyacids and their salts; aliphatic and aromatic bismuthines are also suitable.

As specific examples, we can cite:

- as oxides: BiO; Bi ₂ θ3: Bi ₂ O; Bi ₂ θ5. - as hydroxides: Bi (OH) 3,

- as mineral hydracid salts: bismuth chloride BiCI ₃ ; bismuth bromide BiBr ₃ ; bismuth iodide BH3; bismuth sulfide Bi S ₃ ; bismuth selenide Bi Sβ3: bismuth tellurium Bi ₂ Tβ3,

- as mineral oxyacid salts: basic bismuth sulfite Bi ₂ (SO ₃ ) ₃ , Bi ₂ O ₃ , 5H O; neutral bismuth sulfate Bi ₂ (SO) 3; bismuthyle sulfate

(BiO) HSO ₄ ; bismuthyl nitrite (BiO) NO ₂ , 0.5H ₂ O; neutral bismuth nitrate Bi (NO ₃₎ _3, 5H O; bismuth and magnesium double nitrate 2Bi (N0 ₃ ) ₃ , 3Mg (NO ₃ ) ₂ , 24H ₂ O; bismuthyl nitrate (BiO) NO ₃ ; bismuth phosphite Bi (PO3H), 3H ₂ O; bismuth neutral phosphate BiPO ₄ ; bismuth pyrophosphate Bi (P ₂ O) ₃ ; bismuthyl carbonate (BiO) ₂ CO ₃ , O, 5H ₂ O; neutral bismuth perchlorate Bi (CIO) ₃ , 5H ₂ O; bismuthyl perchlorate (BiO) CIO ₄ ; bismuth antimoniate BiSbO; the neutral arsenate of bismuth Bi (AsO ₄ ) ₃ ; bismuthyl arsenate (BiO) AsO ₄ , 5H ₂ O; bismuth selenite Bi ₂ (SeO ₃ ) 3.

- as oxyacid salts derived from transition metals: bismuth vanadate BiVO ₄ ; bismuth BiNbO niobate: bismuth tantalate BiTaO ₄ ; bismuth neutral chromate Bi ₂ (CrO ₄ ); bismuthyl dichromate [(BiO) ₂ ] Cr ₂ O ₇ ; bismuthyl acid chromate H (BiO) CrO ₄ ; bismuthyl potassium potassium chromate K (BiO) CrO ₄ ; bismuth Bi molybdate (MoO ₄ ) 3; bismuth tungstate Bi ₂ (WO) ₃ ; bismuth sodium sodium molybdate NaBi (MoO ₄ ) ₂ ; bismuth basic permanganate Bi ₂ O ₂ (OH) MnO ₄ .

- as salts of aliphatic or aromatic organic acids: bismuth acetate Bi (C ₂ H ₃ O ₂ ) 3; bismuthyl propionate (BiO) C ₃ H ₅ O ₂ ; basic bismuth benzoate C6H ₅ CO ₂ Bi (OH); bismuthyl salicylate C ₆ H ₄ CO ₂ (BiO) (OH); bismuth oxalate (C ₂ O ₄ ) ₃ Bi ₂ ; bismuth tartrate Bi ₂ (C ₄ H ₄ O ₆ ) ₃ , 6H ₂ O; bismuth lactate (C ₆ H ₉ O ₅ ) OBi, 7H ₂ O; bismuth citrate C ₆ H ₅ O ₇ Bi.

- as phenates: basic bismuth gallate Cγ \ - -? OγB \; bismuth basic pyrogallate C ₆ H ₃ (OH) ₂ (OBi) (OH).

As other mineral or organic compounds are also suitable: bismuth phosphide BiP; bismuth arsenide Bi3As; sodium bismuthate NaBiO ₃ ; bismuth-thiocyanic acids H [Bi (BNS) ₅ ], H ₃ [Bi (CNS) e] ^and their sodium and potassium salts; trimethylbismuthine Bi (CH ₃ ) ₃ , triphenylbismuthine Bi (C ₆ H ₅ ) ₃ .

