Patents by Inventor Gunter Siegemund

Gunter Siegemund has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5118874
    Abstract: Compounds of the formula ##STR1## in which, independently of one another, each R is OH or lower alkyl having 1-4 carbon atoms and each R' is hydrogen or lower alkyl having 1-4 carbon atoms, are prepared by the condensation of partially fluorinated aromatic hydrocarbons in the presence of hydrogen fluoride or by the reductive coupling of partially fluorinated aromatic compounds. The compounds are used as a starting material for the preparation of partially fluorinated polycondensates.
    Type: Grant
    Filed: June 20, 1991
    Date of Patent: June 2, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Wolfgang Appel, Gunter Siegemund
  • Patent number: 5110983
    Abstract: Compounds of the formula I ##STR1## can be prepared by various process steps from 2-(4-methylphenyl)-2-hexafluoroisopropanol.Hexafluoroisopropyl-containing monomers are important starting compounds in the preparation of linear polycarboxamides and polycarboximides.
    Type: Grant
    Filed: March 22, 1990
    Date of Patent: May 5, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Jurgen Lau, Gunter Siegemund, Freimund Rohrscheid
  • Patent number: 5087748
    Abstract: A continuous process for the preparation of perfluorinated carbonyl fluorides from hexafluoropropene oxide (HFPO), in which HFPO is continuously oligomerized in a catalyst solution in devices which allow separation of the heavy product phase from the catalyst phase during the reaction, is described. Different oligomer distributions can be achieved by choice of the catalyst and different operating temperatures. The reaction itself takes place always in the substantial absence of the product which is formed, and achieves a considerable saving in time.
    Type: Grant
    Filed: January 11, 1990
    Date of Patent: February 11, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Manfred Finke, Gunter Siegemund, Heinz Strutz
  • Patent number: 5081315
    Abstract: Compounds of the formula ##STR1## in which A represents the radicals ##STR2## in which R.sup.1 and R.sup.2 are different from one another and denote hydrogen, --NO.sub.2 or --NH.sub.2, R.sup.3 is hydrogen or halogen, X represents --NO.sub.2 or --NH.sub.2, with the proviso that R.sup.1 is hydrogen, if R.sup.2 is --NO.sub.2 or --NH.sub.2 and R.sup.2 is hydrogen, if R.sup.1 is --NO.sub.2 or --NH.sub.2.The compounds are prepared from 4,4'-bis[2-(4-hydroxyphenyl)hexafluoroisopropyl]diphenyl ether by nitration or reaction with nitrobenzenes followed by reduction of the nitro groups. They are used for the preparation of high-temperature-resistant polycondensates.
    Type: Grant
    Filed: August 20, 1990
    Date of Patent: January 14, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Jurgen Lau, Gunter Siegemund
  • Patent number: 5028728
    Abstract: Process for the preparation of compounds of the formula I ##STR1## in which R.sup.1 denotes NO.sub.2 or NH.sub.2 andR.sup.2 denotes a radical of a cycloaliphatic amine having 6 ring atoms and a total of not more than 10 carbon atoms, a benzylamine radical, an aniline radical which contains up to three substituents belonging to the group comprising alkyl, alkoxy, chlorine and bromine, not more than two of which can be halogen and not more than one of which can be alkoxy, and contains a total of not more than 10 carbon atoms, or which contains a trifluoromethyl or phenoxy group, or R.sup.2 denotes the phenylmercapto radical or the benzylmercapto radical, compounds of the formula I in which R.sup.1 is NO.sub.2 or NH.sub.2 and R.sup.
    Type: Grant
    Filed: April 27, 1990
    Date of Patent: July 2, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Klaus-Albert Schneider, Gunter Siegemund
  • Patent number: 5017719
    Abstract: The invention relates to esters of the general formula IV ##STR1## wherein R.sup.1 to R.sup.5 represent at least one of the substituents hydrogen, halogen, alkyl, alkoxy, alkylthio and perfluorinated alkyl, each having from 1 to 6 carbon atoms and n is 0 or an integer from 1 to 5.The invention also relates to a process for the preparation of arylbisperfluoro alkyl compounds of the general formula VIII ##STR2## wherein R.sup.1 to R.sup.
