Abstract: 2,2-diphenylhexafluoropropanes are prepared by condensation reaction of benzene or benzenes substituted with a halogen atom or atoms, a lower alkyl group or groups or a hydroxyl group or groups with hexafluoroacetone in the presence of trifluoromethane sulfonic acid. Among the 2,2-diphenylhexafluoropropanes, 2,2-diphenylhexafluoropropane and 2,2-bis(p-chlorophenyl)hexafluoropropane are novel compounds.

Abstract: Partially fluorinated benzene derivatives of the formula I ##STR1## in which R, A.sup.1, A.sup.2, Q, Y, L.sup.1, L.sup.2, L.sup.3 and m are as defined in claim 1,are suitable as components of liquid-crystalline media.

Abstract: Methyl aromatic compounds of the formula (I) ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 have the meaning given in the description,can be reacted in an advantageous manner using free-radicals to give the associated trichloromethyl or tribromomethyl aromatic compounds, if the reaction is carried out in the presence of one or more chlorides or bromides of the heavy alkali metals.

Abstract: Fluorine-containing, chiral liquid crystal compounds comprise (a) a chiral fluorochemical terminal portion containing at least one methylene group and optionally containing at least one catenary ether oxygen atom; (b) a saturated, chiral or achiral, hydrocarbon terminal portion; and (c) a central core connecting the terminal portions. The compounds have smectic mesophases or latent smectic mesophases and are useful, for example, in liquid crystal display devices.

Abstract: A novel liquid crystalline compound having a high elastic constant ratio, K.sub.33 /K.sub.11, a superior compatibility with other liquid crystal compounds, particularly a low temperature compatibility therewith, and chemical stability; a liquid crystal composition containing such a liquid crystalline compound; and a liquid crystal display element, are provided,which liquid crystalline compound is expressed by the formula (1) ##STR1## wherein R.sub.1 is an alkyl group or an alkyloxy group of 1 to 10C or a halogenated alkyl group, a halogenated alkyloxy group of 1 to 4C, halogen atom or cyano group; R.sub.2 is H atom or an alkyl group of 1 to 3C; rings A and B each independently are 1,4-phenylene ring or trans-1,4-cyclohexylene group, which may be substituted by halogen atom; Z is single bond, 1,4-phenylene ring, trans-1,4-cyclohexylene ring or 1,2-ethylene group; p is 2 to 4; and q is 0 or 1.

Abstract: 1,2,2,2-Tetrafluoroethyl ethers of the formula IR--(A.sup.1 --Z.sup.1).sub.m --A.sup.2 --Z.sup.2 A.sup.3 --O--CHF--CF.sub.3(I)are suitable as components of liquid-crystalline media whereinR is H, a substituted or unsubstituted alkyl or alkenyl radical having 1 to 15 carbon atoms,A.sup.1 and A.sup.2 are each, independently of one another, a(a) trans-1,4-cyclohexylene radicals and derivatives thereof in which, in addition, one or more non-adjacent CH.sub.2 groups is optionally replaced by --O-- and/or --S--,(b) 1,4-phenylene radicals and derivatives thereof in which, in addition, one or two CH groups is optionally replaced by N, or(c) radical from the group consisting of 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl and 1,2,3,4-tetrahydronaphthalene-2,6-diyl,wherein radicals (a) and (b) are optionally substituted by one or two fluorine atoms,Z.sup.1 and Z.sup.2 are each, independently of one another, --CO--O--, --O--CO--, --CH.sub.

Abstract: A nematic liquid crystalline medium having at least two liquid crystalline components with at least one being of formula I ##STR1## wherein R is H, a straight-chain alkyl or alkenyl radical having 1 to 15 carbon atoms, it also being possible to replace one or more CH.sub.2 groups in these radicals, independently of one another, by --O--, --S--, ##STR2## --CO--, --CO--O--, --O--CO-- or --O--CO--O-- in such a way that oxygen atoms are not linked directly to one another,Z.sub.1 and Z are each, independently of one another, --CH.sub.2 --CH.sub.2 --, --CH.dbd.CH--, --C.tbd.C-- or a single bond, and one of the radicals Z.sup.1 and Z is alternatively --(CH.sub.2).sub.4 -- or --CH.dbd.CH--CH.sub.2 CH.sub.2 --,A and A.sup.1 are each, independently of one another, trans-1,4-cyclohexylene in which, in addition, one or two non-adjacent CH.sub.

