Patents by Inventor Hans Kiefer

Hans Kiefer 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: 4701546
    Abstract: 2-(N-Formylamino)-propionitrile is prepared by reacting acrylonitrile with formamide in the presence of a basic compound by a process in which the basic compound used is a tertiary nitrogen base.
    Type: Grant
    Filed: May 23, 1986
    Date of Patent: October 20, 1987
    Assignee: BASF Aktiengesellschaft
    Inventors: Wolfgang Bewert, Hans Kiefer
  • Patent number: 4565894
    Abstract: Ionones are prepared by cyclization of pseudoionone with concentrated sulfuric acid in the presence of an organic solvent or diluent, while cooling, and by dilution of the reaction mixture with water, by a continuous process in which the pseudoionone is combined with an aliphatic or cycloaliphatic hydrocarbon which boils at 25.degree.-65.degree. C. under the reaction conditions, or an aliphatic chlorohydrocarbon, and the sulfuric acid, with thorough mixing and evaporative cooling by partial or complete vaporization of the solvent present in the reaction mixture, combination being effected so that the temperature of the reaction mixture is from 25.degree. to 65.degree. C. and the residence time of this mixture before it is diluted with water is from 0.5 to 20, preferably from 0.1 to 5, seconds.The novel process can be used to prepare .alpha.- and .beta.-ionone in a technically simple and advantageous manner and in very good yields.
    Type: Grant
    Filed: August 6, 1984
    Date of Patent: January 21, 1986
    Assignee: BASF Aktiengesellschaft
    Inventors: Otto Hertel, Hans Kiefer, Lothar Arnold
  • Patent number: 4482492
    Abstract: Vitamin K.sub.3 (I; 2-methylnaphtho-1,4-quinone), vitamin K.sub.4 (IIa; 2-methyl-1,4-dihydroxynaphthalene) and vitamin K.sub.4 diacetate (IIb) are prepared by reacting 1-acetoxy-buta-1,3-diene (IV) with methylbenzoquinone (V) to give the novel compounds IIIa and IIIb ##STR1## and, for the preparation of IIa, deacetylating these compounds, or, for the preparation of IIb, deacetylating these compounds and at the same time reacting them with acetic anhydride, or, for the preparation of I, deacetylating these compounds and at the same time oxidizing them.
    Type: Grant
    Filed: October 18, 1982
    Date of Patent: November 13, 1984
    Assignee: BASF Aktiengesellschaft
    Inventor: Hans Kiefer
  • Patent number: 4454587
    Abstract: Alpha and beta particles containing samples are detected to generate deter pulses wherein the leading edge of the pulses rise particle specifically almost constantly during a predetermined time with the slope of the pulses generated by alpha particles being substantially greater than the slope of the pulses generated by the beta particles. This physical phenomenon which is substantially independent of the energy of the particles is utilized for discrimination to determine which type of particle produced the pulse.The linear starting region of the leading edge of the detector pulse is time discriminated in the nanosecond range. During the time given by the time discrimination, the detector pulses of alpha particles reach substantially higher amplitude values than the detector pulses generated by beta particles.
    Type: Grant
    Filed: July 14, 1981
    Date of Patent: June 12, 1984
    Assignee: Kernforschungszentrum Karlsruhe Gesellschaft mit beschrankter Haftung
    Inventors: Hans Kiefer, Hans-Gerd Rober, Bernd Reinhardt
  • Patent number: 4400621
    Abstract: A device for simultaneously detecting alpha and beta particles which comprises a detector element, amplification means coupled to the output of the detector element and measuring means coupled to the output of the amplification means. The alpha and beta particles which impinge on the detector element exhibit different ionization densities, and this results in a voltage being generated at the output of the amplification means which has a rise time and amplitude corresponding to the type of particle impinging on the detector element. The measuring means measures at least the rise time of the voltage at the output of the amplification means, the rise time being different for the alpha and beta particles and providing a means for distinguishing between the two types of particles.
    Type: Grant
    Filed: February 2, 1981
    Date of Patent: August 23, 1983
    Assignee: Kernforschungszentrum Karlsruhe GmbH
    Inventors: Hans Kiefer, Hans-Gerd Rober
  • Patent number: 4218568
    Abstract: Formic acid is prepared by hydrolyzing methyl formate, the hydrolysis being carried out in the presence of from 0.5 to 3.0 moles, per mole of methyl formate, of a base which contains tertiary nitrogen atoms, boils at not less than 180.degree. C. under atmospheric pressure and has a pKa from 4 to 9, N-substituted imidazole derivatives being the preferred bases.