The bismuth derivatives which are preferably used to carry out the process according to the invention are: bismuth oxides; bismuth hydroxides; bismuth or bismuthyl salts of mineral hydracids; bismuth or bismuthyl salts of mineral oxyacids; bismuth or bismuthyl salts of aliphatic or aromatic organic acids; and bismuth or bismuthyl phenates. A group of activators which are particularly suitable for carrying out the invention consists of: bismuth oxides Bi ₂ θ3 and Bi ₂ O ₄ ; bismuth hydroxide Bi (OH) ₃ ; neutral bismuth sulfate Bi ₂ (SO ₄ ) ₃ ; bismuth chloride BiCl3; bismuth bromide BiBr3; bismuth iodide Bil ₃ ; neutral bismuth nitrate Bi (NO ₃₎ _3, 5H O; bismuthyl nitrate BiO (NO ₃ ); bismuthyl carbonate (BiO) ₂ CO ₃ , O, 5H ₂ O; bismuth acetate Bi (C ₂ H ₃ O ₂ ) ₃ ; bismuthyl salicylate C ₆ H ₄ CO ₂ (BiO) (OH).

The quantity of activator used, expressed by the quantity of metal contained in the activator relative to the weight of the metal Mi engaged, can vary within wide limits. For example, this amount can be as small as 0.1% and can reach 100% by weight of metal M- _| engaged and even exceed it without inconvenience. Advantageously, it is around 50%.

Depending on the nature of the starting substrate, the method of the invention can be carried out according to several embodiments.

Thus, if the starting α-halogenated secondary alcohol corresponds to formula (I) in which Q is an aryl group and carries at least one hydroxyl group, it is advantageous to react this compound of phenolic type, in salified form.

In this case, the catalytic entity may or may not be formed in situ by successive or simultaneous introduction of the catalyst based on the metal M- _j and of the activator.

If the starting α-halogenated secondary alcohol is not a phenolic compound, it is possible to carry out the oxidation reaction, in an organic solvent, without the introduction of a base. In this case, it is desirable to prepare the catalytic entity consisting of the metal M- beforehand _. and activator.

More specifically, according to the first embodiment of the invention, involving an alcohol of formula (I) carrying a halogenomethylcarbinol group and a hydroxyl group, the oxidation reaction is carried out in an aqueous medium containing in solution a basic agent, and more particularly ammonium hydroxide, alkaline or alkaline-earth bases, among which mention may be made of hydroxides such as sodium, potassium or lithium hydroxide; alkali alkanolates such as sodium or potassium methylate, ethylate, isopropylate and tert-butoxide, sodium or potassium carbonates or bicarbonates and, in general, the salts of alkaline or alkaline-earth bases and weak acids.

Thus, the starting alcohol of formula (I) carries a hydroxyl group which is preferably salified before the implementation of the oxidation reaction. For economic considerations, sodium or potassium hydroxide is used. The proportion of mineral base to be used is preferably such that the ratio between the number of moles OH "and the number of moles of compound of formula (I) varies between 1 and 2.

The concentration by weight of the alcohol of formula (I) in the liquid phase is usually between 1% and 40%, preferably between 2% and 30%. Practically one way of carrying out the process consists in bringing into contact with molecular oxygen or a gas containing it, for example air, the solution containing the alcohol of formula (I), the basic agent, the catalyst based of metal M ^ optionally the activator, according to the proportions indicated above.

A preferred embodiment of the invention consists first of carrying out the salification of the alcohol of formula (I) before the oxidation reaction. From a practical point of view, the alcohol of formula (I) and the basic agent are charged and the compound is obtained in salified form at room temperature (most often between 15 ° C and 25 ° C).

Then introduced the catalyst based on the metal M ₁ and optionally the activator. The reaction mixture kept under scanning of oxygen or of a gas containing it is brought to the desired reaction temperature.

According to the invention, the oxidation temperature is preferably chosen, in a temperature range from 40 ° C to 100 ° C.

We generally operate at atmospheric pressure, but we can work under pressure between 1 and 20 bar.

The mixture is then stirred at the desired temperature until consumption of an amount of oxygen corresponding to that necessary to transform the carbinol group into a carbonyl group.

