Patents by Inventor Chihiro Nakanishi

Chihiro Nakanishi 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).

  • Cis-oxalato(trans-1-1,2-cyclohexanediamine) Pt(II) complex having high optical purity and process of preparing same
    Patent number: 5420319
    Abstract: Disclosed is cis-oxalato(trans-1-1,2-cyclohexanediamine) Pt(II) complex having high optical purity and no toxicity and exhibiting anticancer performance, as shown in the below Formula.Cis-oxalato(trans-1-1,2-cyclohexanediamine) Pt(II) complex of the invention possesses high optical purity or 99.94% or more e.e. and a melting point of 198.3.degree. to 199.7.degree. C. The complex is synthesized employing as starting material trans-1-1,2-cyclohexamediamine or a derivative of the trans-1-1,2-cyclohexanediamine optically resoluted by means of a high performance liquid chromatography.
    Type: Grant
    Filed: September 7, 1993
    Date of Patent: May 30, 1995
    Assignee: Tanaka Kikinzoku Kogyo K.K.
    Inventors: Koji Okamoto, Chihiro Nakanishi, Junichi Taniuchi, Junji Ohnishi, Yasunobu Komoda
  • Cis oxalato (trans 1-1,2-cyclohexanediamine) PT(II) having optically high purity
    Patent number: 5338874
    Abstract: Disclosed herein is cis-oxalato (trans-1-1,2-cyclohexanediamine) Pt(II) optically high purity. Because of its complete optical purity, the compound is effective as raw material of such a medicine as a carcinostatic agent. The complete optical purity of the above compound may be proved by comparing the respective melting points of the cis-oxalato (trans-1-1,2-cyclohexanediamine).
    Type: Grant
    Filed: April 7, 1993
    Date of Patent: August 16, 1994
    Assignee: Tanaka Kikinzoku Kogyo K.K.
    Inventors: Chihiro Nakanishi, Yuko Ohnishi, Junji Ohnishi, Junichi Taniuchi, Koji Okamoto, Takeshi Tozawa
  • Process of optically resoluting optically active platinum complex compound
    Patent number: 5298642
    Abstract: Disclosed herein is a process of optically resoluting optically active platinum complex compounds which comprises optically resoluting a d-isomer and an 1-isomer of a cis-Pt(II) complex of a 1,2-cyclohexanediamine isomer characterized in that the mixture of the d-isomer and the 1-isomer is optically resoluted by means of high performance liquid chromatography employing a column packed with a chiral filler.The chiral filler include, for example, a cellulose ester derivative, a cellulose carbamate derivative, an amylose carbamate derivative, a polymethacryl acid ester and .beta.- and .gamma.-cyclodextrin.According to the present invention, the optical resolution of a platinum complex compound essentially consisting of the mixture of two optical isomers which cannot be resoluted in accordance with a normal resolution method due to the small structural difference can be easily performed utilizing the characteristics of a chiral filler.
    Type: Grant
    Filed: April 7, 1993
    Date of Patent: March 29, 1994
    Assignee: Tanaka Kikinzoku Kogyo K.K.
    Inventors: Takeshi Tozawa, Yasunobu Komoda, Junji Ohnishi, Yukie Masuda, Junichi Taniuchi, Chihiro Nakanishi, Koji Okamoto
  • Platinum compound and process of preparing same
    Patent number: 5290961
    Abstract: Disclosed herein are a platinum compound employed as raw material of medicines having carcinostatic effects, and a process of preparing the platinum compound. The platinum compound (I) substantially free from impurities can be prepared through a reaction between the corresponding dihalogen compound and an organic dibasic acid employing an iodine compound utilizing the difference of solubilities between the desired compound and the iodine compounds.
    Type: Grant
    Filed: January 12, 1993
    Date of Patent: March 1, 1994
    Assignee: Tanaka Kikinzoku Kogyo K.K.
    Inventors: Koji Okamoto, Yuko Hoshi, Chihiro Nakanishi