    Type: Grant
    Filed: July 28, 1988
    Date of Patent: May 21, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Alfred Kruse, Gunter Siegemund, Ingo Ruppert, deceased
  • Patent number: 5004797
    Abstract: Partly fluorinated carboxylic acids and derivatives thereof, processes for their preparation and their use. Partly fluorinated carboxylic acids, in particular a partly fluorinated dicarboxylic acid, its acid chloride and partly fluorinated tetracarboxylic acids having various fluorine contents and their dianhydrides are obtained by atmospheric oxidation in an acid medium and at elevated temperature in the presence of a catalyst mixture of at least two heavy metal compounds and bromide ions. The compounds are used for the preparation of polycondensates and linear polycarboxylic acid amides and -carboxylic acid esters.
    Type: Grant
    Filed: November 23, 1988
    Date of Patent: April 2, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Freimund Rohrscheid, Gunter Siegemund, Jurgen Lau
  • Patent number: 4992593
    Abstract: A compound of the formula ##STR1## in which independently of one another R is equal to OH or lower alkyl having 1 to 4 carbon atoms, R' is equal to hydrogen or lower alkyl having 1 to 4 carbon atoms, processes for their preparation and their use as starting material in the preparation of partially fluorinated polycondensates.
    Type: Grant
    Filed: November 23, 1988
    Date of Patent: February 12, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventor: Gunter Siegemund
  • Patent number: 4978790
    Abstract: Compounds of the formula ##STR1## in which A represents the radicals ##STR2## in which R.sup.1 and R.sup.2 are different from one another and denote hydrogen, --NO.sub.2 or --NH.sub.2, R.sup.3 is hydrogen or halogen, X represents --NO.sub.2 or --NH.sub.2, with the proviso that R.sup.1 is hydrogen, if R.sup.2 is --NO.sub.2 or --NH.sub.2 and R.sup.2 is hydrogen, if R.sup.1 is --NO.sub.2 or --NH.sub.2.The compounds are prepared from 4,4'-bis[2-(4-hydroxyphenyl)hexafluoroisopropyl]diphenyl ether by nitration or reaction with nitrobenzenes followed by reduction of the nitro groups. They are used for the preparation of high-temperature-resistant polycondensates.
    Type: Grant
    Filed: November 23, 1988
    Date of Patent: December 18, 1990
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Jurgen Lau, Gunter Siegemund
  • Patent number: 4973749
    Abstract: A process for the preparation of the dimer of hexafluoropropene oxide (HFPO), in which the HFPO is dimerized in an aprotic polar solvent in the presence of a catalyst mixture, is described. The catalyst mixture is composed of a metal salt of the elements of the 1st transition metal series of the periodic table and of a tertiary diamine. By bringing in a molar ratio of metal salt to tertiary diamine in the range from 2:1 to 1:2, in particular 1:1, the selectivity for the dimeric compound is greatest, with high yields of the dimer being obtained.
    Type: Grant
    Filed: January 11, 1990
    Date of Patent: November 27, 1990
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Gunter Siegemund, Manfred Finke
  • Patent number: 4968845
    Abstract: A process for the preparation of halogen-containing aromatic compounds of the formula ##STR1## wherein Hal represents fluorine, chlorine or bromine and Z represents an aromatic group which comprises reacting a halobenzene of the formula C.sub.6 H.sub.5 Hal (II) under anhydrous conditions with a halide of a bisacid having the formula Hal-CO-Z-CO-Hal (III) in a molar ratio of at least 2:1 in the presence of a haloalkane sulfonic acid of the formula Y(C.sub.n X.sub.2n)SO.sub.3 H (IV), in formulae II and III Hal and Z having the afore-mentioned meaning and Y representing fluorine or hydrogen, X at least one of fluorine and chlorine, but at least one X being fluorine, and n being an integer of from 1 to 10.The said bis-(4-halobenzoyl) compounds being useful monomers for chemically resistant plastics which are still resistant even at high temperatures.
