Abstract: This invention describes processes to make products by cross metathesis of functionalized or non-functionalized olefins with poly-branched poly-olefins such as terpenes (e.g., farnesene(s), ?-farnesene, ?-farnesene, ?-myrcene, etc.) and compositions made by such methods.

Abstract: The present invention relates to compositions comprising alkene benzenes or alkene benzene sulfonates or alkylbenzenes or alkylbenzene sulfonates; methods for making alkene benzenes or alkene benzene sulfonates or alkylbenzenes or alkylbenzene sulfonates; where the benzene ring is optionally substituted with one or more groups designated R*, where R* is defined herein. More particularly, the present invention relates to compositions comprising 2-phenyl linear alkene benzenes or 2-phenyl linear alkene benzene sulfonates or 2-phenyl linear alkylbenzenes or 2-phenyl linear alkylbenzene sulfonates; methods for making 2-phenyl alkene benzenes or 2-phenyl alkene benzene sulfonates or 2-phenyl alkylbenzenes or 2-phenyl alkylbenzene sulfonates; where the benzene ring is optionally substituted with one or more groups designated R*, where R* is defined herein.

Abstract: A method for the oxidative coupling of hydrocarbons, such as the oxidative coupling of methane to toluene, includes providing an oxidative catalyst inside a reactor, and carrying out the oxidative coupling reaction under a set of reaction conditions. The oxidative catalyst includes (A) at least one element selected from the group consisting of the Lanthanoid group, Mg, Ca, and the elements of Group 4 of the periodic table (Ti, Zr, and Hf); (B) at least one element selected from the group consisting of the Group 1 elements of Li, Na, K, Rb, Cs, and the elements of Group 3 (including La and Ac) and Groups 5-15 of the periodic table; (C) at least one element selected from the group consisting of the Group 1 elements of Li, Na, K, Rb, Cs, and the elements Ca, Sr, and Ba; and (D) oxygen.

Abstract: A method for the oxidative coupling of hydrocarbons, such as the oxidative coupling of methane to toluene, includes providing an oxidative catalyst inside a reactor, and carrying out the oxidative coupling reaction under a set of reaction conditions. The oxidative catalyst includes (A) at least one element selected from the group consisting of the Lanthanoid group, Mg, Ca, and the elements of Group 4 of the periodic table (Ti, Zr, and Hf); (B) at least one element selected from the group consisting of the Group 1 elements of Li, Na, K, Rb, Cs, and the elements of Group 3 (including La and Ac) and Groups 5-15 of the periodic table; (C) at least one element selected from the group consisting of the Group 1 elements of Li, Na, K, Rb, Cs, and the elements Ca, Sr, and Ba; and (D) oxygen.

Abstract: A method for the oxidative coupling of hydrocarbons, such as the oxidative coupling of methane to toluene, includes providing an oxidative catalyst inside a reactor, and carrying out the oxidative coupling reaction under a set of reaction conditions. The oxidative catalyst includes (A) at least one element selected from the group consisting of the Lanthanoid group, Mg, Ca, and the elements of Group 4 of the periodic table (Ti, Zr, and Hf); (B) at least one element selected from the group consisting of the Group 1 elements of Li, Na, K, Rb, Cs, and the elements of Group 3 (including La and Ac) and Groups 5-15 of the periodic table; (C) at least one element selected from the group consisting of the Group 1 elements of Li, Na, K, Rb, Cs, and the elements Ca, Sr, and Ba; and (D) oxygen.

Abstract: Disclosed herein are processes in which precipitation permits removal of metal halides (e.g. AlCl3) from ionic liquids. After precipitation, the precipitated metal halides can be physically separated from the bulk ionic liquid. More effective precipitation can be achieved through cooling or the combination of cooling and the provision of metal halide seed crystals. The ionic liquids can be regenerated ionic liquid catalysts, which contain excess metal halides after regeneration. Upon removal of the excess metal halides, they can be reused in processes using ionic liquid catalysts, such as alkylation processes.

Abstract: A method for the oxidative coupling of hydrocarbons, such as the oxidative coupling of methane to toluene, includes providing an oxidative catalyst inside a reactor, and carrying out the oxidative coupling reaction under a set of reaction conditions. The oxidative catalyst includes (A) at least one element selected from the group consisting of the Lanthanoid group, Mg, Ca, and the elements of Group 4 of the periodic table (Ti, Zr, and Hf); (B) at least one element selected from the group consisting of the Group 1 elements of Li, Na, K, Rb, Cs, and the elements of Group 3 (including La and Ac) and Groups 5-15 of the periodic table; (C) at least one element selected from the group consisting of the Group 1 elements of Li, Na, K, Rb, Cs, and the elements Ca, Sr, and Ba; and (D) oxygen.