Abstract: A 1,1,2-trifluoro-2-(trans-4-substituted cyclohexyl)ethylene of the formula (1):R--(A).sub.m --Cy--CF=CF.sub.2 (1)wherein R is a C.sub.1-10 alkyl group, a halogen atom or a cyano group, provided that in the case of the alkyl group, an oxygen atom may be interposed in a carbon-carbon bond of the alkyl group or in a carbon-carbon bond between this alkyl group and A, some of carbon-carbon bonds in the alkyl group may be triple bonds or double bonds, one --CH.sub.2 -- group in the alkyl group may be substituted by a carbonyl group, and some or all of hydrogen atoms in the alkyl group may be substituted by fluorine atoms;Cy is an unsubstituted trans-1,4-cyclohexylene group;A is a trans-1,4-cyclohexylene group, a 1,4-phenylene group or a 1,4-cyclohexenylene group, wherein each of such cyclic groups is unsubstituted or substituted by one or more halogen atoms or cyano groups, one or more =CH-- groups constituting rings of such cyclic groups may be substituted by nitrogen atoms, and one or more --CH.sub.

Abstract: 2-Trifluoromethyl-4-chloro-benzalchloride and 2-methyl-3-nitro-5-chlorobenzotrifluoride, are intermediates in a process of preparing 2-methyl-3-aminobenzo-trifluoride. In this process, 2-trifluoromethyl-4-chlorobenzal-chloride is prepared by chlorinating o-trifluoromethylbenzalhalide, and 2-methyl-3-nitro-5-chlorobenzotrifluoride is prepared at first by hydrogenating the 2-trifluoro-methyl-4-chlorobenzalhalide to form a 2-methyl-5-monochlorobenzotrifluoride and then by nitrating the 2-methyl-5-monochlorobenzotrifluoride. Following this process, 2-methyl-3-aminobenzotrifluoride (MA-BTF) is prepared by hydrogenating the 2-methyl-3-nitro-5-chlorobenzotrifluoride. The thus prepared 2-methyl-3-aminobenzotrifluoride is useful as an intermediate in preparing medicines, agricultural chemicals and other chemical products.

Abstract: Benzene derivatives of the formula I ##STR1## in which R, A.sup.1, A.sup.2 X, L.sup.1, L.sup.2 m and n are as defined in claim are suitable as components of liquid-crystalline media.

Abstract: The invention relates to liquid crystalline, multiply-substituted fluorinated tolane derivatives, their preparation, liquid crystalline mixtures which comprise such compounds and the use of these compounds and mixtures for electro-optical purposes.

Abstract: Partially fluorinated benzene derivatives of the formula I ##STR1## in which R, A.sup.1, A.sup.2, Z.sup.1, Z.sup.2, L.sup.1, L.sup.2 and m are as defined in claim 1, are suitable as components of liquid-crystalline media.

Abstract: A process for the preparation of octafluoro-[2,2]paracyclophane includes contacting a reactant selected from the group consisting of 1,4-bis (bromodifluoromethyl)benzene (dibromide), 1,4-bis (chlorodifluoromethyl)benzene (dichloride), and 1,4-bis (iododifluoromethyl)benzene (diiodide) with trimethylsilyltributyltin (TMSTBT) (a reducing agent) and fluoride ions in a refluxing solution of hexamethylphosphoramide (HMPA) or dimethylsulfoxide (DMSO) in tetrahydrofuran (THF) at conditions effective to promote a reaction product comprising octafluoro-[2,2]paracyclophane.

Abstract: Trifluorophenylene compounds of the formula (I) ##STR1## in which ##STR2## are mesogenic radicals, are useful components for liquid-crystal mixtures.

Abstract: Compounds such as ##STR1## wherein R is F, CF.sub.3, CF.sub.2 H, CHF CF.sub.3 or CF.sub.2 CF.sub.3, as well as related compounds containing chlorine, are used as solvents in halogenation processes.

Abstract: Aryl halide, such as idodobenzene, is reacted with perfluoromethoxycarboxylate, such as CF.sub.3 OCF.sub.2 CO.sub.2 K, in the presence of CuI and an inert aprotic polar solvent to obtain trifluoromethylaryl.

