Patents by Inventor Toshiyuki Takezawa

Toshiyuki Takezawa 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).

  • Patent number: 5688985
    Abstract: A process for producing a (4S)-4-(N,N-dibenzyl)amino-5-phenyl-3-oxo-pentanenitrile derivative which comprises reacting a (2S)-2-(N,N-dibenzyl)aminophenylalanine ester derivative with acetonitrile in the presence of a lithium compound or a magnesium compound is disclosed, and a process for producing a (2S)-2-(N,N-dibenzyl)amino-5-amino-1,6-diphenyl-4-hexen-3-one derivative which comprises adding a benzylmagnesium halide or a benzyllithium to a reaction solution containing the (4S)-4-(N,N-dibenzyl)amino-5-phenyl-3-oxo-pentanenitrile derivative and reacting the derivative with the benzylmagnesium halide or the benzyllithium is also disclosed. According to these processes, optically pure (4S)-4-(N,N-dibenzyl)amino-5-phenyl-3-oxo-pentanenitrile derivative and (2S)-2-(N,N-dibenzyl)amino-5-amino-1,6-diphenyl-4-hexen-3-one derivative can be produced in a good yield on an industrial scale.
    Type: Grant
    Filed: January 23, 1996
    Date of Patent: November 18, 1997
    Assignee: Takasago International Corporation
    Inventors: Mitsuhiko Fujihara, Kenji Asahina, Toru Watanabe, Toshiyuki Takezawa, Seiji Watanabe
  • Patent number: 4962242
    Abstract: A process for producing an optically active alcohol represented by formula (I): ##STR1## wherein R.sub.1 is an alkyl group having from 2 to 11 carbon atoms, an alkenyl group having from 3 to 11 carbon atoms, an alkadienyl group having from 6 to 11 carbon atoms, a cyclohexyl group, an cyclohexylmethyl group, or a cyclohexylethyl group, provided that the olefin in the alkenyl group or alkadienyl group is not conjugated to the olefin at the 2-position thereof; and * means an asymmetric carbon atom,is disclosed, comprising subjecting an olefinic alcohol represented by formula (II): ##STR2## wherein R.sub.1 is the same as defined above to asymmetric hydrogenation in the presence of, as a catalyst, a ruthenium-optically active phosphine complex.According to the process of the invention, the desired optically active alcohols which are useful not only as intermediates for the manufacture of perfumes and vitamin E but also as liquid crystal materials can be produced with high optical purities.
    Type: Grant
    Filed: June 25, 1987
    Date of Patent: October 9, 1990
    Assignee: Takasago Perfumery Co., Ltd.
    Inventors: Nobuo Yamada, Toshiyuki Takezawa, Noboru Sayo, Misao Yagi, Hidenori Kumobayashi, Susumu Akutagawa, Hidemasa Takaya, Shinichi Inoue, Ryoji Noyori
  • Patent number: 4739084
    Abstract: A ruthenium-phosphine complex having a 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl or its derivative as a ligand and carboxyl groups bonded to the ruthenium atom thereof is disclosed. The complex is inexpensive and exhibits excellent performances as a catalyst for various organic syntheses, and particularly for asymmetric hydrogenation.
    Type: Grant
    Filed: April 15, 1987
    Date of Patent: April 19, 1988
    Assignee: Takasago Perfumery Co., Ltd.
    Inventors: Hidemasa Takaya, Tetsuo Ohta, Ryoji Noyori, Nobuo Yamada, Toshiyuki Takezawa, Noboru Sayo, Takanao Taketomi, Hidenori Kumobayashi, Susumu Akutagawa
  • Patent number: 4410724
    Abstract: There is provided a process for production of o-(2,6-dichloroanilino)phenylacetic acid or a salt thereof by reacting o-chlorophenylacetic acid or an alkali metal salt thereof with 2,6-dichloroaniline in the presence of a base and at least 0.5 mol of a copper catalyst per mol of o-chlorophenylacetic acid in a polar solvent.
    Type: Grant
    Filed: October 16, 1981
    Date of Patent: October 18, 1983
    Assignee: Zenyaku Kogyo Kabushiki Kaisha
    Inventors: Muneaki Takase, Tadahiro Nakamura, Kazuo Kamiya, Toshiyuki Takezawa, Hiroaki Yamazaki, Takashi Iwaki