Patents by Inventor Guido Steffan

Guido Steffan 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: 6822095
    Abstract: The present invention relates to a process for preparing 4,6-dichloropyrimidine by reaction of 4-chloro-6-hydroxypyrimidine with an acid chloride.
    Type: Grant
    Filed: December 19, 2001
    Date of Patent: November 23, 2004
    Assignee: Bayer Aktiengesellschaft
    Inventors: Franz-Josef Mais, Günther Cramm, Alexander Klausener, Guido Steffan
  • Patent number: 6562970
    Abstract: The present invention relates to a process for preparing 4-chloro-6-hydroxypyrimidine from 4-chloro-6-methoxypyrimidine.
    Type: Grant
    Filed: December 20, 2001
    Date of Patent: May 13, 2003
    Assignee: Bayer Aktiengesellschaft
    Inventors: Franz-Josef Mais, Günther Cramm, Alexander Klausener, Guido Steffan
  • Patent number: 6525198
    Abstract: The invention relates to a method for the preparation of 4,6-dichloropyrimidine by reacting 4-chloro-6-methoxypyrimidine with at least one sulphur-containing chlorinating agent selected from the group consisting of SCl2, SOCl2, and SO2Cl2 in the presence of at least one phosphorus compound having the formula R3P═Yn  (1), in which R represents C1-C10-alkyl or C6-C10-aryl, each of which may optionally be substituted by up to five identical or different substituents selected from the group consisting of fluorine, chlorine, bromine, C1-C4-alkyl, and C1-C4-alkoxy, Y represents oxygen or sulphur, and n represents zero or 1.
    Type: Grant
    Filed: February 7, 2002
    Date of Patent: February 25, 2003
    Assignee: Bayer Aktiengesellschaft
    Inventors: Franz-Josef Mais, Alexander Klausener, Günther Cramm, Guido Steffan
  • Patent number: 6504059
    Abstract: Process for converting a nitrobenzene into a free aminophenol by catalytic reduction hydroxylation in the presence of an aqueous-acidic reaction medium.
    Type: Grant
    Filed: February 11, 1999
    Date of Patent: January 7, 2003
    Assignee: Bayer Aktiengesellschaft
    Inventors: Franz-Josef Mais, Albrecht Marhold, Guido Steffan
  • Patent number: 6455725
    Abstract: The invention relates to substituted cinnamic acids and cinnamic acid esters of formula (I), wherein X represents F, Cl or J and R1 and R2 are the same or different and represent hydrogen, an optionally substituted C1-C10-alkyl radical or an optionally substituted benzyl radical. Substituted indanone carboxylic acid esters are produced using said substituted cinnamic acid and cinnamic acid ester in a technically simple and non-dangerous manner as far as safety is concerned.
    Type: Grant
    Filed: February 13, 2001
    Date of Patent: September 24, 2002
    Assignee: Bayer Aktiengesellschaft
    Inventors: Walter Lange, Joachim Komoschinski, Guido Steffan, Ernst Kysela
  • Patent number: 6441171
    Abstract: The invention relates to a method for the preparation of 4,6-dichloropyrimidine by reacting 4-chloro-6-methoxypyrimidine with phosgene as chlorinating agent in the presence of a nitrogen-containing auxiliary.
    Type: Grant
    Filed: January 24, 2002
    Date of Patent: August 27, 2002
    Assignee: Bayer Aktiengesellschaft
    Inventors: Franz-Josef Mais, Günther Cramm, Alexander Klausener, Guido Steffan
  • Patent number: 6441170
    Abstract: The present invention relates to a process for preparing 4,6-dichloro-pyrimidine by reaction of 4-chloro-6-methoxypyrimidine with an acid chloride in the presence of a hydrogen halide.
    Type: Grant
    Filed: December 19, 2001
    Date of Patent: August 27, 2002
    Assignee: Bayer Akitnegesellschaft
    Inventors: Franz-Josef Mais, Günther Cramm, Alexander Klausener, Guido Steffan
  • 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: 6369259
    Abstract: Crystals with an average crystal size of ≦10 &mgr;m comprising compounds of the formula Ia and/or IIa A process for making said crystals.
    Type: Grant
    Filed: September 22, 2000
    Date of Patent: April 9, 2002
    Assignee: Bayer Aktiengesellschaft
    Inventors: Guido Steffan, Georg Hardenbicker
  • 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: 6296788
    Abstract: Grignard reagents which contain a protected aldehyde function are obtained in a particularly advantageous manner from a halogenated aldehyde by reaction with a secondary monoamine to give an open-chain aminal, and conversion of the latter into a Grignard reagent using metallic magnesium. The invention also relates to novel Grignard reagents of this type.
    Type: Grant
    Filed: July 13, 2000
    Date of Patent: October 2, 2001
    Assignee: Bayer Aktiengesellschaft
    Inventors: Guido Giffels, Guido Steffan
  • Patent number: 6294502
    Abstract: The invention discloses a novel thermally-responsive record material comprising a support having coated thereon a thermally sensitive color forming composition comprising a chromogenic material, an acidic developer material and a certain carbamate component that does not include dodecyl-N-phenylcarbamate. The novel record material displays enhanced image intensity or improved thermal response.
