Patents by Inventor Tsujii Masahiko

Tsujii Masahiko 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).

  • Publication number: 20040198973
    Abstract: A process for the preparation of carbapenem antibiotics, which is free from the two disadvantages: (1) use of column chromatography and (2) recovery of a difficulty soluble salt and by which the objective compounds can be efficiently prepared in a short period. Specifically, a process for the preparation of compounds represented by the general formula (IV), salts thereof, or hydrates of both, characterized by reacting a compound represented by the general formula (I) with a compound represented by the general formula (II): X—H (wherein X is a member selected from the group consisting of substituents represented by the formulae (X-1) to (X-8)) to thereby obtain a compound represented by the general formula (III) or salt thereof, converting the compound (III) or salt thereof into a compound represented by the general formula (IV) or a salt thereof through the removal of the protecting group (R3), and purifying the compound (IV) or salt thereof by crystallization.
    Type: Application
    Filed: February 13, 2004
    Publication date: October 7, 2004
    Inventors: Tsujii Masahiko, Hiroyuki Ishizuka, Atsushi Koiwa