Patents by Inventor Franz-Josef Mais

Franz-Josef Mais 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 benzothiazepinone derivatives
    Patent number: 4948886
    Abstract: Benzothiazepinone derivatives can be prepared by alkaline hydrolysis of benzothiazoles to give o-amino-thiophenols, isolation thereof by acidification and further reaction with acrylic acids. In this connection, the acidification is carried out using a mineral acid, after which the o-amino-thiophenol is extracted using a water-insoluble solvent and is reacted in this extract with an acrylic acid.
    Type: Grant
    Filed: January 4, 1989
    Date of Patent: August 14, 1990
    Assignee: Bayer Aktiengesellschaft
    Inventors: Franz-Josef Mais, Helmut Fiege
  • Process for the ring chlorination of aromatic hydrocarbons
    Patent number: 4925994
    Abstract: Aromatic hydrocarbons which are monosubstituted by straight-chain or branched C.sub.1 -C.sub.12 -alkyl or by C.sub.3 -C.sub.8 -cycloalkyl can be chlorinated in the presence of Friedel-Crafts Catalysts in liquid phase on the aromatic ring if 1,6-benzothiazocins are used as co-catalysts. This makes it possible to obtain a higher proportion of p-isomers.
    Type: Grant
    Filed: April 24, 1989
    Date of Patent: May 15, 1990
    Assignee: Bayer Aktiengesellschaft
    Inventors: Franz-Josef Mais, Helmut Fiege
  • Process for nucleus-chlorination of aromatic hydrocarbons
    Patent number: 4851596
    Abstract: Aromatic hydrocarbons are chlorinated in the nucleus in the presence of Friedel-Crafts catalysts and in the presence of co-catalysts in the liquid phase by using thiazepines as co-catalysts.
    Type: Grant
    Filed: May 11, 1988
    Date of Patent: July 25, 1989
    Assignee: Bayer Aktiengesellschaft
    Inventors: Franz-Josef Mais, Helmut Fiege, Kai Rohlk, Karlfried Wedemeyer
  • Process for the removal of m-chlorotoluene from chlorotoluene mixtures
    Patent number: 4827058
    Abstract: m-Chlorotoluene is removed from chlorotoluene mixtures with a content of up to 10% by weight of m-chlorotoluene, with reference to the total amount of chlorotoluene in the mixture, by chlorinating a substantially toluene-free chlorotoluene mixture in the presence of a Friedel-Crafts catalyst and if appropriate a co-catalyst at from 0.degree. C. up to the boiling point of the mixture, until the content of m-chlorotoluene has decreased to a value of <1.0% by weight in the chlorotoluene mixture.
    Type: Grant
    Filed: March 10, 1988
    Date of Patent: May 2, 1989
    Assignee: Bayer Aktiengesellschaft
    Inventors: Franz-Josef Mais, Helmut Fiege