At the end of the reaction, which preferably lasts between 30 minutes and 6 hours, the ketone compound corresponding to formula (III) is recovered:

Q - C - C I '- Y

O γ ₃

(III) in said formula Q and Yi, Y ₂ and Y ₃ , have the meaning given above.

Then, after cooling if necessary, the catalytic mass is separated from the reaction medium, for example by filtration. In a following step, the resulting medium is acidified by adding a protonic acid of mineral origin, preferably hydrochloric acid or sulfuric acid or an organic acid such as, for example, trifluromethanesulfonic acid or l methanesulfonic acid until a pH less than or equal to 5. The concentration of the acid is indifferent and use is preferably made of commercial forms.

Acidification is usually done at room temperature. The ketone compound of formula (III) is then recovered according to conventional techniques, for example by extraction with the aid of an appropriate organic solvent, for example an aromatic hydrocarbon, halogenated or not, and there may be mentioned more particularly toluene or mono- or dichlorobenzene.

According to another embodiment of the invention, one starts with an α-halogenated secondary alcohol which is a compound of any aliphatic or aromatic type but which is not of the phenolic type (namely an aromatic compound carrying a hydroxyl group). In this case, the reaction is advantageously carried out in water or in an organic solvent when the α-halogenated secondary alcohol is not sufficiently soluble in water, for example a solubility in water, at ambient temperature, less than 20% by weight.

An organic solvent is used, inert under the reaction conditions and making it possible to at least partially solubilize the starting compound.

As more specific examples, mention may in particular be made of ester type solvents and more particularly butyl acetate, amyl acetate, ethyl phthalate. The concentration of the starting substrate in the solvent is preferably between 10 and 30% by weight.

As mentioned previously, it is preferable to prepare the catalytic entity, extemporaneously.

It is possible, by way of example, to prepare the catalytic entity (catalyst M- | / activator), for example by taking a catalyst of a metal Mi deposited on a support, preferably activated carbon, silica or l alumina, then introduce the compound providing the activating element, in the presence of a base, preferably sodium carbonate.

Thus, the catalyst based on a metal M ^ and an activator is obtained. The catalytic entity can also be reduced by a reducing agent such as, for example, hydrogen, formalin or hydrazine.

The temperature of the oxidation reaction is preferably chosen in a temperature range from 100 ° C to 160 ° C.

From a practical point of view, the compound of formula (I) is charged, the organic solvent and the catalyst. The reaction mixture kept under scanning of oxygen or of a gas containing it is brought to the desired reaction temperature.

In an organic medium, the water formed during the reaction is removed continuously, by distillation or physical entrainment by the gas.

At the end of the reaction, which preferably lasts between 30 minutes and 6 hours, the ketone compound corresponding to formula (III) is recovered most often by distillation.

The invention also relates to the α-halogenated ketones corresponding to the general formula:

Q - C - C - Y,

O Y,

(IV) in said formula, Q has the meaning given above and Q preferably represents an aliphatic radical as defined above and Y _1} Y ₂ and Y ₃ represent a hydrogen atom or a fluorine atom and Y _1} Y ₂ and Y ₃ represent at least one fluorine atom, preferably three fluorine atoms.

An exemplary embodiment of the invention is given below by way of illustration and without limitation. In the examples, the abbreviations used are defined as follows:

The conversion rate (TT) corresponds to the ratio between the number of substrates transformed and the number of moles of substrate engaged.

The yield (RR) corresponds to the ratio between the number of moles of product formed and the number of moles of substrate used. The weight of the noble metal is expressed in% by weight relative to the total weight of the catalyst (active phase + support).

Example 1

Preparation of 4-trifluoroacetylanisole 4 g of 2,2,2-trifluoro-1- (4-methoxybenzene) ethanol are introduced into a 100 ml glass reactor.

40 ml of butyl acetate are added. Stirred and introduced 0.5 g of catalyst 4.7% Pt + 1.5% Bi / C containing 50% water, product sold by Engelhard.

The mixture is heated to 125 ° C. and a current of air is passed through the sky above the reactor. After 6 hours of reaction, the yield (RR) is 99% assayed by gas chromatography.

Example 2

Example 1 is repeated, but with a catalyst comprising 5.3% Pd + 3% Bi.