Abstract: 3-Fluoro-4,6-dichlorotoluene is prepared with reduced formation of 3-fluoro-2,6-dichlorotoluene by chlorinating 3-fluorotoluene in the presence of a catalyst system to give a mixture containing 3-fluoro-6-chlorotoluene and 3-fluoro-4-chlorotoluene and chlorinating this in the presence of another catalyst system to give 3-fluoro-4,6-dichlorotoluene.

Abstract: Fluoromethyl ketones of the formula I ##STR1## are suitable as components of liquid-crystalline media wherein R is H, a substituted or unsubstituted alkyl or alkenyl radical having 1 to 15 carbon atoms,A.sup.1 and A.sup.2 are each, independently of one another, a(a) trans-1,4-cyclohexylene radicals and derivatives thereof in which, in addition, one or more non-adjacent CH.sub.2 groups is optionally replaced by --O-- and/or --S--,(b) 1,4-phenylene radicals and derivatives thereof in which, in addition, one or two CH groups is optionally replaced by N, or(c) radical from the group consisting of 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl and 1,2,3,4-tetrahydronaphthalene-2,6-diyl,wherein radicals (a) and (b) are optionally substituted by one or two fluorine atoms,Z.sup.1 and Z.sup.2 are each, independently of one another, --CO--O--, --O--CO--, --CH.sub.2 O--, --OCH.sub.2 --, --CH.sub.2 CH.sub.2 --, --CH.dbd.CH--, --C.tbd.

Abstract: Cyclofluoralkylated fullerene compounds are prepared by reacting the fullerenes with a fluoroalkene as exemplified by tetrafluoroethylene or perfluoromethyl vinyl ether under thermolysis conditions as exemplified by temperatures of 200.degree. C., pressure and a halocarbon solvent, the products being useful as lubricants or additive thereto as well as in cooling systems, adhesives and polymers.

Abstract: This invention provides a mixture of fluoroalkylated fullerene compounds, preferably perfluoroalkylated fullerene compounds, comprising the formula, (C.sub.60+2n) R.sup.1.sub.m R.sup.2.sub.b Z.sub.y, wherein R.sup.1 is a branched or straight chain hydrocarbon or aromatic hydrocarbon of from 1 to about 100 carbon atoms; R.sup.2 is a branched or straight chain fluoroalkyl group of from 1 to about 100 carbon atoms; Z is one or more selected from H, F and Cl; n is an integer from 0 to about 470; m is an integer from 0 to about 24+n; b is an integer from 1 to about 24+n; and y is an integer from 0 to about 35+n.

Abstract: Mixtures of cyclofluoroalkylated fullerenes are provided by the thermal 2+2 cycloaddition of fluoroalkenes to a solution or slurry of a fullerene. The cyclofluoroalkylated fullerene mixtures are useful as lubricants or additives to lubricants; in fluorocarbon and/or chlorofluorocarbon based cooling systems; in adhesives for fluorocarbon based polymers and in gas separation membranes.

Abstract: This invention provides a mixture of fluoroalkylated fullerene compounds, preferably perfluoroalkylated fullerene compounds, comprising the formula, (C.sub.60+2n)R.sup.1.sub.m R.sup.2.sub.b Z.sub.y, wherein R.sup.1 is a branched or straight chain hydrocarbon or aromatic hydrocarbon of from 1 to about 100 carbon atoms; R.sup.2 is a branched or straight chain fluoroalkyl group of from 1 to about 100 carbon atoms; Z is one or more selected from H, F and Cl; n is an integer from 0 to about 470; m is an integer from 0 to about 24+n; b is an integer from 1 to about 24+n; and y is an integer from 0 to about 35+n.

Abstract: Substrate compounds are reacted by passing them through an eductor with fluorine gas optionally in the presence of a liquid medium and preferably in a loop reactor with cooling means thereby providing rapid but controlled reaction suitable for industrial scale production. Vinylidene chloride, for example, smoothly produces dichlorodifluoroethane and dichlorotrifluoroethane in good yield.

Abstract: A process for halogen exchange fluorination or fluoro-denitration of aromatic compounds having at least one replaceable non-fluorine halogen or nitro substituent with an anhydrous substantially molten alkali metal acid fluoride composition wherein the alkali metal is potassium, rubidium or cesium.