    Type: Grant
    Filed: March 7, 1989
    Date of Patent: November 6, 1990
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Joachim Hackenbruch, Theodor Papenfuhs, Klaus Warning, Gunter Siegemund
  • Patent number: 4968848
    Abstract: A process for the preparation of perfluoroalkyl compounds which comprises reacting a perfluoroalkyl-trimethylsilane of the general formula (CH.sub.3).sub.3 Si-C.sub.n F.sub.2n+1 (I), wherein the group C.sub.n F.sub.2n+1 represents a perfluoroalkyl group having from 1 to 6 carbon atoms, with a carbonyl compound of the general formula F.sup.1 --CO--R.sup.2 (II), wherein R.sup.1 represents a hydrocarbon group or hydrogen and R.sup.2 represents a hydrocarbon group, a perfluoroalkyl group or a perfluoroaryl group, but wherein R.sup.1 and R.sup.2 together may also be part of an alicyclic ring system, in the presence of a salt-like fluoride--which is at least partially soluble in the reaction medium--as a catalyst to yield a silylether of the formula ##STR1## and isolating this compound or hydrolyzing it to yield an alcohol of the formula IV ##STR2## The invention also relates to pentafluoroethyl trimethylsilane (CH.sub.3).sub.3 Si--CF.sub.2 CF.sub.3 and a process for the preparation of this compound.
    Type: Grant
    Filed: February 21, 1989
    Date of Patent: November 6, 1990
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Alfred Kruse, Gunter Siegemund, Axel Schumann
  • Patent number: 4966987
    Abstract: 1-Arylalkoxy-tris(dialkylamino)phosphonium salts of the formula I ##STR1## wherein the substituents R.sup.1 to R.sup.5 are equal or different and represent hydrogen, alkyl having from 1 to 6 carbon atoms which may be perfluorinated, halogen, alkoxy or alkylthio, each having from 1 to 6 carbon atoms, Y represents hydrogen or a perfluoroalkyl group C.sub.n F.sub.2n+1 having from 1 to 6 carbon atoms, X represents bromine or iodine and "Alkyl" represents an alkyl group of 1 to 3 carbon atoms, at most 3, preferably at most 2, of the groups R.sup.1 to R.sup.5 having a meaning other than hydrogen and the alkyl, alkoxy and alkylthio substituents attached to the aromatic nucleus altogether containing preferably at most 6 carbon atoms, in particular at most 4 carbon atoms.
    Type: Grant
    Filed: January 17, 1989
    Date of Patent: October 30, 1990
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Alfred Kruse, Gunter Siegemund, Axel Schumann, Ingo W. Ruppert, deceased
  • Patent number: 4924014
    Abstract: A process for the preparation of halogen-containing aromatic compounds of the formula I ##STR1## wherein Hal represents halogen,R represents H, C.sub.1 -C.sub.3 -alkyl, phenyl, halogen or trifluoromethyl,Y represents CO or SO.sub.2 andZ represents an aromatic or heteroaromatic group, andY-Z-Y together may also be CO or SO.sub.2, which comprises reacting a haloaromatic compound of the formula RC.sub.6 H.sub.4 Hal (II) with a halide of a bisacid having the formula Hal-Y-Z-Y-Hal (III) in a molar ratio of at least 2:1 in the presence of hydrogen fluoride and or boron trifluoride, in formulae II and III Hal, R, Y and Z having the aforementioned meaning.
    Type: Grant
    Filed: February 28, 1989
    Date of Patent: May 8, 1990
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Andreas Fuss, Gunter Siegemund
  • Patent number: 4922019
    Abstract: The invention relates to compounds of the formula ##STR1## wherein R.sup.1 is hydrogen or an acyl group in which a non-aromatic hydrocarbon group of 1 to 6 carbon atoms is attached to the CO-group and R.sup.2 is H or NO.sub.2, if R.sup.1 is an acyl group, or is NO.sub.2, if R.sup.1 is hydrogen.
    Type: Grant
    Filed: June 29, 1988
    Date of Patent: May 1, 1990
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Jurgen Lau, Gunter Siegemund
  • Patent number: 4874557
    Abstract: The invention relates to a process for the preparation of perfluorinated carbonyl fluorides of the formula ##STR1## by oligomerization of hexafluoropropene oxide in the presence of a catalyst. The catalyst comprises a mixture of an alkali metal fluoride, a carboxylic acid dinitrile and a polyethylene glycol dimethyl ether.