After 6 hours of reaction, the yield (RR) is 13%.

Example 3

Preparation of 4-trifluoroacetyl-2-hvdroxy-toluene 4 g of 2,2,2-trifluoro-1- (2-hydroxy-3-methylbenzene) ethanol are introduced into a 100 ml glass reactor.

40 ml of water are added.

Stirred and added 0.5 g of a catalyst comprising 5.4% Pt + 1.8% Bi / C containing 50% water. It is heated to 80 ° C. and a stream of air is passed through the solution.

After 15 hours under these conditions, the yield (RR) is 95% assayed by gas chromatography.

Example 4 Example 3 is repeated, but using 40 ml of butyl acetate.

The reaction is carried out at 125 ° C. After 6 hours of reaction, the yield (RR) is 96%.

Example 5 Preparation of 4-trifluoroacetyl-2-hydroxy-toluene

4 g of 2,2,2-trifluoro-1- (2-hydroxy-3-methylbenzene) ethanol are introduced into a 100 ml glass reactor.

40 ml of water and 0.8 g of sodium hydroxide are added. Stirred and introduced 0.5 g of catalyst at 5% Pt C containing 50% water.

17 mg of Bi ₂ O _{3 are then added} .

The mixture is heated to 80 ° C. and a stream of air is passed by bubbling through the reaction medium. After 8 hours of reaction, the yield (RR) is 96%.

Example 6

Preparation of 2,6-trifluoroacetyl-nonyl-4-phenol 8 g of 2,6 (2,2,2-trifluoro-1-ethanol) -4-nonylphenol are introduced into a 100 ml glass reactor.

40 ml of water and 1.3 g of NaOH are added in pellets. The mixture is stirred and 0.8 g of 5% Pt / C catalyst containing 50% water and 27 mg of Bi ₂ O _{3 is added} . It is heated to 80 ° C. and a stream of air is bubbled through.

After 15 hours of reaction, the yield (RR) is 94%.

Example 7

Preparation of 1, 1, 1-trifluoro-4-nonene-2-one cis + trans 4 g of trifluoro-1, 1, 1-hydroxy-2-nonene-4 cis + trans are introduced into a glass reactor of 100 ml.

40 ml of butyl acetate are added and the mixture is stirred.

0.5 g of catalyst 4.7% Pt + 1.5 Bi / C containing 50% water is then introduced. The mixture is heated to 125 ° C. and a stream of air is passed through the reaction medium.

After 8 hours of reaction, a yield (RR) of 94% is obtained.

Example 8 Preparation of 3- (trifluoroacetyl) pyridine

5 g of (2,2,2-trifluoro-1-ethanol) -3-pyridine are introduced into a 100 ml glass reactor.

40 ml of butyl acetate are added and the mixture is stirred.

0.5 g of catalyst 4.7% Pt + 1.5 Bi / C supported on activated carbon is then introduced.

The mixture is heated to 125 ° C. and a stream of air is passed through the reaction medium.

After 10 hours of reaction, a yield (RR) of 68% is obtained by assay by gas chromatography.

Claims

1 - Process for the preparation of an α-halogenated ketone characterized in that it consists in oxidizing in the liquid phase, an α-halogenated secondary alcohol, using molecular oxygen or a gas containing it, in the presence of a catalyst based on a metal M- | chosen from the metals of group 1b and 8 of the periodic table.

2 - Method according to claim 1 characterized in that the α-halogenated secondary alcohol corresponds to the general formula (I):

Q - C C - Y.

OH V

^! 3

(in said formula, Q represents a monovalent hydrocarbon group, optionally substituted having from 1 to 40 carbon atoms, Y ^ Y ₂ and Y ₃ , identical or different, represent a hydrogen atom or a halogen, chlorine atom, fluorine, bromine, iodine and, preferably, fluorine or a perhaloalkyl group having from 1 to 10 carbon atoms and at least one of the groups Y _{1 f} Y ₂ and Y ₃ , represent a halogen atom.

3 - Process according to claim 2 characterized in that the α-halogenated secondary alcohol corresponds to the general formula (I) in which at least two of the groups Y ^ Y ₂ and Y ₃ represent a halogen atom, and again more preferably all the groups Y ^ Y ₂ and Y ₃ represent a halogen atom, preferably a fluorine atom.

