Abstract: Process for converting a chlorinated alkane into at least one less chlorinated alkene by reaction with hydrogen in the presence of a catalyst comprising palladium and a metal selected from the group consisting of silver, gallium, indium, thallium, germanium, tin, lead, arsenic, antimony, bismuth and mixtures thereof.

Abstract: The invention provides a process for hydrotreating an organic feedstock containing a halogenated component and contaminated with distillable oxygen compounds, and/or distillable nitrogen compounds having boiling points lower than the halogenated compounds by means of removing the distillable oxygen compounds and distillable nitrogen compounds with a fractionation zone and then contacting the resulting organic feedstock having a reduced concentration of distillable oxygen and nitrogen compounds and a gaseous recycle stream containing hydrogen with a hydrogenation catalyst in a hydrogenation reaction zone to produce an anhydrous liquid stream comprising hydrogenated hydrocarbonaceous compounds having a reduced concentration of organic halide and a hydrogen halide compound. The resulting effluent from the hydrogenation zone is optionally separated to produce a hydrogenated hydrocarbonaceous stream having a reduced level of halogen and an anhydrous stream comprising a hydrogen halide compound.

Abstract: A novel process for the production of methylenecyclopropane from 3-halogen-2-methyl-1-propene (.beta.-methallyl halogenide) by reacting .beta.-methyallyl halogenides with an alkali metal-bis-(trialkylsilyl)-amide, optionally in the presence of an alkali metal alcoholate and/or a corresponding alcohol. Methylenecyclopropane is obtained in a high yield, combined with a low or negligible amount of 1-methyl-cyclopropene.

Abstract: The durability of a supported noble metal hydrodechlorination catalyst can be improved by (1) treating the supported catalyst, which comprises support and catalytic noble metal, with a non-elemental halide compound, which is not a mineral acid (such as an alkali metal halide, an ammonium halide, an alkaline earth metal halide, and/or a halogenated hydrocarbon); and (2) then using the treated catalyst in a hydrodechlorination reaction. Suitable treatment compounds include ammonium chloride, lithium chloride, or a chlorinated hydrocarbon. The treated catalyst is a novel composition of matter comprising at least one platinum group metal supported by an oxidic support wherein the metal, which is in the zero valent state, predominantly resides adjacent the surface of the support and is predominantly visible under a microscope having a resolution of about 5 .ANG..

Abstract: The present invention provides an efficient process for the production of ethylene or a mixture of ethylene and vinyl chloride, in which some 1,2-dichloroethane (EDC) may also be produced, by reacting chlorine with ethane. The process is characterized by a conversion of ethane per pass through the reactor of at least about 50%, and a combined molar yield of ethylene and vinyl chloride of at least about 80% based on the ethane consumed. In accordance with this invention, there is provided a process for preparing ethylene or a mixture of ethylene and vinyl chloride by the reaction of ethane and chlorine which comprises:(a) providing a stream of ethane feed gas and a stream of chlorine feed gas;(b) preheating either said ethane stream only or both said ethane and chlorine streams;(c) thoroughly mixing said ethane and chlorine feed gases within about one second and at a molar ratio of ethane to chlorine of at least about 0.9:1.

Abstract: A process is provided for the recovery of hydrogen chloride in anhydrous form from a dry (containing less than about 500 parts per million by weight of water) mixture of hydrogen chloride with one or more non-condensable gases and which may also contain components heavier than hydrogen chloride, which process comprises distilling the mixture to produce an overheads stream containing the non-condensable gases and about 95 percent or more by weight of the hydrogen chloride in the mixture and a bottoms stream containing about 95 percent or greater by weight of all components heavier than hydrogen chloride, and compressing and refrigerating the overheads stream whereby a selected proportion of the hydrogen chloride in the overheads stream is produced in a liquid anhydrous form containing less than about 50 parts per million by weight of water.

Abstract: A process for reacting ethane with chlorine to produce a mixture of ethylene and vinyl chloride is disclosed. The process involves the intimate mixing of ethane and chlorine in an ethane to chlorine ratio of at least about 0.9:1 at a temperature such that ethane and chlorine do not react during mixing, and heating the mixture to a temperature above about 215.degree. C. to commence the reaction, allowing the reaction to proceed for a period of less than about 1 minute, and providing sufficient heat to the reacting mixture so that the reacted mixture will have a temperature between about 400.degree. C. and about 800.degree. C.

