Solvay Fluor Und Derivate Gmbh

Solvay Fluor Gmbh

Solvaytflour Und Derivate Gmbh

Kerstin Eichholz

Max Josef Braun

Werner Rudolph

Stefan Palsherm

Francine Janssens

Johannes Eicher

Carsten Brosch

Matthias Rieland

Francine Jannssens

A method of producing alkanes containing chlorine by addition of chlorine to C&#x2014;C double bonds or C&#x2014;C triple bonds or by exchange of hydrogen for chlorine by contacting the starting compound in the gas or liquid phase with elemental chlorine and irradiating the reaction mixture with UV light having a wavelength of &#x3bb;&#x2267;280 nm. In this way pentachloroethane can be produced from trichloroethylene, CFC-113 from HCFC-123 or HFC-133a, CFC-112a from HCFC-142b, or HCFC-123 from HCFC-133a. The method also is suitable for separating photochlorinatable impurities from HFC-365-mfc to obtain purified HFC-365-mfc. Advantages include high yields and excellent selectivity.

UV-activated chlorination process

Acid fluorides, for example carboxylic acid fluorides and sulfuryl fluoride are produced by reacting the corresponding acid chlorides with hydrogen fluoride adducts of ammonium fluoride or amine hydrofluorides (which act as a catalyst or as a fluorination agent). Consumed HF adducts may be regenerated with HF.

Method of producing acid fluorides from acid chlorides

The methyl and ethyl esters of trifluoroacetic acid or chlorodifluoroacetic acid can be prepared in a technically simple manner from the corresponding acid chlorides and methanol or ethanol, respectively, in the presence of an &ldquo;onium&rdquo; salt of the acid as a catalyst. The alcohol is used in a stoichiometric excess, namely the molar ratio of alcohol to acid chloride is selected such that operation is in the region of a two-phase reaction. One of the phases is formed by the desired ester product, which is obtained in a high purity without any distillation.

Two phase preparation of carboxylic acid esters

An improved process for preparing carboxylic acid esters from acid chlorides, acid bromides or acids and alcohols provides for performing the esterification in the presence of the adduct (onium salt) of the corresponding carboxylic acid and 1,5-diazabicyclo&lsqb;4.3.0&rsqb;-non-2-ene or 1,8-diazabicyclo&lsqb;5.4.0&rsqb;-undec-7-ene. Alternatively, it is possible to operate in the presence of the corresponding carboxylic acid and an onium salt of the corresponding carboxylic acid.

Process for preparing esters

A method for producing carboxylic acid fluorides of the formula RCFXC(O)F, where X represents fluorine or chlorine, in good yields and with good selectivity for the carboxylic acid fluorides by reacting compounds of the formula RCFXCHFCl with oxygen by photochemical oxidation in the gaseous phase, preferably under sensitization with chlorine and using light having a wavelength &lgr;&gE;280 nm, which conditions make it possible to work without the use of pressure. Glass apparatus may be covered with a protective coating so as to protect it against traces of hydrogen fluoride. To this end, for example, heat-shrinkable sleeves made of light-permeable hydrogen fluoride-resistant material may be used. Polytetrafluoroethylene, polyfluoropropylene or a mixture thereof are especially suitable for this purpose. This type of protection is also suitable for other reactions such as photo-induced fluoro-dediazonation in hydrogen fluoride/pyridine for the production of aromatic compounds fluorinated in the nucleus or the oxidation of CHCl groups for the production of carboxylic acid chlorides.

Production of carboxylic acid fluorides

Lower alkyl esters of 3-amino crotonates substituted by halogen in the C-4 position, e.g. ethyl 3-amino-4,4,4-trifluoro-crotonate, in which the amino group optionally may be substituted by one or two C1 to C3 alkyl groups or by one or two aryl groups, e.g. phenyl, are synthesized by thermolysis of ammonium salts of corresponding lower alkyl esters of acetoacetic acid substituted in the C-4 position by halogen, and removal of the resulting water of reaction. The water of reaction may be removed by an entraining agent, which preferably has a specific gravity heavier than that of the aqueous phase which forms in the reaction. This minimizes yield losses due to the ammonium salt becoming dissolved in the aqueous phase and results in especially high yields. Formation of the ammonium salt and thermolysis can be carried out simultaneously. Alternatively, it is possible to start from a molten ammonium salt of the halogencrotonate, e.g. the salt of the lower alkyl ester of 4,4,4-trifluoroacetoacetic acid, or to produce the salt in situ, and to pass an inert gas through the molten salt under thermolytic conditions and in the absence of a solvent. In this way the desired product can be produced in high yield and in high purity. This alternative can be implemented as a continuous process.