4 - Method according to one of claims 2 and 3 characterized in that the α-halogenated secondary alcohol corresponds to the general formula (I) in which Q represents a monovalent hydrocarbon group, substituted or not which may be an aliphatic group acyclic saturated or unsaturated, linear or branched; a saturated, unsaturated or aromatic, monocyclic or polycyclic carbocyclic or heterocyclic group. 5 - Method according to one of claims 2 to 4 characterized in that the α-halogenated secondary alcohol corresponds to the general formula (I) in which Q represents an aryl group corresponding to the general formula (II):

(R)]

(H) in said formula (II):

- n is an integer from 0 to 5, preferably from 0 to 3,

- R represents R- |, one of the following groups or functions:

. an alkyl group, linear or branched, having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl,

. a haloalkyl group having from 1 to 6 carbon atoms, mono-, poly- or perhaloalkyl and from 1 to 13 halogen atoms,. a linear or branched alkenyl group having from 2 to 6 carbon atoms, preferably from 2 to 4 carbon atoms, such as vinyl, allyl,. a linear or branched alkoxy or thioether group having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, groups. a group of formula - OH

- COOH - CHO

- CN

-N- (R ₂ ) ₂ - X

- CF ₃ in said formulas, the groups R ₂ > identical or different, represent a hydrogen atom, a linear or branched alkyl group having from 1 to 6 carbon atoms and even more preferably from 1 to 4 carbon atoms or a phenyl group and X symbolizes a halogen atom, in particular a chlorine or bromine atom, - R represents R3 one of the following more complex groups:

. a group

in which :

R-i has the meaning given above,

R represents a valential bond or a divalent, linear or branched, saturated or unsaturated hydrocarbon group having from 1 to 4 carbon atoms such as, for example, methylene ethylene, propylene, isopropylene, isopropylidene, and m is an integer from 0 to 3,. a group R ₄ - A - R ₅ in which: R ₄ has the meaning given above,

and to one of the following groups: - O -, - CO -, - COO -, - N -, - CO - N -,

IIR ₂ R ₂ in these formulas, m, R- | and R have the meaning given above.

6 - Process according to claim 5 characterized in that the α-halogenated secondary alcohol corresponds to the general formula (I) in which Q represents an aryl group corresponding to the general formula (II) in which n is greater than 1 and the R groups are identical or different and two successive carbon atoms of the benzene ring are linked together by a cetal bridge, preferably by a methylene or extranuclear ethylene group.

7 - Method according to one of claims 5 and 6 characterized in that the α-halogenated secondary alcohol corresponds to the general formula (I) in which Q represents an aryl group corresponding to the general formula (II) in which

- R represents one of the following function groups:. a linear or branched alkyl group having from 1 to 4 carbon atoms,

. a linear or branched alkoxy or thioether group having from 1 to 4 carbon atoms,

. a methylene or ethylene dioxy group,. an -OH group. . a phenyl or benzyl group,

. a halogen atom.

8 - Method according to one of claims 2 to 4 characterized in that the α-halogenated secondary alcohol corresponds to formula (I) in which Q represents a saturated carbocyclic group or comprising 1 or 2 unsaturations in the cycle, having generally from 3 to 7 carbon atoms, preferably 6 carbon atoms in the ring; said cycle can be substituted by 1 to 5 R- groups _| , preferably 1 to 3, R- | having the meanings set out previously in claim 5.

9 - Method according to one of claims 2 to 4 characterized in that the α-halogenated secondary alcohol corresponds to the general formula (I) in which Q represents an alkyl, alkenyl, alkadienyl, alkynyl, linear or branched group having preferably from 1 to 12 carbon atoms; the hydrocarbon chain possibly being:

- interrupted by one of the following groups:

- O -, - CO -, - COO -, - N -, - CO - N -,

I I

R ₂ R ₂ in these formulas R ₂ has the meaning given previously in claim 5,

- and / or carrier of one of the following substituents:

- OH, - COOH, - CHO, - CN, - N (R ₂ ) ₂ , - X, - CF ₃ in these formulas R ₂ has the meaning given previously in claim 5.