    Type: Grant
    Filed: November 3, 1988
    Date of Patent: October 17, 1989
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Alfred Kruse, Gunter Siegemund, Werner Schwertfeger
  • Patent number: 4835318
    Abstract: A process for the preparation of arylperfluoroalkyl ketones of the general formula I ##STR1## wherein R.sup.1 and R.sup.5 represent at least one of the substituents hydrogen, halogen, alkyl, alkoxy, alkylthio and perfluorinated alkyl, each having from 1 to 6 carbon atoms and n is an integer from 1 to 6, which comprises reacting an aryl carbonyl compound having the general formula II ##STR2## wherein R.sup.1 to R.sup.5 have the above-mentioned meaning and X as a monovalent moiety represents fluorine, chlorine or bromine and as a bivalent moiety the oxygen atom of an anhydride bridge, with a perfluoroalkyl halide of the general formula C.sub.n F.sub.2n+1 -Hal (III), wherein Hal represents chlorine, bromine or iodine and n is an integer from 1 to 6, in the presence of a trisdialkyl amide of phosphorus acid of the general formula P[N(alkyl)2]3 (IV).
    Type: Grant
    Filed: July 28, 1988
    Date of Patent: May 30, 1989
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Alfred Kruse, Gunter Siegemund, Klaus Schlich, Ingo Ruppert, deceased
  • Patent number: 4778568
    Abstract: Isomer mixtures of 1,3- and 1,4-bis-(2-hydroxyhexafluoroprop-2-yl)-benzene are separated by a steam distillation in the presence of CS.sub.2. On cooling of the steam distillate, a solid precipitates which is composed mainly of the 1,4-isomer. After the solid has been separated off, an aqueous-organic liquid-phase mixture remains, the organic phase of which mainly contains the 1,3-isomer. The pure isomers are obtained by recrystallization or distillation respectively. These are mainly intermediates in the polymer field.
    Type: Grant
    Filed: July 21, 1987
    Date of Patent: October 18, 1988
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Klaus-Albert Schneider, Gunter Siegemund
  • Patent number: 4774370
    Abstract: 2,2-Bis-(3-nitrophenyl)-hexafluoropropane is prepared by oxidation of 2,2-bis-(4-methylphenyl)-hexafluoropropane to 2,2-bis-(4-carboxyphenyl)-hexafluoropropane, nitration of this compound to 2,2-bis-(4-carboxy-3-nitrophenyl)-hexafluoropropane and decarboxylation of the last-mentioned compound.The process lends to 2,2-bis-(3-nitrophenyl)-hexafluoropropane, free of isomers, in an industrially simple manner and with the use of common chemicals. The compound is a valuable intermediate in the polymer field.The 2,2-bis-(4-carboxy-3-nitrophenyl)-hexafluoropropane occurring as an intermediate in the process is novel.
    Type: Grant
    Filed: July 21, 1987
    Date of Patent: September 27, 1988
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Klaus-Albert Schneider, Gunter Siegemund
  • Patent number: 4727142
    Abstract: The invention relates to a process for the preparation of compounds of the formula I and salts or acid addition compounds thereof ##STR1## in which R denotes hydrogen, (halogenated) alkyl with the exception of CF.sub.3, a (substituted) aromatic radical, (substituted) heteroaryl, (substituted) phenoxy, (substituted) phenylthio, (substituted) phenylamino, halogen, hydroxyl, alkoxy, mercapto, (halogenated) cycloalkyl, alkylmercapto, amino, monoalkylamino or dialkylamino,R.sup.1 denotes (substituted alkyl, (substituted) phenyl or naphthyl, alkenyl, alkinyl, cycloalkyl, (substituted) benzyl or heteroaryl, and X denotes oxygen or sulfur, which comprises reacting a nitrile of the formula II with a compound of the formula IIIR--C.tbd.N (II)R.sup.
    Type: Grant
    Filed: April 18, 1986
    Date of Patent: February 23, 1988
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Andreas Fuss, Gunter Siegemund