Abstract: A method for the oxidative coupling of hydrocarbons, such as the oxidative coupling of methane to toluene, includes providing an oxidative catalyst inside a reactor, and carrying out the oxidative coupling reaction under a set of reaction conditions. The oxidative catalyst includes (A) at least one element selected from the group consisting of the Lanthanoid group, Mg, Ca, and the elements of Group 4 of the periodic table (Ti, Zr, and Hf); (B) at least one element selected from the group consisting of the Group 1 elements of Li, Na, K, Rb, Cs, and the elements of Group 3 (including La and Ac) and Groups 5-15 of the periodic table; (C) at least one element selected from the group consisting of the Group 1 elements of Li, Na, K, Rb, Cs, and the elements Ca, Sr, and Ba; and (D) oxygen.

Abstract: A method for the oxidative coupling of hydrocarbons includes providing an oxidative catalyst inside a reactor and carrying out the oxidative coupling reaction under a set of reaction conditions. The reactor surfaces that contact the reactants and products do not provide a significant detrimental catalyzing effect. In an embodiment the reactor contains an inert lining or a portion of the reactor inner surface is treated to reduce the detrimental catalytic effects. In an embodiment the reactor contains a lining that includes an oxidative catalyst.

Abstract: A method for the production of styrene comprising reacting toluene and syngas in one or more reactors is disclosed.

Abstract: A process for alkylating aromatic compounds using a family of zeolites, examples of which have been designated UZM-5, UZM-5P and UZM-6, and are represented by the empirical formula: Mmn+Cgh+Rrp+Al(1-x)ExSiyOz where M is an alkali or alkaline earth metal, E is an optional framework element, C organic nitrogen containing cation template, and R is an organic cation crystallization template. The zeolites have at least two x-ray diffraction peaks, one at a d-spacing of 3.9±0.12 ? and one at a d-spacing 8.6±0.20 ?; a tetragonal unit cell; and a micropore volume ranging from about 0.10 cc/g to about 0.18 cc/g.

Abstract: A method of making a catalyst containing nanosize zeolite particles supported on a support material is disclosed. A process for making styrene or ethylbenzene by reacting toluene with a C1 source over a catalyst containing nanosize zeolite particles supported on a support material is disclosed.

Abstract: A process for alkylating aromatic compounds using a family of zeolites, examples of which have been designated UZM-5, UZM-5P and UZM-6, and are represented by the empirical formula: Mmn+Cgh+Rrp+Al(1-x)ExSiyOz where M is an alkali or alkaline earth metal, E is an optional framework element, C organic nitrogen containing cation template, and R is an organic cation crystallization template. The zeolites have at least two x-ray diffraction peaks, one at a d-spacing of 3.9±0.12 ? and one at a d-spacing 8.6±0.20 ?; a tetragonal unit cell; and a micropore volume ranging from about 0.10 cc/g to about 0.18 cc/g.

Abstract: A method for the production of styrene comprising reacting toluene and syngas in one or more reactors is disclosed.

Abstract: A method is disclosed of preparing a catalyst, including contacting a substrate with at least one solution including a first promoter being Cs and at least one solution including a second promoter. The contact subjects the substrate to the addition of the first and second promoters, thereby forming the catalyst comprising the first and second promoters. In the method disclosed, the second promoter is capable of undergoing a redox reaction.

Abstract: A method is disclosed of preparing a catalyst including providing a substrate and a first solution containing at least one promoter, contacting the substrate with the solution to obtain a catalyst containing at least one promoter, wherein the contacting of the substrate with the solution subjects the substrate to the addition of at least one promoter.

Abstract: A method for the production of styrene comprising reacting toluene and syngas in one or more reactors is disclosed.

Abstract: Styrene production processes and catalysts for use therein are described herein. The process generally includes providing a C1 source; contacting the C1 source with toluene in the presence of a catalyst disposed within a reactor to form a product stream including ethylbenzene, wherein the catalyst includes a nanocrystalline zeolite; and recovering the product stream from the reactor.