10 - Process according to claim 9 characterized in that the α-halogenated secondary alcohol corresponds to the general formula (I) in which Q represents an acyclic aliphatic group, saturated or unsaturated, linear or branched carrying a cyclic substituent, said acyclic aliphatic group being able to be linked to the cycle by a valential bond or by one of the following groups: - O -, - CO -, - COO -, - N -, - CO - N -,

I I

R ₂ R ₂ in these formulas R ₂ has the meaning given previously in claim 5.

11 - Process according to claim 10 characterized in that the α-halogenated secondary alcohol corresponds to the general formula (I) in which Q represents an acyclic aliphatic group, saturated or unsaturated, linear or branched carrying a cycloaliphatic substituent, aromatic or heterocyclic optionally carrying from 1 to 5 identical or different R _{1 f} groups, as defined in claim 5.

12 - Method according to one of claims 2 to 4 characterized in that the α-halogenated secondary alcohol corresponds to the general formula (I) in which Q represents a monovalent heterocyclic group, saturated or not, comprising in particular 5 or 6 atoms in the ring including 1 or 2 heteroatoms such as nitrogen, sulfur and oxygen atoms, the carbon atoms of the heterocycle possibly being substituted, in whole or in part only by groups Rj, R- \ having the meaning given previously in claim 5.

13 - Method according to one of claims 1 to 12 characterized in that the α-halogenated secondary alcohol is 2-hydroxy-1-phenyl-trichloromethylcarbinol, 2-hydroxy-1-phenyl-trifluoromethylcarbinol, 4- hydroxy-1-phenyl- trichloromethylcarbinol, 4-hydroxy-1-phenyl-trifluoromethylcarbinol, 3-hydroxy-4-methoxy-1-phenyl-trichloromethylcarbinol, 3-hydroxy-4-methoxy-1 - phenyl-trifluoromethylcarbinol, 4-hydroxy-3-methoxy-1-phenyl- trichloromethylcarbinol, 4-hydroxy-3-methoxy-1-phenyl-trifluoromethylcarbinol, 3,4-dihydroxy-1 -phenyl-trichloromethylcarbinol, 3,4-dihydroxy-1 -phenyl- trifluoromethylcarbinol, 3,5-dihydroxy-1 -phenyl-trichloromethylcarbinol, 3,5- dihydroxy-1 -phenyl-trifluoromethylcarbinol, 3,5-dihydroxy-4-methyl-1 -phenyl- trichloromethylcarbinol , 5-dihydroxy-4-methyl-1 -phenyl- trifluoromethylcarbinol, 3,4-dimethoxy-1 -phenyl-trifluoromethylcarbinol, 3,4-methylenedioxy-1 -phenyl-trifluoromethylcarbinol, 1, 1, 1-trifluoro-4-octene-2-ol, 1, 1, 1 -trifluoro-4-decene-2-ol.

14 - Method according to claim 1 characterized in that one implements an activator of the metals of group 1b and 8 such as cadmium, cerium, bismuth, lead, silver, tellurium, retain or germanium, preferably bismuth.

15 - Process according to claim 1 characterized in that the catalyst is based on copper, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum or their mixtures: said catalyst being preferably based on platinum and / or palladium.

16 - Process according to claim 15 characterized in that the platinum and / or palladium catalyst is provided in the form of platinum black, palladium black, platinum oxide, palladium oxide or noble metal itself deposited on various supports such as carbon black, calcium carbonate, activated aluminas and silicas or equivalent materials, preferably carbon black.

17 - Process according to claim 1 characterized in that the amount of catalyst to be used, expressed by weight of metal Mj relative to that of the compound of formula (I) can vary from 0.01 to 10% and, from preferably from 0.04 to 2%.

