Patents by Inventor Takashi Shiroi

Takashi Shiroi 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: 20020099206
    Abstract: The object of the invention is to provide cephalosporin crystals which are highly stable for a long period under economical storage conditions. The cephalosporin crystals of the invention are obtainable by crystallizing an oily cephalosporin in a solvent containing an alcohol.
    Type: Application
    Filed: January 9, 2002
    Publication date: July 25, 2002
    Inventors: Yutaka Kameyama, Takashi Shiroi
  • Patent number: 5770729
    Abstract: The present invention provides an ozonide reducing agent for use in the ozonolysis reaction of an organic compound, the ozonide reducing agent finding wide applications, and being safe and inexpensive from a commercial viewpoint and easy to treat for disposal.The ozonide reducing agent of the invention is a compound wherein sulfur has, at both ends of its molecule, a hydrocarbon residue substituted by a polar functional group.
    Type: Grant
    Filed: January 22, 1996
    Date of Patent: June 23, 1998
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Michio Sasaoka, Daisuke Suzuki, Takashi Shiroi
  • Patent number: 5693792
    Abstract: The object of the invention is to provide a .beta.-lactam compound and a 2-substituted methyl-3-cephem compound, both of which are of value as intermediates for the synthesis of cephem antibiotics.The .beta.-lactam compound of the invention may be represented by the general formula ##STR1## wherein R.sup.1 represents a protected amino group, for instance; R.sup.2 represents hydrogen, for instance; R.sup.3 represents hydrogen or a carboxy-protecting group; R.sup.4 represents an aryl group which may be substituted; R.sup.5 represents an alkenyl group which may be substituted, for instance. The 2-substituted methyl-3-cephem compound of the invention may be represented by the general formula ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above; R.sup.6 represents an aryl group which may be substituted.
    Type: Grant
    Filed: August 15, 1995
    Date of Patent: December 2, 1997
    Assignee: Otsuga Kagaku Kabushiki Kaisha
    Inventors: Shigeru Torii, Hideo Tanaka, Mitio Sasaoka, Takashi Shiroi, Yutaka Kameyama
  • Patent number: 5656754
    Abstract: The present invention provides a process for preparing a cephem compound represented by the general formula (3) characterized in that an allenyl-.beta.-lactam compound represented by the general formula (1) is reacted with an organotin compound represented by the general formula (2) in the presence of a monovalent copper salt ##STR1## wherein R.sup.1 is a hydrogen atom, halogen atom, amino or protected amino, R.sup.2 is a hydrogen atom, halogen atom, lower alkoxyl, lower acyl, lower alkyl, lower alkyl having hydroxyl or protected hydroxyl as a substituent, hydroxyl or protected hydroxyl, or R.sup.1 and R.sup.2 form=0 when taken together, R.sup.3 is a hydrogen atom or carboxylic acid protecting group, R.sup.4 is aryl, aryl having a substituent, nitrogen-containing aromatic heterocyclic group or nitrogen-containing aromatic heterocyclic group having a substituent, and m is 0 or 2,(R.sup.5).sub.n --Sn(R.sup.6).sub.4--n (2)wherein R.sup.
    Type: Grant
    Filed: March 22, 1994
    Date of Patent: August 12, 1997
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Shigeru Torii, Hideo Tanaka, Michio Sasaoka, Takashi Shiroi, Yutaka Kameyama
  • Patent number: 5656755
    Abstract: An object of the invention is to provide a process for preparing a 3-substituted cephem compound from an allenyl-.beta.-lactam compound which can be easily produced from an inexpensive penicillin compound by a simple reaction procedure.The process of the invention comprises reacting an allenyl-.beta.-lactam compound with an organohalogen compound in the presence of a metal having a standard oxidation-reduction potential of -0.3 (V/SCE) or less in an amount at least equimolar with the allenyl-.beta.-lactam compound and 0.0001 to 0.5 mole, per mole of the allenyl-.beta.-lactam compound, of a metal compound having a higher standard oxidation-reduction potential than said metal.