Production of aminohalogencrotonates

Organic compounds, e.g. fluorinated organic compounds such as fluorinated carboxylic acids or fluorinated carboxylic acid chlorides, may contain small amounts of carboxylic acid fluorides, hydrogen fluoride or hydrolyzable fluoride, which during the preparation of derivatives of the fluorinated organic compounds, for example by esterification, may yield corrosive fluorides or hydrogen fluoride. The invention is a method for the synthesis and/or purification of preferably fluorinated organic compounds such as carboxylic acids, carboxylic acid chlorides and derivatives such as esters thereof, starting from corresponding carboxylic acid chlorides containing acid fluorides or hydrolyzable fluoride, and alcohols under the catalytic action of &ldquo;onium&rdquo; salts of carboxylic acids, to obtain products which have a low fluoride content. Alternatively, an inorganic oxide adsorbent is utilized. The method is especially suitable for the synthesis of esters of trifluoroacetic acid, chlorodifluoroacetic acid, trifluoroacetoacetic acid and/or difluoroacetoacetic acid.

Synthesis of low-fluoride organic compounds

Difluorochloracetyl, dichloracetyl and trichloracetyl chloride

A process for preparing polyfluorochloro- and perfluorocarbonyl chlorides, for example for preparing perfluoropropionyl chloride, chlorodifluoroacetyl chloride or trifluoroacetyl chloride, in which starting materials are employed which have a CHCl.sub.2 group which is converted to a C(O)Cl group by photochemical oxidation with oxygen in the presence of added elemental chlorine and under exposure to activating irradiation by light having a wavelength .lambda..gtoreq.290 nm. The procedure is preferably unpressurized. Outstanding conversions with high selectivity are achieved using doped Hg light sources.

Process for preparing polyfluorochlorocarbonyl chlorides and

A process for preparing compounds corresponding to the formula RCFXC(O)Cl, in which X is fluorine or chlorine and R is fluorine or a perfluorinated C1- C10-alkyl group, preferably chlorodifluoroacetyl chloride, by photochemical oxidation of R122 (CF.sub.2 ClCHCl.sub.2) and the preparation of trifluoroacetyl chloride by photochemical oxidation of R123 (CF.sub.3 CHCl.sub.2) with oxygen under irradiation. The reaction is preferably carried out without pressurization and without addition of elemental chlorine.

Process for preparing polyfluorocarboxylic acid chlorides and

A process for preparing carboxylic acid halides and carboxylate salts by reacting metal or 'onium' halides with carboxylic anhydrides, which process is very suitable for working-up anhydrous, spent catalyst preparations. The resulting carboxylic acid halide or carboxylate salt can be used as an acylating reagent or alkylating reagent, and metal halide or 'onium' halide liberated during this can be reacted anew with carboxylic anhydride and regenerated, thereby making it possible to effect a hydrolysis-free alkylation or acylation without forming salt-type waste products. If the mixture of carboxylic acid halide and carboxylate salt is allowed to react with an alcohol, preferably in situ, the resulting ester can be isolated without hydrolysis.

Production of carboxylic acid halides and carboxylate salts

A process for preparing ketones, for example CF.sub.3 C(O)CH.sub.3, CF.sub.3 C(O)CH.sub.2 C(O)CF.sub.3 and CF.sub.3 C(O)CF.sub.2 H, in which .beta.-ketoesters are transesterified and decarboxylated using a carboxylic acid, for example trifluoroacetic acid, in the presence of a catalyst, particularly an 'onium' salt of a carboxylic acid or an effective amount of a proton-donating acid, preferably a sulfonic acid such as alkyl- or arylsulfonic acids, or a mineral acid. The process is advantageously carried out in the absence of water, so that no formation of acetals or hydrates occurs, and no dehydrating step is needed. The process is simple to carry out, and if transesterification is carried out with a sufficiently active carboxylic acid, for example with trifluoroacetic acid, the presence of an additional catalyst is unnecessary.

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Langenhagen, Germany

Kerstin Eichholz