Abstract: A new hydrodehalogenation catalyst, as well as to its use for the hydrodechlorination of chlorinated hydrocarbons. The hydrodehalogenation catalyst, which converts halogenated hydrocarbons completely under mild conditions, has a considerably longer lifetime than do known catalysts and can be regenerated. In a method of hydrogenating dechlorination the catalyst works preferably under mild reaction conditions, with lifetimes of at least 2,500 hours and leads to reaction products, which can readily be used economically and thermally without further purification. The catalyst is a palladium aluminosilicate support catalyst, which is free of chlorinated compounds, has a palladium content of 0.5 to 8% by weight and a silica content of 1 to 50% by weight. The palladium concentration over the cross section of the support passes through a maximum in the region 50 to 250 .mu.m below the outer surface of the support, the maximum palladium concentration is 1.5 to 7 times the average palladium concentration.

Abstract: Methods for synthesis of chemical compounds by catalytic transfer hydrogenation comprise forming a mixture of a starting material, a hydrogen donor material and a catalyst. The catalyst is selected from a catalytic form of carbon, a polyethylene glycol phase transfer agent, and mixtures thereof. The mixture is heated at a temperature of from 30.degree. to 400.degree. C. in the presence of at least one alkali or alkaline earth metal compound to cause reduction of the starting material by catalytic transfer hydrogenation and form the desired chemical compound product.

Abstract: A crude vinylically unsaturated product formed from a palladium-complex-catalyzed reaction of a reactant halide selected from the group consisting of aryl, allyl, vinyl, and benzyl halides, and a reactant olefin having a vinylic hydrogen, wherein the reaction is carried out in the presence of a hydrogen halide acceptor, is purified by first contacting the crude product with a base that is stronger than the hydrogen halide acceptor, then heating the stronger base-contacted product. The purified product shows a marked reduction in concentration bromine and palladium impurities. The product can then be further purified by such methods as chromatography, crystallization, or distillation to achieve a product that is more suitable for applications where very low levels of inorganic impurities are required.

Abstract: Methods for synthesis of chemical compounds by catalytic transfer hydrogenation comprise forming a mixture of a starting material, a hydrogen donor material and a catalyst. The catalyst is selected from a catalytic form of carbon, a polyethylene glycol phase transfer agent, and mixtures thereof. The mixture is heated at a temperature of from 30.degree. to 400.degree. C. in the presence of at least one alkali or alkaline earth metal compound to cause reduction of the starting material by catalytic transfer hydrogenation and form the desired chemical compound product.

Abstract: A process for converting a chlorinated alkene feedstock including two or more chlorines to reaction products including a less-chlorinated alkene in a commercially substantial proportion, comprising reacting the chlorinated alkene feedstock with hydrogen in the presence of a catalyst consisting essentially of a Group VIII metal other than rhodium, palladium or ruthenium and a Group IB metal on a support.

Abstract: A process for the catalytic conversion of various chlorinated hydrocarbon byproducts and waste products especially to less chlorinated, useful or salable products, in which a chlorinated hydrocarbon feedstock containing two or more chlorines is reacted with hydrogen in the presence of a catalyst consisting essentially of an active hydrogenating metal component such as platinum in elemental or compound form, and a surface segregating metal component such as copper in elemental or compound form on a support.

Abstract: A process for hydrodechlorinating 1,2,3-trichloropropane to produce propylene in preference to propane, comprising reacting 1,2,3-trichloropropane and hydrogen in the presence of a Group VIII metal on carbon catalyst, and especially a platinum on carbon catalyst.

Abstract: A hydrodehalogenation process, comprising the step of reacting a saturated halohydrocarbon (e.g., 1,2-dichloropropane) with hydrogen or a hydrogen donor in the gas phase in the presence of a catalytically effective amount of ruthenium on a support, and at temperatures of at least about 100 degrees Celsius, to produce reaction products including a corresponding non-halogenated, unsaturated hydrocarbon (e.g., propylene).

Abstract: A process for the conversion of a halogenated organic feedstock to produce a stream of hydrocarbonaceous compounds having an exceedingly low concentration of halogenated organic compounds and an aqueous stream containing hydrogen halide.

Abstract: The invention concerns a process for producing unsaturated compounds from chlorinated alkanes by dehydrochlorination wherein a phase transfer catalyst is used during reaction of chlorinated alkane with aqueous base. After dehydrochlorination, the products are distilled or flashed off. Then, the phase transfer catalyst is recovered and reused by extracting the catalyst from spent aqueous base with fresh chlorinated alkane and using the mixture of chlorinated alkane and catalyst from the extraction as feedstock.

