Patents by Inventor Hans Holtschmidt

Hans Holtschmidt 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).

  • Process for the preparation of tetrachloropyrimidine
    Patent number: 4026892
    Abstract: A process for preparing tetrachloropyrimidine comprising reacting 2-cyano-1,2-(dichlorovinyl)-isocyanide-dichloride of the formulaNC -- CCl = CCl -- N = CCl.sub.2with a Friedel-Crafts compound at an elevated temperature. The resulting tetrachloropyrimidine can be used as a reactive component for the preparation of reactive dyestuffs.
    Type: Grant
    Filed: October 28, 1975
    Date of Patent: May 31, 1977
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gunther Beck, Fritz Doring, Hans Holtschmidt
  • Perchlorodiazafulvene
    Patent number: 4021443
    Abstract: Perchlorodiazafulvene having the formula ##STR1## IS PREPARED BY REACTING 2,4,5-TRICHLORO-2-TRICHLOROMETHYL-2H-imidazole having the formula ##STR2## WITH DECHLORINATING AGENTS AT ELEVATED TEMPERATURES AND IS USEFUL AS A FUNGICIDE.
    Type: Grant
    Filed: October 29, 1975
    Date of Patent: May 3, 1977
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gunther Beck, Fritz Doring, Helmut Heitzer, Hans Holtschmidt
  • Preparation of trichlorothiazole and intermediate
    Patent number: 4018784
    Abstract: Trichlorothiazole of the formula ##STR1## IS PREPARED BY REACTING 1,2,2,2-TETRACHLOROETHYL-ISOCYANIDEDICHLORIDE OF THE FORMULA ##STR2## WITH 1 TO 1.2 TIMES THE STOICHIOMETRIC AMOUNT OF SULFUR AT A TEMPERATURE OF ABOUT 150.degree. TO 250.degree. C, preferably about 170.degree. to 230.degree. C.
    Type: Grant
    Filed: December 9, 1975
    Date of Patent: April 19, 1977
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gunther Beck, Hans Holtschmidt
  • 2,5-Dichloro-thiazolo[4,5-d]thiazole and process for making same
    Patent number: 3994913
    Abstract: 2,5-Dichloro-thiazolo[4,5-d]thiazole, which is useful as a fungicide, is prepared by reacting compounds having the formula ##EQU1## wherein X.sub.1 is Cl, andX.sub.2 is H or Cl orX.sub.1 and X.sub.2 together form a C-C bondIn the temperature range of 150.degree. to 300.degree. C, with at least the stoichiometrically required amount of sulphur.
    Type: Grant
    Filed: October 28, 1975
    Date of Patent: November 30, 1976
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gunther Beck, Helmut Heitzer, Hans Holtschmidt