Patents by Inventor Helmut Fiege

Helmut Fiege 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).

  • Publication number: 20040030186
    Abstract: The invention relates to a process for preparing 3,3-dimethyl-2-oxobutyric acid and salts thereof by oxidizing 3,3-dimethyl-2-hydroxybutyric acid with oxygen or oxygen-containing gases in a basic aqueous medium and in the presence of palladium catalysts and also of bismuth or bismuth compounds.
    Type: Application
    Filed: August 8, 2003
    Publication date: February 12, 2004
    Inventor: Helmut Fiege
  • Patent number: 6500988
    Abstract: The invention relates to a particularly advantageous method for producing aryl thiols through the catalytic hydrogenation of diaryldisulphides. According to the invention, the hydrogenation is carried out in a basic alcoholic medium.
    Type: Grant
    Filed: April 19, 2000
    Date of Patent: December 31, 2002
    Assignee: Bayer Aktiengesellschaft
    Inventors: Friedrich-Wilhelm Ullrich, Helmut Fiege
  • Patent number: 6433228
    Abstract: 2-Halogenoindan-1-ones are prepared in an advantageous manner by converting anilines into diazonium salts and these, with acrylic compounds, into 3-phenyl-1-halogenoproprionic acid derivatives, and latter are cyclized.
    Type: Grant
    Filed: February 18, 2000
    Date of Patent: August 13, 2002
    Assignee: Bayer Aktiengesellschaft
    Inventors: Joachim Komoschinski, Helmut Fiege, Guido Steffan, Klaus-Christian Paetz
  • Patent number: 6355827
    Abstract: In a particularly advantageous process for producing 2-cyanoindan-1-ones from 2-halogenated indan-1-ones by reaction with a cyanide salt, the cyanide salt is dissolved in a dipolar aprotic solvent or in a water-miscible ether and 2-halogenated indan-1-one is metered into this solution.
    Type: Grant
    Filed: February 18, 2000
    Date of Patent: March 12, 2002
    Assignee: Bayer Aktiengesellschaft
    Inventors: Joachim Komoschinski, Helmut Fiege, Guido Steffan
  • Patent number: 6271415
    Abstract: The invention relates to novel S-(4-biphenyl)-thiosulfuric acids and their salts, to a method for producing them from S-(4-biphenyl)-thiosulfinic acids and their salts, and to a method for producing 4-mercaptobiphenyls from the S-(4-biphenyl)-thiosulfuric acids and their salts.
    Type: Grant
    Filed: April 19, 2000
    Date of Patent: August 7, 2001
    Assignee: Bayer Aktiengesellschaft
    Inventors: Friedrich-Wilhelm Ullrich, Helmut Fiege, Wolfgang Eymann
  • Patent number: 6133480
    Abstract: N-Phenyl-1-naphthylamine can be prepared by reaction of aniline and 1-naphthylamine in the liquid phase at 100-400.degree. C. under normal pressure, a catalyst mixture comprising boron and fluorine being employed. Such catalyst mixtures can be obtained, for example, by reaction of hydrogen fluoride, boric acid and aniline and/or 1-naphthylamine. The catalyst is recovered and can be employed again. The reaction can be carried out discontinuously or continuously.
    Type: Grant
    Filed: December 10, 1998
    Date of Patent: October 17, 2000
    Assignee: Bayer Aktiengesellschaft
    Inventors: Horst Behre, Helmut Fiege, Wolfgang Eymann, Frank Arndt, Rudolf Wiemers, Alexander Klausener
  • Patent number: 6093852
    Abstract: The invention concerns 4,6-diamino-resorcinol which is prepared in the form of its dihydrochloride by catalytic hydrogenation of 1,3-benzyloxy-4,6-dinitrobenzene on a noble metal contact in a two-phase mixture of dilute aqueous hydrochloric acid and an organic solvent which is not miscible with dilute aqueous hydrochloric acid. This process is carried out at a pressure of between 1 and 200 bar and a temperature of between 0 and 200.degree. C.