Abstract: Preparation of alkenes as well as of cyclopentane and cyclohexane from the corresponding vicinal dichloro and dibromo alkanes and from .alpha.,.omega.-Dichloropentane and .alpha.,.omega.-dibromopentane and .alpha.,.omega.-dichlorohexane and .alpha.,.omega.-dibromohexane respectively, in which these starting compounds are caused to react with with silicon.

Abstract: A novel catalytic process involving complete hydrodehalogenation of halogenated aliphatic hydrocarbons in the presence of a hydrogen donor and a modified zeolite catalyst has been developed. The process is operated in a continuous flow mode and reaction products consist exclusively of hydrogen halide and hydrocarbons. The relative ratio of paraffins to olefins to aromatics obtained in the product distribution is a strong function of the ratio of hydrogen to reactant and the space velocity and temperature employed. The catalyst employed is a nickel metal modified shape selective zeolite that takes advantage of the hydrogenolysis ability of nickel and the acidic-shape selective properties of the zeolite.

Abstract: A process for preparing a vinylically-unsaturated product compound comprises reacting a halogenated organic compound with a hydrolytically-stable, vinylically-unsaturated precursor compound in the presence of (a) a homogeneous zerovalent palladium catalyst complex, (b) an organic hydrogen halide acceptor and (c) a diluent, wherein the diluent is water or an aqueous solution containing up to 95% by volume of an organic solvent. The halogenated organic compound is selected from aryl halides, benzyl halides or vinylic halides. The hydrolytically-stable, vinylically-unsaturated precursor compound is selected from organosilicon compounds, hydrocarbon compounds or compounds containing at least one of an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom or a combination thereof.

Abstract: A process for preparing a vinylically-unsaturated product compound comprises reacting a halogenated organic compound with a hydrolytically-stable, vinylically-unsaturated precursor compound in the presence of (a) a homogeneous zerovalent palladium catalyst complex, (b) an inorganic hydrogen halide acceptor and (c) a diluent, wherein the diluent is water or an aqueous solution containing up to 95% by volume of an organic solvent. The halogenated organic compound is selected from aryl halides, benzyl halides or vinylic halides. The hydrolytically-stable, vinylically-unsaturated precursor compound is selected from hydrocarbon compounds or compounds containing at least one of an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom or a combination thereof.

Abstract: Active methine compounds are chlorinated by contacting such compounds with a perchloroalkane and aqueous base in the presence of a phase transfer catalyst which is an tetraalkylonium hydroxide. Chlorinated products, preferably tertiary alkyl chloro compounds, are produced. The tertiary alkyl chloro compounds are useful in elimination reactions, preferably reactions with base, to form unsaturated compounds, particularly compounds having a vinylidene or exomethylene group.

Abstract: Solid solution catalyst in particulate form consisting of attrition resistant .alpha.-Al.sub.2 0.sub.3 particles with 0.5 to 10% by weight, expressed as the oxide, of iron cations substituted for aluminum cations in said catalyst support stabilized with 0.5 to 10% by weight, expressed as the oxide, of lanthanum and modified with at least two, preferably three, metal cations selected from the metals consisting of chromium, cobalt, magnesium, manganese, and barium; wherein one of said metal cations is barium and said catalyst has X-ray diffraction pattern with peak positions different than that of the .alpha.-Al.sub.2 0.sub.3 structure. A process is disclosed which produces ethylene from ethane while producing reduced amounts of vinyl chloride from said ethane to ethylene process.

Abstract: A process is disclosed which comprises: contacting a catalyst such as alumina silica, aluminosilicates, titanium oxide, magnesium oxide, and the metals of Groups III and IIB of the Periodic Table under reducing conditions with a gaseous mixture comprising elemental chlorine gas and a diluent under conditions effective to improve the ability of the catalyst to dehydrohalogenate halogenated hydrocarbons: contacting the catalyst with a halogenated hydrocarbon feedstock, the halogenated hydrocarbon feedstock with or without a carrier gas, in the gas phase under dehydrohalogenation conditions; and recovering a dehydrohalogenated product.

Abstract: An improved method for detoxifying waste materials contaminated with halogenated hydrocarbons is disclosed. The method achieves dehalogenation of such halogenated hydrocarbons in a manner as efficient as previous methods, but at a considerably lower cost. The economic advantages of the present invention arise from the use of lower temperatures and/or smaller quantities of reagents, which in turn are made possible by the discovery of a surprisingly superior reagent, 2-methoxyethanol.