    Type: Grant
    Filed: July 6, 1995
    Date of Patent: August 12, 1997
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Shigeru Torii, Hideo Tanaka, Michio Sasaoka, Takashi Shiroi
  • Patent number: 5599925
    Abstract: A penam derivative of the general formula ##STR1## wherein R.sup.1 means hydrogen, halogen, amino or protected amino; R.sup.2 means hydrogen, halogen, lower alkoxy, lower acyl, lower alkyl, hydroxy- or protected hydroxy-substituted lower alkyl, hydroxy or protected hydroxy, or R.sup.1 and R.sup.2 may jointly represent oxo; R.sup.3 means hydrogen or a carboxy-protecting group; R.sup.4 means hydrogen; R.sup.5 means a group of the formula --CH.sub.2 Y where Y means halogen, --N.sub.3, --ONO.sub.2, --OR.sup.6, --OCOR.sup.6, --SCSOR.sup.6, --SCSN(R.sup.6).sub.2, --SR.sup.6, --SO.sub.2 R.sup.6, --NHR.sup.6, --N(R.sup.6).sub.2 or a substituted or unsubstituted nitrogen-containing heterocyclic group having a free valence on nitrogen; R.sup.6 means a lower alkyl, aryl or heterocyclic group which is substituted or unsubstituted; or R.sup.4 and R.sup.5 may jointly represent .dbd.CH.sub.2 ; n means 0, 1 or 2; provided, however, that where R.sup.4 and R.sup.5 jointly represent .dbd.CH.sub.2, n is not equal to 0.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: February 4, 1997
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Shigeru Torii, Hideo Tanaka, Masatoshi Taniguchi, Mitio Sasaoka, Takashi Shiroi, Yutaka Kameyama
  • Patent number: 5470972
    Abstract: The object of the invention is to provide a .beta.-lactam compound and a 2-substituted methyl-3-cephem compound, both of which are of value as intermediates for the synthesis of cephem antibiotics.The .beta.-lactam compound of the invention may be represented by the general formula ##STR1## wherein R.sup.1 represents a protected amino group, for instance; R.sup.2 represents hydrogen for instance; R.sup.3 represents hydrogen or a carboxy-protecting group; R.sup.4 represents an aryl group which may be substituted; R.sup.5 represents an alkenyl group which may be substituted, for instance. The 2-substituted methyl-3-cephem compound of the invention may be represented by the general formula ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above; R.sup.6 represents an aryl group which may be substituted.
    Type: Grant
    Filed: October 14, 1993
    Date of Patent: November 28, 1995
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Shigeru Torii, Hideo Tanaka, Mitio Sasaoka, Takashi Shiroi, Yutaka Kameyama
  • Patent number: 5288860
    Abstract: The present invention provides a thiazolinoazetidinone derivative represented by the formula ##STR1## wherein R.sup.1 is phenyl having or not having substituent(s), methyl having or not having substituent(s) or ##STR2## group, R.sup.3 being phenyl having or not having substituent(s), and R.sup.2 is a hydrogen atom or carboxylic acid protective group, and a process for preparing the same.The present invention further provides a process for preparing a 2-exo-methylenepenam derivative characterized by hydrolyzing the thiazoline ring of a thiazolinoazetidinone derivative of the above formula (1) to effect recyclization and obtain a 2-exo-methylenepenam derivative represented by the formula ##STR3## wherein R.sup.1 and R.sup.2 are as defined above.
    Type: Grant
    Filed: January 11, 1993
    Date of Patent: February 22, 1994
    Assignee: Otsuka Kagaku Kasbushiki Kaisha
    Inventors: Sigeru Torii, Hideo Tanaka, Masatoshi Taniguchi, Michio Sasaoka, Takashi Shiroi, Yutaka Kameyama
  • Patent number: 5206361
    Abstract: The present invention provides a thiazolinoazetidinone derivative represented by the formula ##STR1## wherein R.sup.1 is phenyl having or not having substituent(s), methyl having or not having substituent(s) or ##STR2## group, R.sup.3 being phenyl having or not having substituent(s), and R.sup.2 is a hydrogen atom or carboxylic acid protective group, and a process for preparing the same.The present invention further provides a process for preparing a 2-exo-methylenepenam derivative characterized by hydrolyzing the thiazoline ring of a thiazolinoazetidinone derivative of the above formula (1) to effect recyclization and obtain a 2-exo-methylenepenam derivative represented by the formula ##STR3## wherein R.sup.1 and R.sup.2 are as defined above.
    Type: Grant
    Filed: March 7, 1991
    Date of Patent: April 27, 1993
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Sigeru Torii, Hideo Tanaka, Masatoshi Taniguchi, Michio Sasaoka, Takashi Shiroi, Yutaka Kameyama
  • Patent number: 5204458
    Abstract: The present invention provides a process for preparing a cephem derivative characterized in that an allenyl .beta.-lactam compound represented by the formula (1) ##STR1## wherein R.sup.1 is amino or protected amino, R.sup.2 is a hydrogen atom or lower alkoxyl, R.sup.3 is a hydrogen atom or carboxylic acid protecting group and X is the group --SO.sub.2 R.sup.4 or --SR.sup.4, R.sup.4 being substituted or unsubstituted aryl or substituted or unsubstituted nitrogen-containing aromatic heterocyclic group is reacted with a nucleophilic agent to obtain the derivative, the cephem derivative being represented by the formula (2) ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above, and Y is the residue of the nucleophilic agent.
    Type: Grant
    Filed: March 10, 1992
    Date of Patent: April 20, 1993
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Sigeru Torii, Hideo Tanaka, Masatoshi Taniguchi, Michio Sasaoka, Takashi Shiroi, Yutaka Kameyama
  • Patent number: 5196530
    Abstract: The present invention provides a process for preparing a 2-exo-methylenepenam derivative represented by the formula (2), the process being characterized by reacting an allenyl .beta.-lactum compound represented by the formula (1) with a metallic reducing agent, in which R.sup.1, R.sup.2, R.sup.3 and X are defined in the specification.
