Patents by Inventor Ryo Kikuchi

Ryo Kikuchi 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).

  • Method for production of .beta.-lactam derivatives
    Patent number: 5070194
    Abstract: This invention provides a method of producing a .beta.-lactam derivative represented by the formula (I): ##STR1## said method consisting essentially of the step of reacting a .beta.-lactam derivative represented by the formula (II): ##STR2## with a phenol in a reaction system which consists essentially of said .beta.-lactam derivative of formula (II) and said phenol.
    Type: Grant
    Filed: April 5, 1989
    Date of Patent: December 3, 1991
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Michio Sasaoka, Nori Saito, Takashi Shiroi, Shigemitsu Nagao, Ryo Kikuchi, Yutaka Kameyama
  • Method for production of 3-exomethylenecepham derivatives
    Patent number: 4958018
    Abstract: Disclosed is a method of producing a 3-exomethylenecepham of the formula ##STR1## wherein R.sup.1 is amino or substituted amino and R.sup.2 is a carboxy-protecting group comprising reacting a cephem of the formula ##STR2## wherein R.sup.1 and R.sup.2 are as defined above and X is halogen with lead metal while maintaining the pH of the reaction system at about 0.1 to 8. The cephem (I) may be reacted with a catalytic amount of lead metal or a lead compound in the presence of a metal having a greater ionization tendency than lead.
    Type: Grant
    Filed: May 4, 1989
    Date of Patent: September 18, 1990
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Sigeru Torii, Hideo Tanaka, Masatoshi Taniguchi, Michio Sasaoka, Norio Saito, Takashi Shiroi, Shigemitsu Nagao, Ryo Kikuchi, Yutaka Kameyama