18 - Process according to claim 14 characterized in that the activator is an organic or inorganic derivative of bismuth taken from the group formed by: bismuth oxides; bismuth hydroxides; bismuth or bismuthyl salts of mineral hydracids, preferably chloride, bromide, iodide, sulfide, selenide, tellurium; bismuth or bismuthyl salts of mineral oxyacids, preferably sulfite, sulfate, nitrite, nitrate, phosphite, phosphate; pyrophosphate, carbonate, perchlorate, antimonate, arsenate, selenite, selenate; bismuth or bismuthyl salts of aliphatic or aromatic organic acids, preferably acetate, propionate, salicylate, benzoate, oxalate, tartrate, lactate, citrate; bismuth or bismuthyl phenates, preferably gallate and pyrogallate.

19 - Process according to claim 18 characterized in that the bismuth derivative is taken from the group formed by: the bismuth oxides BÎ2O3 and BÎ2O4; bismuth hydroxide Bi (OH) 3; bismuth chloride BiClβ; bismuth bromide BiBrβ; bismuth iodide BN3; neutral bismuth sulphate ^Bi 2 ^(SO 4) 3 i ^neutral bismuth nitrate Bi (N03) 3, 5H2O; nitrate bismuthyle BiO (Nθ3); bismuthyl carbonate (BiO) 2Cθ3, 0.5 H2O; bismuth acetate Bi (C2H3θ2) 3; bismuthyl salicylate C6H4Cθ2 (BiO) OH.

20 - Method according to claim 14 characterized in that the amount of activator expressed relative to the weight of the metal M- _j engaged varies between 0.1 and

100% and is preferably around 50%.

21 - Process according to claim 1 characterized in that the oxidation is carried out in an aqueous medium containing a basic agent when the α-trihalogenated secondary alcohol of formula (I) is an aromatic compound of formula (I) carrying on the cycle of a halogenomethylcarbinol group and a hydroxyl group.

22 - Process according to claim 21 characterized in that the basic agent is sodium hydroxide.

23 - Process according to claim 21 characterized in that one carries out the salification of the alcohol of formula (I) before the oxidation reaction.

24 - Method according to one of claims 21 to 23 characterized in that one loads the alcohol of formula (I) and the basic agent and the compound is obtained in salified form at room temperature, then l the catalyst based on the metal Mj and optionally the activator are then introduced and the reaction mixture maintained under scanning of oxygen or of a gas containing it is brought to the desired reaction temperature.

25 - Method according to one of claims 21 to 24 characterized in that the oxidation reaction is carried out in a temperature range from 40 ° C to 100 ° C.

26 - Process according to claim 1 characterized in that the oxidation is carried out in an aqueous or organic medium when the α-halogenated secondary alcohol of formula (I) is any α-halogenated secondary alcohol with the exception of aromatic compounds carrying on the cycle of a halogenomethylcarbinol group and a hydroxyl group.

27 - Process according to claim 26 characterized in that the organic solvent is of ester type, preferably butyl acetate. 28 - Process according to claim 26 characterized in that the catalytic entity comprising the metal Mi and the activator is prepared beforehand.

29 - Method according to one of claims 26 to 28 characterized in that the temperature of the oxidation reaction is chosen between 100 ° C and 160 ° C.

30 - Method according to one of claims 26 to 29 characterized in that the compound of formula (I) is charged, water or the organic solvent and the catalytic entity.

31 - α-halogenated ketones corresponding to the general formula:

J. Q - C - C - Y ₂

He I o

^Y 3

(iv) in said formula, Q represents a radical as defined in one of claims 4 to 12 and Y _1} Y ₂ and Y ₃ represent a hydrogen atom or a fluorine atom and Y ₁₅ Y ₂ and Y ₃ represent at least one fluorine atom, preferably three fluorine atoms.

32 - Ketone according to claim 31 characterized in that it corresponds to formula (IV) in which Q represents an aliphatic radical as defined in claim 9 and Y _1s Y ₂ and Y ₃ represent a hydrogen atom or a fluorine atom and Y _1s Y ₂ and Y ₃ represent at least one fluorine atom, preferably three fluorine atoms.

33 - 1, 1, 1-trifluoro-4-octene-2-one,

1, 1, 1 -trifluoro-4-nonene-2-one

1, 1, 1 -trifluoro-4-decene-2-one.

4-trifluoroacétylanisole

4-trifluoroacetyl-2-hydroxy-toluene 2,6-trifluoroacetyl-nonyl-4-phenol

3- (trifluoroacetyl) pyridine