Abstract: The disclosure relates to fluorinated chiral liquid crystals that incorporate a cyclohexyl grouping in their structure. They can be used as dopants and lead to mixtures of ferroelectric liquid crystals that have an application in display systems. They meet the following chemical formula. ##STR1## with 1.ltoreq.n.ltoreq.14 if X=CH.sub.2 Y=--CH.sub.2 -- with R=CmH.sub.2m+1 and 5.ltoreq.m.ltoreq.

Abstract: Fluorine- and chlorine- and/or bromine-containing aromatic compounds are dechlorinated and/or debrominated with hydrogen in an industrially advantageous and selective manner, if the palladium catalyst is present in stationary phase and the aromatic compound in gas phase.

Abstract: A process is provided for the catalytic perfluoroalkylation of aromatic compounds, wherein a perfluoroalkyl iodide or mixture of iodides is reacted with an aromatic compound in the presence of an aqueous base, such as an alkali metal hydroxide or carbonate. The use of an aqueous strong base increases the rate of reaction. Further improvements in rate and yield are secured by employing, as the catalyst, a noble metal supported on porous silica microspheres.

Abstract: The preparation of Z-1,2-diarylallyl chlorides of the general formula I ##STR1## in which R.sup.1 and R.sup.2, independently of one another, are hydrogen, halogen, alkyl, haloalkyl, alkoxy, haloalkoxy or a substituted aromatic radical, and n and m are 1, 2 or 3, by dehydrating chlorohydrins of the formula II ##STR2## in which the radicals are as defined above, at up to 50.degree. C. in an inert ether or carboxylic acid ester as solvent and in the presence of a carboxylic anhydride and an organic or inorganic acid, the conversion thereof into azolylmethyloxiranes, and novel intermediates are described.

Abstract: Compounds are provided which comprise a fluorocarbon terminal portion and a chiral hydrocarbon terminal portion, said terminal portions being connected by a central core, said compounds having tilted smectic mesophases or having latent tilted smectic mesophases which develop when said compounds having said latent mesophases are in admixture with said compounds having tilted smectic mesophases or said compounds having latent tilted smectic mesophases.

Abstract: The invention describes a process for selectively preparing ortho-fluorinated substituted aromatic compounds wherein an aromatic compound containing a substituent capable of directing ortho metalation is contacted with a metalating reagent under reaction conditions sufficient to form an ortho-metalated substituted aromatic compound. The ortho-metalated substituted aromatic compound is reacted with an electrophilic fluorinating reagent under reaction conditions sufficient to form the desired ortho-fluorinated substituted aromatic compound which is then recovered from the reaction mixture. The process which utilizes a metalation intermediate prior to effecting the electrophilic fluorination step overcomes problems associated with prior art electrophilic fluorination processes which do not proceed through a regiospecifically controlled intermediate.

Abstract: Aromatic compound are trifluoromethylated by reaction in the vapor phase with a dihalodifluoromethane in the presence of a copper/copper fluoride catalyst.

Abstract: The invention relates to novel benzene derivatives of the formula I ##STR1## in which n is 0, 1, 2, 3, 4, 5, 6 or 7,Q is --O--, --CH.dbd.CH-- or a single bond,r is 0, 1, 2, 3, 4 or 5,s is 0, 1 or 2,X is F, Cl, OCHF.sub.2 or CF.sub.3,L is H or F, andA is ##STR2## Z, Z-Ar, Ar-Z, Z-Cyc in which Z is a single bond, --(CH.sub.2).sub.2 -- or --(CH.sub.2).sub.4 --, Ar is 1,4-phenylene or biphenyl-4,4'-diyl and Cyc is trans-1,4-cyclohexylene.

Abstract: Introduction of a fluoro substituent into an aromatic ring adjacent an electron donating group is difficult producing mixed isomers and low yields of desired products.A process for the introduction of a fluoro substituent into a substantially adjacent position to an electron-donating group into an aromatic compound in high yield is disclosed.The fluoroaromatic compounds are useful as synthetic intermediates for example in the manufacture of agrochemicals, pharmaceuticals and dyestuffs.

