Chemistry: electrical and wave energy – Processes and products – Processes of treating materials by wave energy
Patent
1997-11-06
2000-12-05
Gorgos, Kathryn
Chemistry: electrical and wave energy
Processes and products
Processes of treating materials by wave energy
20415776, 20415778, 20415779, 2041578, 20415794, 20415811, 20415812, 25218311, 252600, 570171, 570175, 588230, 588250, C07F 100, C07C 1700, C07C 1726, C09K 300
Patent
active
061561630
DESCRIPTION:
BRIEF SUMMARY
This application is an application under 35 U.S.C. Section 371 of International Application No. PCT/FR96/00264, filed on Feb. 19, 1996.
The present invention relates to a perfluoroalkylation technique and especially a reactant, a compound and a process for the perfluoroalkylation of a nucleophile, and to the derivatives thus obtained. It relates more particularly to the use of the homolytic scission of certain chalcogen esters with relatively heavy chalcogens, that is to say of an atomic row at least equal to that of sulphur.
Thus, the field of the invention is that of the synthesis of compounds which are perhaloalkylated and/or acylated; at least partially organic and of various kinds, the said radicals being supplied by perhaloalkylating and/or acylating agents,
The present invention also relates to a process for obtaining perhalogenated, in particular perhaloalkylated and/or acylated compounds and to perhaloalkylated and/or acylated thioethers.
The halogen considered more precisely but without any limitation being implied is fluorine, because of the great interest which exists in employing it is a substituent in many industrial products such as colorants, polymers and pharmaceutical and agrochemical compounds. It is well known, in fact, that fluorine is an inducer of lipophilicity in biologically active molecules.
Moreover its electronegativity and its relatively small size are positive factors in relation to: polymers, molecules.
Bearing in mind the scientific and technical interest of the trifluoromethyl substituent, especially in the pharmaceutical and the agrochemical fields, many methods of trifluoromethylation have already been proposed.
Among these, direct trifluoromethylation according to an electrophilic, nucleophilic and/or radical mechanism is that most worthy of interest from the technical and industrial standpoint.
Techniques for trifluoromethylation by a radical have the advantage of often making it possible to operate in very mild conditions.
To be sure, using this route, the perfluoroalkylation with the aid of perfluoroalkyl iodides such as CF.sub.3 I is known. These compounds react with various substrates thermally, under irradiation or in the presence of a catalytic quantity of a radical initiator such as benzoyl peroxide or azobisiobutyronitrile (AIBN). Perfluoroalkyl iodides are costly products and rarely available on an industrial scale.
Moreover, the reactions involved are liable to give rise, as by-products, to iodine-containing products known to be toxic, of the CF.sub.3 --CH.sub.2 --CH.sub.2 --I type.
Derivatives of perfluoroalkanesulphonic acids which are also suitable for a radical route are themselves also costly and still rarely available on an industrial scale.
Nitrosotrifluoromethane derivatives can also be employed, but suffer from the disadvantage of being toxic and hazardous to synthesize.
Perfluoroalkanoic acids and their derivatives, such as trifluoroacetic acid, could possibly have been employed as perhaloalkylating agents. It has been found, however, that they are difficult to convert into the .CF.sub.3 radical. The electrochemical oxidation used for this purpose requires, in fact, very high voltages and large excesses of this reactant. The industrial feasibility of the process involving these compounds is therefore not established.
Trifluoromethanethiol (CF.sub.3 SH) and trifluoromethanesulphenyl chloride CF.sub.3 SCl are known as being reactive agents for trifluoromethylthioalation. However, they have the disadvantage of being gaseous and highly toxic.
In practice, the most common trifluoromethylating agent is bromotrifluoromethane (CF.sub.3 Br). This industrial product is employed a fire-extinguishing agent, especially in aircraft and computer rooms. It is at present one of the largest sources of trifluoromethyl radicals.
CF.sub.3 Br can be reduced monoelectronically to give .CF.sub.3, a radical capable of being trapped, either by nucleophilic substrates, reducing agents and initiators, such as thiolates, thiophenates, selenophenates, stabilized carbanions or ena
REFERENCES:
Brookes et al., "Reactions of Fluoroalkyl Radicals Generated Electrochemically. Part I. Additions of Trifluoromethyl Radicals to Olefinic and Acetylenic Bonds", J. Chem. Soc., No. 3, pp. 202-209, 1978.
Clavel et al., "Trifluoromethylation of Organic Disulphides With Sodium Trifluoromethane-Sulphinate Under Oxidative Conditions: Synthesis of Trifluoromethyl Thioethers", Phosphorus, Sulfur, Silicon and the Related Elements, vol. 59, Nos. 1-4, pp. 169-172, 1991.
Bock et al., "Study of d-Orbital Effects in Esters of Trifluorothiolacetic Acid. A Comparison of Evidence From Dipole Moment and Kinetic Data", Can. J. Chem., vol. 52, No. 17, pp. 3113-3118, Sep. 1974.
Weeks et al., "Chemistry of Trifluorothiolacetic Acid and Its Derivatives. II", J. Fluorine Chem., vol. 1, No. 3, pp. 295-307, Jan. 1972.
Haszeldine et al., "The Reactions of N,N-bistrifluoromethylaminotrifluoromethanesulphonate With Nucleophiles", J. Fluorine Chem., vol. 8, No. 1, pp. 101-104, 1976.
DeMarco et al., "Reactions of the Difluoroamine-Potassium Fluoride Adduct, HNF2.KF, With Sulphinyl and Perfluoroalkylsulphinylfluorides. Preparation of Perfluoroalkyl Perfluoroalkylsulphinates", Inorg. Chem., vol. 12, No. 8, pp. 1896-1899, Aug. 1973.
Bzhezovskii et al., "13C NMR and X-ray Fluorescence Spectra of a Series of Benzyl Sulphides", Bull. of the Academy of Sci. of the USSR, vol. 34, No. 6, Part 2, pp. 1281-1283, Jun. 1985.
Nguyen et al., "Perfluorothioalkanoyl Halides. Preparation From Sulphides", J. Fluorine Chem., vol. 35, No. 3, pp. 523-530, Mar. 1987.
Forat Gerard
Langlois Bernard
Roques Nicolas
Tordeux Marc
Wakselman Claude
Gorgos Kathryn
Rhodia Chimie
Seugnet Jean-Louis
Wong Edna
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