    Type: Grant
    Filed: May 14, 1999
    Date of Patent: September 25, 2001
    Assignee: Bayer Aktiengesellschaft
    Inventors: Mark Robert Fisher, John Charles DeBraal, Guido Steffan, Peter P. Wenzl
  • Patent number: 6197964
    Abstract: The process according to the invention can be illustrated by way of example by the following equation: The monosodium salt of the 3-cyano-2-hydroxy-5-fluoropyrid-6-one (cf. Formula (I)) and/or tautomers thereof are preferably employed in the process according to the invention. The use of a basic catalyst enables significantly lower amounts of chlorinating agent to be employed in the chlorination according to the invention than is necessary, for example, for chlorination of the free dihydroxy compound according to EP-A 333 020. Furthermore, the product 2,6-dichloro-5-fluoronicotinonitrile is obtained in a high purity and high yields after hydrolysis, which is not the case if the conditions according to EP-A 333 020 are applied. Basic catalysts which can be used for the process according to the invention are, for example, organic bases, for example aliphatic and aromatic amines and amides, and also inorganic bases, for example basic compounds of nitrogen and phosphorus and salts thereof.
    Type: Grant
    Filed: September 27, 1999
    Date of Patent: March 6, 2001
    Assignee: Bayer Aktiengesellschaft
    Inventors: Andreas Sattler, Guido Steffan, Bernd Griehsel
  • Patent number: 6184417
    Abstract: Acetophenones which are substituted on the aromatic ring by fluoroalkyl are prepared in a particularly advantageous, environmentally friendly and effective manner from fluoroalkylanilines and acetaldoxime by preparing from a fluoroalkylaniline a corresponding diazonium salt solution, and reacting this with acetaldoxime in the presence of at least one copper compound, without adding any buffer salts or reducing agents, carrying out the reaction at from 20 to 50° C. and in the presence of halide ions and subsequently heating to a temperature in the range from 70 to 110° C.
    Type: Grant
    Filed: November 1, 1999
    Date of Patent: February 6, 2001
    Assignee: Bayer Aktiengesellschaft
    Inventors: Wulf Kühnle, Albrecht Marhold, Guido Steffan
  • Patent number: 6162917
    Abstract: The invention relates to a process for the preparation of 4,5,6-trichloro- and 2,4,5,6-tetrachloropyrimidine starting from 3-dimethylamino-propionitrile, to its use and also to a crystalline intermediate product form.
    Type: Grant
    Filed: December 7, 1998
    Date of Patent: December 19, 2000
    Assignee: Bayer Aktiengesellschaft
    Inventors: Guido Steffan, Georg Hardenbicker
  • Patent number: 6025499
    Abstract: Nitropyrazole amides of the formula (I) ##STR1## are prepared by reacting nitropyrazole esters of the formula (II) ##STR2## with ammonia.
    Type: Grant
    Filed: March 25, 1999
    Date of Patent: February 15, 2000
    Assignee: Bayer Aktiengesellschaft
    Inventors: Lutz Heuer, Nikolaus Muller, Guido Steffan
  • Patent number: 6015771
    Abstract: The present invention discloses a novel thermally-responsive record material having coated thereon a thermally sensitive color forming composition comprising a chromogenic material, an acidic developer material and a carbamate of the formula ##STR1## wherein R is selected from alkyl, aryl or aralkyl. The alkyl moiety in each of the preceding is selected to be of from one to eight carbons. The novel record material displays enhanced image intensity or improved thermal response.
    Type: Grant
    Filed: May 22, 1998
    Date of Patent: January 18, 2000
    Assignee: Bayer Aktiengesellschaft
    Inventors: Mark Robert Fisher, John Charles DeBraal, Guido Steffan, Peter P. Wenzl
  • Patent number: 5969152
    Abstract: Nitropyrazole esters of the formula ##STR1## in which R.sup.1 represents C.sub.1 -C.sub.6 -alkyl, are prepared by nitration of the corresponding pyrazole esters. The nitropyrazole esters permit the preparation of a known nitropyrazole amide in a particularly simple and economical manner and thereby improve the preparation of active compounds which are accessible from the nitropyrazole amide.
    Type: Grant
    Filed: July 7, 1997
    Date of Patent: October 19, 1999
    Assignee: Bayer Aktiengesellschaft
    Inventors: Lutz Heuer, Nikolaus Muller, Guido Steffan
  • Patent number: 5900509
    Abstract: p-Haloalkoxyanilines are obtained from the corresponding nitrobenzenes by catalytic hydroxylation in the presence of an aqueous acidic reaction medium with the formation of a corresponding aminophenol and reaction of this aminophenol with a halogenated olefin in the presence of water and a catalytic amount of base.
    Type: Grant
    Filed: January 16, 1998
    Date of Patent: May 4, 1999
    Assignee: Bayer Aktiengesellschaft
    Inventors: Franz-Josef Mais, Albrecht Marhold, Guido Steffan
  • 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