Abstract: A light olefin feed for an olefin conversion process is subjected to a water wash to remove water-soluble contaminants after which the water is separated from the olefin prior to the conversion reaction. The water used for the wash is free of boiler feedwater additives, especially basic nitrogenous additives, which adversely affect catalytic function.

Abstract: The invention relates to a process of reacting a primary allylic alcohol with a compound containing a) a metal selected from the group consisting of Ag, Au, Ce, Mn, Ni, Ru, Re, Zn and Co preferably Ag and b) an oxidant like TEMPO (2,2?,6,6?-tetra-methylpiperidin-1-oxyl) or its derivates and c) a co-oxidants selected from the group of peroxodisulfates (PDS), H2505, H2O2, NaOCl, O2, KOCl, and air.

Abstract: A process for preparing an organic hydroperoxide, which process comprises: (a) oxidizing an organic compound to obtain an organic reaction product containing organic hydroperoxide; (b) mixing at least part of the organic reaction product of step (a) with a basic aqueous solution to obtain a mixture of basic aqueous solution and the organic reaction product; (c) separating the mixture of step (b) to obtain a separated organic phase containing organic hydroperoxide, and a separated aqueous phase; (d) mixing at least part of the separated organic phase of step (c) with water to obtain a mixture of an aqueous phase and the organic phase; and (e) separating the mixture of step (d) to obtain a separated organic phase containing organic hydroperoxide, and a separated aqueous phase; in which process the separation to a separated organic phase and a separated aqueous phase in step (e) is carried out with the help of a coalescer containing glass fibers.

Abstract: A method for the oxidative coupling of hydrocarbons, such as the oxidative coupling of methane to toluene, includes providing an oxidative catalyst inside a reactor, and carrying out the oxidative coupling reaction under a set of reaction conditions. The oxidative catalyst includes (A) at least one element selected from the group consisting of the Lanthanoid group, Mg, Ca, and the elements of Group 4 of the periodic table (Ti, Zr, and Hf); (B) at least one element selected from the group consisting of the Group 1 elements of Li, Na, K, Rb, Cs, and the elements of Group 3 (including La and Ac) and Groups 5-15 of the periodic table; (C) at least one element selected from the group consisting of the Group 1 elements of Li, Na, K, Rb, Cs, and the elements Ca, Sr, and Ba; and (D) oxygen.

Abstract: Disclosed are novel metathesis catalysts of the formula wherein R1, R2, R3, R4, R5, R6, X1, X2, L and Y are as described herein, a process for making the same and their use in metathesis reactions such as ring closing or cross metathesis.

Abstract: The invention relates to novel carbene ligands and their incorporated monomeric and resin/polymer linked ruthenium catalysts, which are recyclable and highly active for olefin metathesis reactions. It is disclosed that significant electronic effect of different substituted 2-alkoxybenzylidene ligands on the catalytic activity and stability of corresponding carbene ruthenium complexes, some of novel ruthenium complexes in the invention can be broadly used as catalysts highly efficient for olefin metathesis reactions, particularly in ring-closing (RCM), ring-opening (ROM), ring-opening metathesis polymerization (ROMP) and cross metathesis (CM) in high yield. The invention also relates to preparation of new ruthenium complexes and the use in metathesis.

Abstract: A method for the production of styrene comprising reacting toluene and syngas in one or more reactors is disclosed.

Abstract: Provided are a plasticizer composition including a hydroxypivalyl hydroxypivalate ester and a neopentylglycol ester, and a method of preparing the plasticizer composition. The plasticizer composition provides a polyvinyl chloride resin having excellent properties of heat loss, migration resistance and plasticization efficiency, and tensile strength, elongation, etc.

Abstract: Methods are described for the simultaneous dehydrogenation of ethylbenzene and ethane in the presence of oxygen or carbon dioxide via a mixed metal oxide (MMO) catalyst or lithium-promoted sulfated zirconia catalyst to prepare styrene monomer from benzene and ethane. An alkylation unit produces ethyl benzene from ethylene and benzene, and an oxydehydrogenation unit produces styrene and ethylene from ethane, ethylbenzene and an oxidizing agent such as oxygen or carbon dioxide. The ethylene produced in the oxydehydrogenation unit is separated and used as feed to the alkylation unit.