Abstract: The highly chlorinated methanes, e.g., carbon tetrachloride, are improvedly dechlorinated by reacting same with hydrogen in the presence of oxygen or an oxygen-containing gas, e.g., air, and a catalytically effective amount of a metal of the copper or precious metal Groups of the Periodic Table, typically in the form of a fixed or fluidized bed thereof, and advantageously in the gaseous phase.

Abstract: A process for the halogen-assisted conversion of lower alkanes to higher molecular weight hydrocarbons is provided. A first reaction mixture including lower alkanes, a hydrogen halide and an oxygen-containing gas are contacted with a catalytic composition of crystalline copper aluminum borate at appropriate reaction conditions to form an intermediate composition including halogenated alkanes. The halogenated alkanes are subsequently contacted with a catalytic composition of a pentasil molecular sieve material under appropriate reaction conditions to form a product mixture including hydrocarbons having molecular weights greater than the lower alkanes.

Abstract: A terpene compound having the formula (III) is produced by reacting an allylic halide having the formula (I) with a Grignard reagent having the formula (II) in the presence of anhydrous zinc chloride and a copper compound or an organic zinc halide compound having the formula (IV) in the presence of a copper compound, provided that when A-A is C-C, R' is hydrogen and when A-A is C=C, X is chlorine.

Abstract: A process for the production of a hydrogenated hydrocarbonaceous product from a feedstock comprising organic compounds having a tendency to readily form polymer compounds by means of contacting the feed with a hydrogenated recycle liquid containing dissolved hydrogen in a first hydrogenation reaction zone operated at hydrogenation conditions selected to minimize a hydrogen-rich gaseous phase and to selectively hydrogenate organic compounds having a tendency to readily form polymer compounds and to produce a first hydrogenated stream comprising hydrocarbonaceous compounds and having a reduced concentration of polymer precursors. The resulting first hydrogenated stream is then contacted in a second hydrogenation zone with added hydrogen to produce hydrogenated stream comprising hydrogenated hydrocarbonaceous compounds.

Abstract: An improved method for detoxifying waste materials contaminated with halogenated hydrocarbons is disclosed. The method achieves dehalogenation of such halogenated hydrocarbons in a manner as efficient as previous methods, but at a considerably lower cost. The economic advantages of the present invention arise from the use of lower temperatures and/or smaller quantities of reagents, which in turn are made possible by the discovery of a surprisingly superior reagent, 2-methoxyethanol.

Abstract: In a process for the production of 2,3-dimethylbutenes by the dehydrochlorination of 1-chloro-3,3-dimethylbutane in the presence of a catalyst, a conversion of the starting material and selectivity of the desired product can be improved when at least one compound selected from the group consisting of magnesium compounds, calcium compounds and lanthanum compounds is used as the catalyst.

Abstract: A method for the destruction of halogenated organic compounds contained in a contaminated medium comprises adding an aqueous solution of polyethylene glycol to the contaminated medium in an amount to provide from about 0.1 to about 20 weight percent of polyethylene glycol, based on the weight of the contaminated medium. An alkali metal hydroxide is then added in an amount of from about 2 to about 20 weight percent, based on the weight of the contaminated medium. The medium is then heated to substantially dehydrate the medium and then further heated at a temperature between about 100.degree. and 350.degree. C. to effect destruction of the halogenated organic compounds. An acid is then added to the medium in an amount sufficient to neutralize the same.

Abstract: A method for converting halocarbons, especially lower halocarbons like chloromethane, especially methyl chloride, to hydrocarbons, especially higher molecular weight hydrocarbons, wherein a reaction mixture including the halocarbons is contacted with a borosilicate-containing catalytic composition having a specified composition in terms of mole ratios of oxides and a specified X-ray diffraction pattern to form a product mixture of the desired hydrocarbon(s).

Abstract: Reduction of carbon oxides products in oxidative pyrolysis of halogenated methanes in gas phase halogen-catalyzed oxidative-pyrolytic, non-flame, conversion of methane to higher molecular weight hydrocarbons is carried out in the presence of oxygen-containing gas which is primarily introduced in a latter portion of the process sequence reducing the oxygen requirement for effective suppression of formation of carbonaceous deposits thereby reducing carbon oxides product. Conversion of halogenated methanes to high yields of ethylene by conduct of the reaction in the presence of methane further reduces oxygen requirements and results in insignificant solid carbonaceous deposit formation.

