Abstract: A process for the hydrogenolysis and/or dehydrohalogenation of fluorohalocarbons and/or fluorohalohydrocarbons by reacting the fluorohalocarbons and/or fluorohalohydrocarbons with a source of hydrogen in the presence of a catalyst, the improvement comprising utilizing a rhenium-containing catalyst, which may, optionally, contain at least one Group VIII metal and may, optionally, be supported.
Type:
Grant
Filed:
June 26, 1991
Date of Patent:
September 8, 1992
Assignee:
E. I. du Pont de Nemours and Company
Inventors:
Carl S. Kellner, V. N. Mallikarjuna Rao, Frank J. Weigert
Abstract: 2,6-Difluoroaniline is prepared from 1,2,3-trichlorobenzene by partial fluorine exchange to a mixture of 2,6-difluorochlorobenzene and 2,3-difluorochlorobenzene, amination of the chloro substituents, and separation of the desired product from the isomeric 2,3-difluoroaniline. By incorporating a selective reduction into the process immediately after the partial fluorine exchange, the undesirable 2,3-difluorochlorobenzene is converted into valuable ortho-difluorobenzene and the 2,3-difluoroaniline isomer is avoided.
Abstract: A process for the hydrogenolysis and/or dehydrohalogenation of fluorohalocarbons and/or fluorohalohydrocarbons by reacting the fluorohalocarbons and/or fluorohalohydrocarbons with a source of hydrogen in the presence of a catalyst, the improvement comprising utilizing a rhenium-containing catalyst, which may, optionally, contain at least one Group VIII metal and may, optionally, be supported.
Type:
Grant
Filed:
October 17, 1990
Date of Patent:
November 26, 1991
Assignee:
E. I. du Pont de Nemours and Company
Inventors:
Carl S. Kellner, V. N. Mallikarjuna Rao, Frank J. Weigert
Abstract: A process for producing 2-halofluorobenzene from 2,4-dihalofluorobenzenes comprises treating an aqueous slurry of 2,4-dihalofluorobenzene with hydrogen at an elevated temperature in the presence of a transition metal supported on a carbon catalyst. The process produces a mixture including fluorobenzene and 2-halofluorobenzene. The 2-halofluorobenzene can be separated from the mixture by conventional means such as distillation. Optionally, the fluorobenzene also can be recovered.
Abstract: Catalytic transhalogenation of haloaromatics according to the equation:C.sub.z F.sub.a X.sub.b N.sub.e L.sub.1 +C.sub.z F.sub.c X.sub.d N.sub.e L.sub.2 .fwdarw.C.sub.z F.sub.a+1 X.sub.b-1 N.sub.e L.sub.1 +C.sub.z F.sub.c-1 X.sub.d+1 N.sub.e L.sub.2wherein:when C.sub.z is a benzene derivative, a+b=5; e=0; c+d=5; z=6;when C.sub.z is a pyridine derivative, a+b=4; e=1; c+d=4; z=5;when C.sub.z is a naphthalene derivative, a+b=7; e=0; c+d=7; z=10; andwhen C.sub.z is a biphenyl derivative, a+b=9; e=0; c+d=9; z=12;L.sub.1 and L.sub.2, alike or different, are selected from F, Cl, Br, H, CN, C.sub.n F.sub.2n+1, and C.sub.6 F.sub.5 ;X is Cl, Br, or I when C.sub.z is a benzene derivative; andn is 1 to 12. This method is a novel route to known haloaromatic compounds.
Abstract: Novel alumina-supported nickel boride catalysts prepared by the borohydride promoted reduction of nickel arsenate are described. Method of catalyst preparation and process for hydrogenation of acetylenic and diolefinic compounds employing the invention catalysts are also described.
Abstract: This invention relates to the fluorination of carboxylic acids with xenon difuoride in the presence of hydrogen fluoride. Novel fluorinated compounds containing aliphatic unsaturation are also disclosed.
Abstract: Halogenated, unsaturated alcohols are dehydrated by contacting the alcohol and a carrier gas with a silica alumina catalyst to form dienes of the formula: ##STR1## wherein each X is independently hydrogen, fluorine chlorine, or bromine with the proviso that no more than one of them is hydrogen, and each R is independently hydrogen, alkyl, aralkyl, alkaryl, or aryl.