    Type: Grant
    Filed: November 17, 1998
    Date of Patent: July 25, 2000
    Assignee: Bayer Aktiengesellschaft
    Inventors: Horst Behre, Helmut Fiege, Heinz Ulrich Blank, Wolfgang Eymann
  • Patent number: 6002041
    Abstract: Particularly pure di-C.sub.1 -C.sub.4 -alkyl 5-nitro-isophthalates are obtained in good yield and in a simple process by dissolving 5-nitro-isophthalic acid in a mixture of a C.sub.1 -C.sub.4 -alkyl alcohol and a solvent which is miscible or only partially miscible with water, heating in the presence of a strong acid, thus forming a second, aqueous phase, crystallizing out, after the esterification reaction has ended, the di-C.sub.1 -C.sub.4 -alkyl 5-nitro-isophthalate formed from the organic phase by cooling and removing the aqueous phase before or after the di-C.sub.1 -C.sub.4 -alkyl 5-nitro-isophthalate is separated off.
    Type: Grant
    Filed: May 6, 1998
    Date of Patent: December 14, 1999
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gunter Rauchschwalbe, Bernhard Beitzke, Helmut Fiege
  • Patent number: 5998628
    Abstract: Preparations consisting of 5 to 90%, relative to the total weight of the preparations, of mainly neutralized 1-hydroxy-benzotriazole of the formula ##STR1## in which R.sup.1 and R.sup.2, independently of one another, represent hydrogen or methyl andM.sup..sym. is one equivalent of an alkali metal or alkaline earth metal cation or H.sup..sym., whereby M.sup..sym. is present in the range of 85-100 equivalent-% as alkali metal or alkaline earth metal cation and in the range of 15-0 equivalent-% as H.sup..sym.,and the remainder to 100% of water, whereby the water containing preparations have a pH value of from 3 to 11 are nonexplosive and can be handled without danger.For the preparation, unsubstituted 1-hydroxy-benzotriazole is neutralized with an aqueous solution or suspension of a hydroxide, bicarbonate or carbonate of an alkali metal or alkaline earth metal. These preparations may be present as solutions, suspensions or pastes.
    Type: Grant
    Filed: March 16, 1998
    Date of Patent: December 7, 1999
    Assignee: Bayer Aktiengesellschaft
    Inventors: Ferdinand Hagedorn, Helmut Fiege
  • Patent number: 5922874
    Abstract: N-aryl-N'-alkyl-piperazines are obtained in a particularly simple manner, in good yields and in short reaction times when an aniline is reacted under pressure with an N-alkyl-bishydroxyethyl-amine in the presence of a strong acid.
    Type: Grant
    Filed: July 24, 1998
    Date of Patent: July 13, 1999
    Assignee: Bayer Atkiengesellschaft
    Inventors: Joachim Komoschinski, Helmut Fiege, Bernhard Beitzke
  • Patent number: 5911962
    Abstract: Impure POCl.sub.3 is purified by distillation in the presence of high-boiling nitrogen compounds from the group consisting of the substituted pyridines and pyrimidines, the open-chain and cyclic aliphatic amines, the open-chain and cyclic amidines, the guanidines and the aromatic amines.
    Type: Grant
    Filed: July 10, 1998
    Date of Patent: June 15, 1999
    Assignee: Bayer Aktiengesellschaft
    Inventors: Franz-Josef Mais, Helmut Fiege
  • Patent number: 5872283
    Abstract: Halogenated aromatic carboxylic acids are decarboxylated by heating them in the presence of water at temperatures of 80.degree. to 180.degree. C. and in the presence of water and other acids at temperatures above 80.degree. C.
    Type: Grant
    Filed: June 26, 1997
    Date of Patent: February 16, 1999
    Assignee: Bayer Aktiengesellschaft
    Inventors: Stefan Antons, Guido Steffan, Helmut Fiege
  • Patent number: 5872300
    Abstract: 2-Amino-6-chlorophenyl-alkylsulfanes are prepared in a particularly advantageous manner by hydrogenating 2-chloro-6-nitrophenyl-alkylsulfanes catalytically in the presence of a solvent without the addition of a further sulfur compound, and the novel compound 2-amino-6-chlorophenyl-isopropylsulfane is provided.
    Type: Grant
    Filed: November 14, 1996
    Date of Patent: February 16, 1999
    Assignee: Bayer Aktiengesellschaft
    Inventors: Ferdinand Hagedorn, Wolfgang Kiel, Helmut Fiege
  • Patent number: 5869735
    Abstract: Process for the preparation of alkyl aryl ethers containing carboxyl groups which are suitable for the preparation of colour film couplers, or derivatives thereof, by reaction of aromatic alcohols with alkyl halides containing carboxyl groups or derivatives thereof and basic alkali metal or alkaline earth metal compounds, characterized in that the reaction is carried out in the melt of the aromatic alcohol.