Abstract: Processes are disclosed for the preparation of octafluoro-[2,2]paracyclophane which utilize a low temperature, e.g., less than about 200.degree. C., and a reducing agent comprising titanium to promote the dimerization of dihalo-tetrafluoro-p-xylenes. One suitable reducing agent is prepared by combining TiCl.sub.4 with LiAlH.sub.4 in an organic solvent.

Abstract: Substrate compounds are reacted by passing them through an eductor with fluorine gas optionally in the presence of a liquid medium and preferably in a loop reactor with cooling means thereby providing rapid but controlled reaction suitable for industrial scale production. Vinylidene chloride, for example, smoothly produces dichlorodifluoroethane and dichlorotrifluoroethane in good yield.

Abstract: A novel fluorine-containing aromatic compound of the formula: ##STR1## wherein X is ##STR2## in which R.sub.f is a perfluoroalkyl group having 1 to 10 carbon atoms,R.sub.f ' is a perfluoroalkyl group having 1 to 12 carbon atoms,p is an integer of 1 to 3,q is an integer of 0 to 3,r is 0 or 1,s is an integer of 0 to 5and t is an integer of 0 to 5,Y is X, a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a fluoroalkyl group having 1 to 8 carbon atoms, andeach A is independently ##STR3## in which D is an amino, carboxyl, hydroxyl, methyl or haloformyl group, and n is an integer of 1 or 2, or ##STR4## can be used to derive various compounds, some of which are useful for preparing a fluorine-containing epoxy compound of polyimide with good properties.

Abstract: A novel process for the lithiation of 1,3-bis(trifluoro-methyl)benzene in a solvent is described, said process comprising carrying out the lithiation with the lithium salt of an amine of the general formulaR.sup.1 R.sup.2 NH Iwherein R.sup.1 and R.sup.2 are secondary or tertiary lower alkyl or secondary or tertiary lower alkyl substituted by a lower alkyl or lower cycloalkyl or lower cycloaklyl substituted by a lower alkyl, or R.sup.1 and R.sup.2 taken together form a C.sub.6-14 -alkylene group in which the two carbon atoms linked with the nitrogen atom are secondary or tertiary and are separated from each other by 2 to 4 carbon atoms.The solution of the lithiated 1,3-bis(trifluoromethyl)-benzene obtained can be reacted with an electrophile which is suitable for the substitution of lethiated benzene derivatives, whereby a compound of the formula ##STR1## wherein R.sup.3 signifies the residue of an electrophile which is suitable for the substitution of lithiated benzene derivatives, is obtained.

Abstract: A partially deactivated reduction catalyst is prepared by reacting palladium on alumina catalyst with benzotrifluoride in an amount of 0.1 to 10.0 millimoles of benzotrifluoride per gram of alumina and hydrogen in an amount ranging from 10 to 2000 moles of hydrogen per mole of benzotrifluoride at a temperature of 200.degree. C. to 300.degree. C. for 30 minutes to 2 hours. The catalyst is useful for the reduction of trifluoromethylbenzonitriles and trifluoromethylbenzylamines to produce the corresponding trifluoromethyltoluenes in high yields. The catalyst is also useful in other hydrogen reduction reactions, e.g., for conversion of o-chlorobenzonitrile, o-chlorobenzylamine and mandelonitrile to toluene and for conversion of phenethylamine to ethylbenzene.

Abstract: Fluoroalkyl derivatives which are novel compounds represented by the following general formula (I) or (II) of: ##STR1## orR.sub.1 --CH.dbd.CR.sub.2 (CF.sub.2).sub.n F (II)(wherein R.sub.1 stands for ##STR2## (where X stands for a hydrogen atom, a chlorine atom, a bromine atom, a fluorine atom, an iodine atom, a methyl group, an ethyl group, a methoxy group, an ethoxy group or a nitro group), an aroyloxy group, or an alkyl or alkoxycarbonyl group having 1 to 20 carbon atoms, and R.sub.2 stands for a hydrogen atom or a methyl group; and n stands for an integer of from 1 to 20.) A process for the preparation of the derivative is a process comprising reacting an olefin compound and a fluoroalkanesulfonyl chloride in the presence of a metal catalyst, or a process comprising an additional alkali treatment step which follows the aforementioned process.