Abstract: Processes and apparatus are provided that provide high yields of xylenes per unit of aromatic-containing feed while enabling a high purity benzene co-product to be obtained without the need for an extraction or distillation to remove C6 naphthenes. The processes of this invention include a transalkylation section and a disproportionation section in the benzene and toluene-containing feed is directly provided to the transalkylation section and in which a benzene recycle loop in the transalkylation section isolates the disproportionation section from C6 naphthenes.

Abstract: A process for producing a monoalkylation aromatic product, such as ethylbenzene and cumene, utilizing an alkylation reactor zone and a transalkylation zone in series or a combined alkylation and transalkylation reactor zone. This process requires significantly less total aromatics distillation and recycle as compared to the prior art.

Abstract: There are disclosed a process for producing a coupling compound of formula (1): (Y—)(n?1)R1—R2—(R1)(n??1),??(1) wherein R1 and R2 independently represent a substituted or unsubstituted aryl group, which process is characterized by reacting an unsaturated organic compound of formula (2): n?(R1X1n)??(2) wherein n, n?, and R1 are the same as defined above, and X1 is the same or different and independently represents a leaving group and bonded with a sp2 carbon atom of R1 group, with a boron compound of formula (3): m{R2(BX22)n?}??(3) wherein R2 and n? are the same as defined above, X2 represents a hydroxy group, an alkoxy group, in the presence of a catalyst containing (A) a nickel compound, and (B) a nitrogen-containing cyclic compound, and the catalyst.

Abstract: A side-chain of a substituted aromatic compound is alkylated by reacting the aromatic compound with an alkylating agent in the presence of a catalyst. The catalyst comprises a restructured smectite clay to which basic ions are incorporated by ion-exchange. The restructuring of the smectite clay is carried out by acid-treating the clay prior to ion-exchange.

Abstract: The present invention relates to a plasticizer composition, and more particularly a plasticizer composition comprising neopentylglycol ester capable of being using as plasticizer of polyvinyl chloride resin, and method of prepation thereof. The plasticizer composition of the present invention can prepare polyvinyl chloride resin having superior tensile strength, elongation, static heat resistance, and viscosity stability etc.

Abstract: There are disclosed a process for producing a coupling compound of formula (1):

Abstract: A method of preparing an alkenyl-substituted aromatic hydrocarbon, which comprises alkenylating an aromatic hydrocarbon with an olefin using &bgr;-diketone together with a rhodium complex catalyst in the presence of oxygen.

Abstract: The present invention relates to a process for preparing bisindenylalkanes of formula I: wherein R1, R2, R3, and R4 independently represent H or a C1-C6 hydrocarbon group or R1 and R2 or R1 and R3 or R3 and R4 together with the carbon atoms to which they are attached form a saturated or unsaturated 5- or 6-membered ring, said ring being optionally substituted with a C1-C4 hydrocarbon group, and R5 represents a C1-C6 hydrocarbon group, comprising reacting, at a temperature which does not exceed about 5° C., a metallated indene of formula II with a disubstituted hydrocarbon of formula III: wherein R1, R2, R3, R4, and R5 have the same meaning as defined above, M represents a metal ion, and X independently represents a suitable leaving group, in a suitable reaction medium wherein the molar ratio of II to III is 2.05 or higher. The process is particularly suitable for preparing bisindenylethane, i.e., R1-R4 represent H and R5 represents an ethylene group.

Abstract: There are provided a process for producing an alkenyl-substituted aromatic hydrocarbon by alkenylation of an alkyl-substituted aromatic hydrocarbon having a hydrogen atom at the &agr;-position of a side chain thereof with a conjugated diene, using a catalyst obtained by the action of an alkali metal compound and an alkali metal or an alkali metal hydroxide on an metal oxide selected from alumina or hydrotalcite by heating in a specific temperature range; and a process for producing an alkenyl-substituted aromatic hydrocarbon, characterized in that the reaction is carried out in the presence of an alkylaminopyridine of formula (1): wherein R1 is hydrogen or C1-C6 lower alkyl, and R1 is C1-C6 lower alkyl, using as a catalyst, Na metal, K metal, or an alloy thereof, or a catalyst carrying any of them on an inorganic compound support, or a catalyst obtained by the action of an alkali metal compound and alkali metal or an alkali metal hydride on a metal oxide selected from alumina, alkaline earth

Abstract: A method of preparing an alkenyl-substituted aromatic hydrocarbon, which comprises alkenylating an aromatic hydrocarbon with an olefin using &bgr;-diketone together with a rhodium complex catalyst in the presence of oxygen.