    Type: Grant
    Filed: October 11, 1996
    Date of Patent: February 9, 1999
    Assignee: Bayer Aktiengesellschaft
    Inventors: Stefan Antons, Erich Hammerschmidt, Heinz Ulrich Blank, Helmut Fiege, Heinz-Gerd Hartges
  • Patent number: 5859296
    Abstract: Hydroxypivalic acid is obtained from aqueous solutions by removal of the water by azeotropic distillation and subsequent crystallization from a solvent mixture which is composed of a polar and a non-polar component. The distillation is carried out under reduced pressure and at a maximum bottom temperature of 90.degree. C., until a residual water content of at least 0.1% of the total weight of the resulting solution is achieved.
    Type: Grant
    Filed: August 5, 1997
    Date of Patent: January 12, 1999
    Assignee: Bayer Aktiengesellschaft
    Inventors: Karl Heinz Neumann, Dieter Heitkamp, Helmut Fiege
  • Patent number: 5847234
    Abstract: 4-Hydroxybiphenyl is obtained in non-thixotropic form if a reaction mixture which is obtained by alkaline hydrolysis of biphenyl-4-sulfonic acid and contains 4-hydroxybiphenyl is heated at elevated pressure at above 115.degree. C. and at a pH from 0 to below 6.5.
    Type: Grant
    Filed: June 12, 1997
    Date of Patent: December 8, 1998
    Assignee: Bayer Aktiengesellschaft
    Inventors: Horst Behre, Helmut Fiege, Gunter Rauchschwalbe
  • Patent number: 5847236
    Abstract: 2-Chloro-4-methylphenol is prepared by reacting 4-methylphenol with a chlorinating agent in the presence of a catalyst system of one or more Lewis acids in a total amount of 0.1-10% by weight and one or more diaryl sulphides in a total amount of 0.1-10% by weight, all based on the amount of 4-methylphenol. The reaction temperature is 0.degree.-100.degree. C. The chlorinating agent is used in an amount of 0.5-1.5 mol per mole of 4-methylphenol. The reaction can be carried out until virtually complete consumption of the 4-methylphenol, high isomeric selectivity and high stage selectivity being observed.
    Type: Grant
    Filed: September 25, 1996
    Date of Patent: December 8, 1998
    Assignee: Bayer Aktiengesellschaft
    Inventors: Franz-Josef Mais, Helmut Fiege
  • Patent number: 5808141
    Abstract: The new process for preparing 4,4'-dinitrostilbene-2,2'-disulphonic acid and salts thereof by oxidation of 4-nitrotoluene-2-sulphonic acid with an oxidant in the presence of strong bases is characterized in that the oxidation is carried out in a mixture of water and an organic solvent selected from the group consisting of alcohols, ethers and mixtures thereof.
    Type: Grant
    Filed: July 21, 1997
    Date of Patent: September 15, 1998
    Assignee: Bayer Aktiengesellschaft
    Inventors: Albert Schnatterer, Helmut Fiege
  • Patent number: 5801276
    Abstract: Hydroxypivalic acid can be prepared by oxidation of hydroxypivalaldehyde with hydrogen peroxide by metering the hydrogen peroxide, as the oxidizing agent, into an aqueous hydroxypivalaldehyde reservoir in the temperature range from 60.degree. to 80.degree. C. such that a hydrogen peroxide concentration of 4% by weight, based on the total weight of the reaction mixture, is not exceeded, and ending the addition of hydrogen peroxide as soon as the concentration of hydroxypivalaldehyde in the reaction mixture falls below 1% by weight.
    Type: Grant
    Filed: August 5, 1997
    Date of Patent: September 1, 1998
    Assignee: Bayer Aktiengesellschaft
    Inventors: Karl-Heinz Neumann, Winfried Joentgen, Dieter Heitkamp, Helmut Fiege
  • Patent number: 5801284
    Abstract: Process for preparing haloaromatic amines by catalytic hydrogenation of the corresponding halonitroaromatic compounds, characterized in that iron-containing Raney nickel is used as catalyst, where the haloaromatic amines prepared can be used for the synthesis of photographic couplers which are useful in photographic emulsions or elements.
    Type: Grant
    Filed: February 5, 1997
    Date of Patent: September 1, 1998
    Assignee: Bayer Aktiengesellschaft
    Inventors: Franz-Josef Mais, Klaus-Christian Paetz, Helmut Fiege, Heinz Ulrich Blank, Dieter Brueck, Wolf Mehl