Abstract: A process for the dehydrohalogenation of a feed comprised of an admixture of primary, secondary and tertiary alkylhalides to selectively convert the secondary and tertiary alkylhalides of the admixture to olefins by dehydrohalogenation, with minimal conversion, if any, of the primary alkylhalides. The reaction, which is particularly applicable to the selective dehydrobromination of an admixture of primary, secondary and tertiary alkylbromides, is carried out in a distillation-reaction zone, column, or distillation-reactor, to simultaneously (i) convert the secondary and tertiary alkylbromides to olefins and hydrogen bromide, and (ii) separate the olefins and hydrogen bromide, (iii) and the primary alkyl bromides, from the reaction mixture.

Abstract: Organic halogen compounds in which one or more halogen atoms are covalently bonded to the carbon are subjected to reductive dehalogenation by reaction with a hydrocarbon in the presence of carbon at elevated temperatures with formation of a hydrogen halide, by a process in which the dehalogenation is carried out in the presence of iron powder or an iron compound as a cocatalyst, at from 100.degree. to 450.degree. C.

Abstract: Compositions containing sulfuric acid and one or more of certain chalcogen-containing compounds in which the chalcogen compound/H.sub.2 SO.sub.4 molar ratio is below 2 contain the mono-adduct of sulfuric acid which is catalytically active for promoting organic chemical reactions. Suitable chalcogen-containing compounds have the empirical formula ##STR1## wherein X is a chalcogen, each of R.sub.1 and R.sub.2 is independently selected from hydrogen, NR.sub.3 R.sub.4, and NR.sub.5, at least one of R.sub.1 and R.sub.2 is other than hydrogen, each of R.sub.3 and R.sub.4 is hydrogen or a monovalent organic radical, and R.sub.5 is a divalent organic radical. Such compositions are useful for catalyzing organic reactions such as oxidation, oxidative addition, reduction, reductive addition, esterification, transesterification, hydrogenation, isomerication (including racemization of optical isomers), alkylation, polymerization, demetallization of organometallics, nitration, Friedel-Crafts reactions, and hydrolysis.

Abstract: A process for converting a feedstock containing 1 to about 6 carbon atoms per molecule which includes (a) contacting the feedstock with a solid composition comprising a crystalline microporous three dimensional solid catalyst having pores and being capable of promoting the conversion, and matrix material at conditions effective to convert the feedstock, to produce at least one desired product, and to at least partially deactivate the solid composition; (b) contacting the deactivated solid composition with regeneration medium at conditions to at least partially regenerate the solid composition; and (c) repeating step (a), the improvement which comprises (d) contacting the regenerated solid composition prior to step (c) to condition the regenerated solid composition to have increased effectiveness in step (c).

Abstract: A process for the preparation of olefins by the elimination of hydrogen halide from tertiary alkyl halides, the reaction being carried out by heating the alkyl halide in water to from 40.degree. to 130.degree. C. and simultaneously distilling off from the reaction mixture the olefins formed.

Abstract: Natural gas components are converted to unsaturated hydrocarbons and hydrogen, as by a one-step process. The reaction products comprise a mixture containing hydrogen, acetylene, ethylene, propylene, C.sub.4 species, aromatics, hydrogen chloride, etc. Acetylene and ethylene are separated from this mixture as main products; and hydrogen chloride is converted to chlorine for recycle.

Abstract: A process for the preparation of cis-9-tricosene is disclosed. Cis-1,9-octadecadiene, which may be obtained by the dehydration of oleyl alcohol, is metallated with an organomagnesium halide, producing cis-9-octadecenylmagnesium halide, which in turn is alkylated with n-pentyl halide to form the desired cis-9-tricosene.

Abstract: A process for oxidative pyrolysis of halogenated methanes in the presence of oxygen-containing gas under non-flame conditions is provided whereby the formation of solid carbonaceous materials is significantly reduced, while high yields of desired higher molecular weight hydrocarbons such as acetylene and ethylene are maintained.

Abstract: A process for dehalogenating halogenated organic compounds comprising:(1) combining in an electrochemical cell(a)(i) a halogenated organic compound or (ii) a solid or fluid containing a halogenated organic compound with(b) a compound capable of forming an iminium ion having the formula (I) ##STR1## wherein X represents an oxygen atom or a sulfur atom,R.sub.1 and R.sub.2, which may be the same or different, each represents an alkyl group, an aryl group or a heterocyclic group, and R.sub.1 and R.sub.2 may combine and form a carbocyclic ring or a heterocyclic ring, andR.sub.3 represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group or a halogen atom, and(2) applying an electrical voltage and an electrical current to an electrode of the electrochemical cell as a working electrode; which voltage is such that a reaction occurs and the halogenated organic compound is partially or completely dehalogenated.