Abstract: Difluoromethylene compounds of the formula IR.sup.1 --(A.sup.1 --Z.sup.1).sub.m --A.sup.2 --Q--CF.sub.2 --(A.sup.3 --Z.sup.2).sub.n --A.sup.4 --R.sup.2 Iin which R.sup.1, R.sup.2, A.sup.1, A.sup.2, A.sup.3, A.sup.4, Z.sup.1, Z.sup.2, m and n are as defined herein and Q is --CO--, --O-- or --S--, can be used as components of liquid-crystalline media for liquid-crystal and electrooptical display elements.

Abstract: Disclosed is a method of making a bisphenyl dihalomethane by reacting a trihalomethylbenzene with a halobenzene and a Lewis acid. The bisphenyl dihalomethane can than be reacted with water to form a halobenzophenone. In an optical third step ring chlorines that are present can be replaced with fluorines and, in a final step, any remaining chlorines can be removed to leave a fluorobenzophenone. The process is particularly useful in making 4,4'-difluorobenzophenone, which is in turn useful in making polyetheretherketones.

Abstract: Halogen substituted aromatic compounds of the formula ##STR1## wherein Y is selected from the group CO.sub.2 H, COF, COCl, COBr, CF.sub.3, CN, NCO, or F, and X and X' are independently hydrogen or a halogen selected from the group F-, Cl- and Br-, at least one of X and X' being halogen; may be prepared by the liquid phase reaction of a brominating agent, at temperatures below about 190.degree. Celsius, with a correspondingly substituted cyclohexene or cyclohexadiene.

Abstract: Benzotrifluorides substituted by fluorine and optionally in addition by chlorine, some of which are new, are prepared by hydrogenating benzotrifluorides which are substituted by fluorine and chlorine, in the presence of a catalyst and a hydrogen chloride acceptor.

Abstract: 3,4-Difluorobenzotrifluoride is prepared by contacting a 3,4-dihalobenzotrifluoride with an effective amount of KF or CsF in a polar aprotic solvent at an elevated temperature under substantially anhydrous conditions. The product can be removed as it is formed or the reaction may be run at the autogenous pressures generated by the reaction mixture in a sealed reactor.

Abstract: A process for preparing (polyfluoroalkyl)polyfluoroarenes comprising contacting a polyfluoroalkyl or perfluoroalkylene of specified formulae with a polyfluoroaromatic in the presence of at least one specified metal reagent is disclosed.

Abstract: The process of direct synthesis of trifluoromethyl copper and trifluoromethyl aromatics, both intermediate reagents useful in direct synthesis of certain perfluoroalkyl compounds. The process involves a direct reaction between on the one hand an aromatic halide and a difluorodihalomethane and on the other hand copper and a difluorodihalomethane.

Abstract: Benzotrifluorides substituted by fluorine and optionally in addition by chlorine, some of which are new, are prepared by hydrogenating benzotrifluorides which are substituted by fluorine and chlorine, in the presence of a catalyst and a hydrogen chloride acceptor.

Abstract: Novel 3-phenylpyrrole derivatives of the formula I ##STR1## wherein R.sup.1 is cyano, trifluoromethyl or C.sub.1 -C.sub.4 -alkoxycarbonyl, R.sup.2 is vinyl or a group --CH.sub.2 --CH.sub.2 --X, in which X is chlorine or bromine, or is cyano, C.sub.1 -C.sub.4 -alkoxycarbonyl, phenylsulfonyl, 4-bromophenylsulfonyl or 4-methylphenylsulfonyl, R is halogen, C.sub.1 -C.sub.4 -alkyl or C.sub.1 -C.sub.4 -haloalkyl, and n is zero, one or two, have valuable microbicidal properties for controlling phytopathogenic plant pests, particularly phytopathogenic fungi.

Abstract: A process for preparing ring-halogenated .alpha.-methylstyrenes from the corresponding .alpha.-halocumenes is disclosed. The dehydrohalogenation is accomplished using only water and optionally an organic solvent. The process eliminates the need for added base and a phase-transfer catalyst.

Abstract: Aromatic bromine compounds are prepared by reacting aromatic nitro compounds with elemental bromine in the gas phase at temperatures between about 310.degree. to 550.degree. C. In this reaction, the nitro groups are selectively replaced by bromine; further bromination of the aromatic system beyond that does not take place.