Abstract: The invention provides a chain diene compound with desirable regioselectivity, in the presence of a specific ruthenium compound. This chain diene compound is a promising raw material for terpene. It has a structure represented by the general formula (IX): wherein R1 represents H, a C1-C6 alkyl group which may be substituted or a C2-C6 alkenyl group which may be substituted, R2 represents a phenyl group which may have a C1-C4 alkyl group or a C1-C12 acyloxy group which may have a phenyl group or a naphthyl group, or a benzyl group or R2 is a hydroxy group which reversibly forms an aldehyde group through shifting of the position of the double bond adjacent to said hydroxy group. The chain diene compound is produced by reacting 2-substituted-1,3-butadienes with terminal olefins in the presence of a ruthenium compound in a hydrophilic solvent.

Abstract: The invention relates to a process for preparing monofunctional, bifunctional and polyfunctional aromatic olefins of the formula (I) by reacting haloaromatics of the formula (II) with olefins of the formula (III) wherein a palladium compound of the formula (IV) is used as catalyst.

Abstract: This invention relates generally to the field of chemical synthesis, and more specifically, to the field of oxidative coupling of olefinic compounds and aromatic compounds, to produce olefinically substituted aromatic compounds. More particularly, this invention relates to methods for oxidative coupling of olefinic compounds and aromatic compounds which employ a rhodium(III) acetylacetonate catalyst and a copper(II) redox agent in a reaction medium which does not comprise a carboxylic acid component. In one embodiment, this invention pertains to methods for the preparation of styrene by the oxidative coupling of ethylene (an olefinic compound) and benzene (an aromatic compound), in the presence of Rh(acac).sub.2 Cl(H.sub.2 O), as catalyst, and Cu(II)(CH.sub.3 COO).sub.2, as copper(II) redox agent, in which benzene is both a reactant and the reaction medium.

Abstract: Palladium-catalyzed arylation of an olefin (e.g., ethylene) with an aromatic halide (e.g., 2-bromo-6-methoxynaphthalene, m-bromobenzophenone, or 4-isobutyl-1-bromobenzene) is conducted in specified media. After a special acid or base phase separation procedure, palladium-catalyzed carbonylation of the olefinically-substituted aromatic intermediate is conducted in specified media using CO and water or an alcohol to form arylalkylcarboxylic acid or ester or substituted arylalkylcarboxylic acid or ester (e.g., racemic 2-(6-methoxy-2-naphthyl)propionic acid, 2-(3-benzoylphenyl)propionic acid, or 2-(4-isobutylphenyl)propionic acid). Catalyst recovery procedures enabling recycle of catalyst residues and efficient recovery of amine hydrogen halide scavenger and solvent used in the arylation reaction are described, as well as novel, highly efficient methods of conducting the carbonylation reaction.

Abstract: The invention relates to a process for preparing monofunctional, bifunctional or polyfunctional aromatic olefins of the formula (I) ##STR1## wherein a palladium compound of the formula (IV) ##STR2## is used as a catalyst in the preparation of the compounds of the formula (I).

Abstract: A method for producing a monoalkenyl benzene including reacting an alkyl benzene having 7 to 10 carbon atoms with a conjugated diene compound having 4 to 6 carbon atoms in the presence of a particular catalyst. The particular catalyst is obtained by depositing at least one of sodium, potassium, sodium amide, and potassium amide on a support made of a compound represented by the formula of K.sub.2 O.xAl.sub.2 O.sub.3 wherein x is 0.5.ltoreq.x.ltoreq.11, to obtain a precursor of a catalyst, and contacting the precursor of a catalyst with at least one of water, an alcohol, and a phenol. The precursor of the catalyst may be contacted with hydrogen before contacted with at least one of water, an alcohol, and a phenol.

Abstract: A process for manufacturing an alkenyl compound which comprises reacting an alkylbenzene and 1,3-butadiene in the presence of metallic sodium or a combination of metallic sodium and an oxide, a hydroxide, or a salt of potassium, rubidium or an alkaline earth metal, or a mixture of these under a pressure of 1 kPa (gauge) to 30 MPa (gauge). The process can produce alkenyl compound which is an industrially valuable compound as a raw material for the manufacture of naphthalenedicarboxylic acid, a highly useful raw material of polymers, at a high yield using a small amount of metallic sodium.