Abstract: The alkylation of para-substituted isopropyl benzenes with dipentenes employing an aluminum halide catalyst system produces novel tetracyclic compounds.
Abstract: The invention is a process for the preparation of an aromatic hydrocarbon with a cyclobutene ring fused to the aromatic hydrocarbon which comprises, dissolving an ortho alkyl halomethyl aromatic hydrocarbon in an inert solvent and pyrolyzing the solution of ortho alkyl halomethyl aromatic hydrocarbon in the inert solvent under conditions such that the ortho alkyl and halomethyl substituents form a cyclobutene ring thereby forming an aromatic hydrocarbon having a fused cyclobutene ring.
Abstract: Bromohalogenobenzenes are isomerized to useful, e.g., pharmaceutical or phytosanitary intermediates, by contacting the same with an alkaline base and a catalyst compound which forms a complex with the cation of said alkaline base.
Abstract: Substituted bromofluorobenzene, wherein the fluorine is in para-position and the bromine in meta-position to another substituent, is prepared by direct bromination of the corresponding fluorobenzene derivative. Bromination is advantageously carried out in the presence of a catalyst, preferably a metal or metal salt. The elementary bromine is used in an amount of 0.9 to 1.3 mols per mol of fluorobenzene derivative and the reaction temperature is between 20.degree. and 200.degree. C. The bromofluorobenzene derivatives are suitable for the synthesis of medicaments and plant protective agents.
Abstract: There is provided a process for effecting fluorination of benzene, p-difluorobenzene or p-dichlorobenzene by subjecting the same to the action of argentic fluoride (AgF.sub.2) in the liquid phase to obtain fluorobenzene from benzene or a fluorinated cyclohexadiene from halogenated benzene, respectively, in good yield and purity.
Abstract: Fluorobenzenesulfonyl fluorides are prepared by chlorine/fluorine exchange fluorinating a chlorobenzenesulfonyl fluoride with an alkali metal fluoride, in a aprotic polar solvent and at a temperature ranging from about 100.degree. C. to about 240.degree. C.
Abstract: Organosilicon compounds referred to as silacrown ethers or "silacrowns" are of the general formula: ##STR1## where R.sup.1 and R.sup.2 are organic radicals or hydrogen and n is an integer between 4 and 10 inclusive. Silacrown ethers are prepared by reacting polyethylene glycol with substituted silanes under conditions promoting cyclization over polymerization. Silacrown ethers may be employed as phase-transfer catalysts in solution or immobilized on siliceous supports.
Abstract: Compounds of the formula I ##STR1## in which Z, Z.sub.1, R, m and p are as defined in patent claim 1, can be obtained in a simple and economical manner by a novel process wherein a halide of the formula II ##STR2## is reacted with a substituted or unsubstituted vinylbenzene or vinylnaphthalene derivative in the presence of a base and of certain palladium catalysts, such as palladium acetate. The compounds (I) or functional derivatives preparable therefrom are useful, for example, for the preparation of known dyes or fluorescent brighteners, or can be used directly as fluorescent brighteners or as scintillators.
Abstract: Benzotrihalides are prepared by pyrolyzing a substituted phenyl trihaloacetate of the formula ##STR1## wherein each X is halo, nitro, alkyloxy, aryloxy, aralkyoxy, cyano, lower alkyl, haloalkyl, haloalkyloxy, alkenyl, haloalkenyl, carbamoyl, N,N-dialkylcarbamoyl, N,N-diarylcarbamoyl, or N,N-diaralkyloxy;Y is halo; andn is an integer of from 1 to 5. As an example, 4-chlorophenyl trichloroacetate is pyrolyzed at 550.degree. C. to 4-chlorobenzotrichloride.
Abstract: The present invention relates to a process for the preparation of aromatic or furyl substituted olefins, which comprises reacting an olefinic compound with an aromatic compound or furan compound in the presence of carbon monoxide by using a rhodium carbonyl complex as a catalyst to form a corresponding aromatic or furyl substituted olefin.