Abstract: Method for the total dehydrohalogenation of halogenated compounds. The method includes providing a reaction mixture by dissolving an alkali metal hydroxide in a molar excess of an ethylene glycol to form an alkali metal glycolate and reacting the halogenated organic compound with the alkali metal glycolate. In halogenated compounds having one carbon, carbon dioxide is the reaction product. In those having more than one carbon, acetylene is formed. The preferred ethylene glycol is tetraethylene glycol and the preferred alkali metal is potassium hydroxide. The method is particularly useful for disposing of toxic halogenated compounds which make up soil contaminants, like ethylene dibromide.

Abstract: A monohalomethane is converted to a product comprising hydrocarbons having at least 2 carbon atoms and in particular aliphatic hydrocarbons in the gasoline boiling range by contact with a synthetic crystalline gallosilicate zeolite loaded either with at least one modifying cation selected from hydrogen and metals of Groups I to VIII of the Periodic Table or with a compound of at least one Group I to VIII metal.

Abstract: For the production of 3,3- and 2,3-dimethylbutene, respectively, and 2,3-dimethylbutadiene and/or for the simultaneous production of 3,3- and 2,3-dimethylbutene, respectively, 2,3-dimethylbutadiene, and glycol or polyglycol n-alkyl-3,3- and -2,3-dimethylbutyl ether, respectively, alkali hydroxides are reacted in a two-phase liquid system in the presence of a glycol or polyglycol ether, respectively, at temperatures of 100.degree.-250.degree. C., with mono- and dichlorodimethylbutane, respectively. By using, as the glycol or polyglycol ether, a glycol or polyglycol monoalkyl ether, the glycol or polyglycol n-alkyl-3,3- and -2,3-dimethylbutyl ether, respectively, is obtained besides the olefin.

Abstract: MTBE can be dissociated with high selectivity to isobutene and methanol over acid action exchange resin catalysts using very high LHSV, e.g. of 7 to 35 at pressure drops of 0.5 to 50 psig through the fixed bed at reaction pressure of 0.5 to 4 atmospheres and bed temperatures in a fixed bed tubular-reactor in the range of 90.degree. C. to 160.degree. C. Good conversions are obtained and undissociated MTBE and by-products of the dissociation may be recycled to a liquid phase MTBE synthesis.

Abstract: The new tetraene of formula: ##STR1## is useful particularly as an intermediate in the synthesis of, for example, hexahydropseudoionone, pseudoionone and vitamin A.It may be made by dehydrochlorinating 3-chloro-2-methyl-6-methylene-1,3,7-octadiene in the presence of a palladium catalyst and an inorganic base.

Abstract: This invention discloses a process for converting heterosubstituted methanes, such as methyl alcohol, methyl ether, methyl mercaptan, dimethyl sulfide, methyl halides, methylal, methylamine and the like, by contacting such methanes with bifunctional acid-base catalysts at elevated temperatures, between 200.degree. and 450.degree. C., preferably between 250.degree. and 375.degree. C., to produce predominantly lower olefins, preferably ethylene and propylene. The catalysts of preference are those derived from halides, oxyhalides, oxides, sulfides or oxysulfides of transition metals of Groups IV, V, VI, VIII of the Periodic Table, such as tantalum, niobium, zirconium, tungsten, titanium, chromium and the like, deposited on acidic oxides and sulfides such as alumina, silica, zirconia or silica-alumina.

Abstract: Styryl-cyclopropane derivatives of the formula ##STR1## in which R.sup.9 represents independently of one another when n=2, halogen, cyano, nitro, or an optionally halogen-substituted alkyl, alkoxy, alkylthio or alkylenedioxy radical,n represents zero, 1, 2, 3, 4 or 5,R.sup.10 represents hydrogen or halogenandY represents acetyl, cyano or carbamoyl, are produced by reacting a benzylphosphonic acid ester of the formula ##STR2## in which R.sup.4 each independently represents alkyl or phenyl or together represent alkylene, with a formylcyclopropane derivative of the formula ##STR3## or by reacting an .alpha.-hydroxyphosphonic acid ester of the formula ##STR4## with an olefinating agent of the formula ##STR5## in which Z' represents a phosphorus-containing radical ##STR6## wherein R.sup.5 and R.sup.6 are identical or different and individually represent alkyl, phenyl, alkoxy or pehnoxy or R.sup.5 and R.sup.6 together represent alkanedioxy,R.sup.