Abstract: A process for producing a monoalkenyl aromatic hydrocarbon which comprises alkenylating a side chain of an aromatic hydrocarbon compound having at least one hydrogen atom at the .alpha.-position of a side chain (such as o-xylene) with a conjugated diene having 4 or 5 carbon atoms in the presence of a catalyst slurry prepared by adding an aromatic hydrocarbon compound to a catalyst comprising a alkali metal and an alkali metal compound. In the aforementioned process, it is particularly effective that the catalyst slurry is prepared by adding the aromatic hydrocarbon compound after the aromatic hydrocarbon compound has been deoxygenated and dehydrated by distillation, and the catalyst slurry thus prepared is supplied to the reaction system. According to the aforementioned process, an industrially useful monoalkenyl aromatic hydrocarbon compound, such as a monoalkenylbenzene, can be produced at a high selectivity, in a high yield, and with enhanced safety and stability for a long time.

Abstract: A process for manufacturing an alkenyl aromatic compound which is an industrially valuable compound as a raw material for the manufacture of naphthalenedicarboxylic acid, a highly useful raw material of polymers. The process comprises reacting an alkylbenzene and 1,3-butadiene in the presence of (a) metallic sodium, (b) at least one compound selected from the group consisting of salts of potassium, salts of rubidium, and salts of an alkaline earth metal, and (c) an aromatic compound capable of producing a charge-transfer complex together with metallic sodium. High purity alkenyl aromatic compound can be manufactured at a high yield using a simple procedure.

Abstract: The present invention relates to a process for preparing vinyl-substituted aromatic compounds of the formula (I) Ar--CH.dbd.CH.sub.2, where Ar is a phenyl group that may bear 1 to 5 substituents, naphthyl or anthryl or a naphthyl radical bearing 1 to 7 substituents or an anthryl radical bearing 1 to 8 substituents, or a mononuclear five-, six- or seven-membered heterocyclic aromatic group which contains an oxygen atom and/or one or two nitrogen atoms in the ring and may bear 1 to 5 substituents, wherein an arylamine of the formula (II) Ar--NH.sub.2, where Ar has the aforementioned meaning, is reacted in an organic acid with an organic nitrite of the formula (III) R--ONO, where R is an alkyl group having 1 to 18 carbon atoms, a phenyl radical which may bear 1 to 3 alkyl groups each having 1 to 4 carbon atoms, or is an alkylcarbonyl group having 2 to 5 carbon atoms, and ethylene in an organic solvent in the presence of a palladium(0) of palladium(II) compound at temperatures of 0.degree. to 35.degree. C.

Abstract: There is disclosed a process for producing a monoalkenylbenzene which comprises alkenylating a side chain of an aromatic hydrocarbon compound having at least one hydrogen atom bonded at .alpha.-position of the side chain (such as xylene) with a conjugated diene having 4 or 5 carbon atoms (such as butadiene) in the presence of a catalyst produced by calcining the mixture of a basic potassium compound and alumina and then heat treating the calcined product together with metallic sodium in an atmosphere of an inert gas. According to the aforesaid process, an industrially useful monoalkenylbenzene can be produced in high yield at a low cost with enhanced safety.

Abstract: There is disclosed a process for producing a monoalkenylbenzene which comprises alkenylating a side chain of an aromatic hydrocarbon compound having at least one hydrogen atom bonded at .alpha.-position of the side chain (such as xylene) with a conjugated diene having 4 or 5 carbon atoms (such as butadiene) in the presence of a catalyst produced by calcining the mixture of potassium hydroxide and aluminum hydroxide and then heat treating the calcined product together with metallic sodium in an atmosphere of an inert gas. According to the aforesaid process, an industrially useful monoalkenylbenzene can be produced in high yield at a low cost with enhanced safety.

Abstract: There is disclosed a process for producing a monoalkenyl aromatic hydrocarbon compound which comprises alkenylating a side chain of an aromatic hydrocarbon compound having at least one hydrogen atom bonded at .alpha.-position of the side chain (such as xylene) with a conjugated diene having 4 or 5 carbon atoms (such as butadiene) in the presence of a catalyst comprising the mixture obtained by heat treating metallic sodium together with an alkaline earth metal oxide containing a potassium compound in the atmosphere of an inert gas. According to the aforesaid process, a monoalkenyl aromatic hydrocarbon compound such as industrially useful monoalkenylbenzene can be produced in high yield at a low cost with enhanced safety from a specific aromatic hydrocarbon compound and a specific conjugated diene compound.