    Type: Grant
    Filed: September 26, 1978
    Date of Patent: August 19, 1980
    Assignee: BASF Aktiengesellschaft
    Inventors: Heinz Hohenschutz, Johannes E. Schmidt, Hans Kiefer
  • Patent number: 4217460
    Abstract: Carboxylic acids of the general formula IR.sup.1 -COOH Iwhere R.sup.1 is hydrogen, methyl, ethyl or vinyl, are isolated from their dilute aqueous solutions by extraction followed by distillation of the mixtures obtained, the extractant used being a secondary amide of the general formula II ##STR1## where R.sup.2 and R.sup.3 are alkyl, cycloalkyl, aryl or aralkyl or conjointly are 1,4- or 1,5-alkylene, in each case of not more than 8 carbon atoms, with the proviso that the sum of the carbon atoms of R.sup.2 and R.sup.3 is from 7 to 14 and that only one of these radicals is aryl, and where R.sup.4 is one of the radicals R.sup.1.
    Type: Grant
    Filed: April 6, 1978
    Date of Patent: August 12, 1980
    Assignee: BASF Aktiengesellschaft
    Inventors: Heinz Hohenschutz, Johannes E. Schmidt, Hans Kiefer
  • Patent number: 4134915
    Abstract: Formamide is manufactured continuously from methyl formate and gaseous ammonia. The reaction is carried out in a reactor at from 30 to 90.degree. C, from 5 to 20% by volume of the reactor output is drawn off continuously and fed to the formamide working-up stage, and the remainder of the reactor output is cooled, in an external circuit maintained by means of a pump, to from 25 to 60.degree. C and is mixed with the amount of fresh methyl formate required for steady-state operation, after which the appropriate amount of gaseous ammonia is introduced into the stream of liquid through a jet, by the sucking-jet principle, and the stream of liquid is recycled to the reactor.
    Type: Grant
    Filed: May 5, 1977
    Date of Patent: January 16, 1979
    Assignee: BASF Aktiengesellschaft
    Inventors: Heinz Hohenschutz, Max Strohmeyer, Manfred Herr, Hans Kiefer
  • Patent number: 4038311
    Abstract: The production of N-(1-alkenyl)-carbamyl chlorides by reaction of a Schiff base with phosgene, and the new N-(1-alkenyl)-carbamyl chlorides themselves. The new compounds which can be prepared by the process of the invention are valuable starting materials for the production of coating intermediates, plastics, paints and plant protection agents.One preferred group of compounds available from said process are the N-vinyl compounds of the formula ##STR1## in which R.sup.1 is cyclohexyl, cyclooctyl, norbornyl, tetrahydrodicyclopentadienyl, n-hexyl, n-octyl, 2-ethylhexyl or phenyl. Another preferred group of compounds are the N-vinyl-N-t-alkylcarbamyl chlorides of 4 to 6 carbon atoms in the tertiary alkyl group, especially N-vinyl-N-t-butylcarbamyl chloride.
    Type: Grant
    Filed: December 16, 1974
    Date of Patent: July 26, 1977
    Assignee: BASF Aktiengesellschaft
    Inventors: Hans Kiefer, Herbert Naarmann
  • Patent number: 3983010
    Abstract: Formic acid is isolated from mixtures containing formic acid, methyl formate, methanol and water by fractional distillation, the mixture being fed into the upper half of the distillation column and 5 to 15 theoretical plates being maintained above the feed point and 10 to 25 theoretical plates below the feed point. The formic acid is withdrawn at the bottom end of the column as an azeotrope with water, the azeotrope being in the liquid state or preferably in the vapor state.
    Type: Grant
    Filed: February 6, 1975
    Date of Patent: September 28, 1976
    Assignee: BASF Aktiengesellschaft
    Inventors: Konrad Rauch, Hans Kiefer, Dieter Hesse, Max Strohmeyer, Heinz Hohenschutz
  • Patent number: 3969510
    Abstract: Method of controlling fungi with substituted benzoic acid derivatives, in particular substituted benzanilides.
    Type: Grant
    Filed: June 9, 1975
    Date of Patent: July 13, 1976
    Assignee: Badische Anilin- & Soda-Fabrik Aktiengesellschaft
    Inventors: Hans Osieka, Ernst-Heinrich Pommer, Hans Kiefer