    Type: Grant
    Filed: March 10, 1992
    Date of Patent: March 23, 1993
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Sigeru Torii, Hideo Tanaka, Masatoshi Taniguchi, Michio Sasaoka, Takashi Shiroi, Yutaka Kameyama
  • Patent number: 5142040
    Abstract: The present invention provides a process for preparing a 3-formylcephem derivative represented by the formula (2) ##STR1## which comprises oxidizing in the presence of oxygen a 3-halomethylcephem derivative represented by the formula (1) ##STR2## wherein R.sup.1 is amino group or protected amino group, R.sup.2 is hydrogen atom or a carboxylic acid protective group, X is halogen atom.
    Type: Grant
    Filed: March 7, 1991
    Date of Patent: August 25, 1992
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Sigeru Torii, Hideo Tanaka, Masatoshi Taniguchi, Michio Sasaoka, Takashi Shiroi, Ryo Kikuchi, Yutaka Kameyama
  • Patent number: 5126447
    Abstract: A process for preparing a .beta.-lactam derivative of formula (2) and/or the corresponding enol tautomer, which includes oxidizing an alkenyl-substituted .beta.-lactam derivative of formula (1) in the presence of a ruthenium catalyst or a rhenium catalyst using a periodic acid: ##STR1## wherein R.sup.1 is a hydrogen atom, a C.sub.1-4 alkyl group or a C.sub.1-4 haloalkyl group, R.sup.2 is a hydrogen atom, a C.sub.1-4 alkyl group or a phenyl group which may have a substituent, A is a group selected from ##STR2## wherein R.sup.3 is an amino group or a protected amino group, and R.sup.4 -R.sup.8 are as defined in the application.
    Type: Grant
    Filed: March 1, 1991
    Date of Patent: June 30, 1992
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Sigeru Torii, Hideo Tanaka, Masatoshi Taniguchi, Michio Sasaoka, Takashi Shiroi, Ryo Kikuchi, Yutaka Kameyama
  • 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
  • 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
  • Patent number: 4853468
    Abstract: This invention provides azetidinone derivatives represented by the formula ##STR1## and processes for preparing the same. The azetidinone derivatives are used as the intermediates for producing cephalosporin compounds useful as antibiotic agents.
    Type: Grant
    Filed: March 11, 1988
    Date of Patent: August 1, 1989
    Assignee: Otsuka Kagaku Yakuhin Kabushiki Kaisha
    Inventors: Sigeru Torii, Kenji Uneyama, Hideo Tanaka, Junzo Nokami, Michio Sasaoka, Norio Saito, Takashi Shiroi
  • Patent number: 4798890
    Abstract: A process for preparing an azetidinone derivative represented by the formula ##STR1## wherein R.sup.1 is hydrogen, halogen or lower alkoxy, R.sup.2 is hydrogen, halogen, lower alkoxy, amino or a group ##STR2## (in which R.sup.5 is substituted or unsubstituted phenyl, substituted or unsubstituted phenylmethyl, substituted or unsubstituted phenoxymethyl, or substituted or unsubstituted benzoyl), or R.sup.1 and R.sup.2, when taken together, are carbonyl, R.sup.3 is substituted or unsubstituted phenyl, and R.sup.4 is hydrogen, optionally substituted hydrocarbon residue or acyl, silyl, sulfonyl or phosphonyl derived from inorganic acid or organic acid, the process comprising reacting a dithioazetidinone derivative represented by the formula ##STR3## wherein R.sup.1, R.sup.2 and R.sup.4 are as defined above and R.sup.9 is substituted or unsubstituted, nitrogen-containing aromatic heterocyclic residue with a compound represented by the formulaR.sup.3 SO.sub.2 H (VII)wherein R.sup.3 is defined above.
    Type: Grant
    Filed: April 21, 1988
    Date of Patent: January 17, 1989
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Sigeru Torii, Hideo Tanaka, Michio Sasaoka, Takashi Shiroi
  • Patent number: 4784734
    Abstract: This invention provides azetidinone derivatives represented by the formula ##STR1## and processes for preparing the same. The azetidinone derivatives are used as the intermediates for producing cephalosporin compounds useful as antibiotic agents.
    Type: Grant
    Filed: July 9, 1987
    Date of Patent: November 15, 1988
    Assignee: Otsuka Kagaku Yakuhin Kabushiki Kaisha
    Inventors: Sigeru Torii, Kenji Uneyama, Hideo Tanaka, Junzo Nokami, Michio Sasaoka, Norio Saito, Takashi Shiroi
  • Patent number: 4689411
    Abstract: This invention provides azetidinone derivatives represented by the formula ##STR1## and processes for preparing the same. The azetidinone derivatives are used as the intermediates for producing cephalosporin compounds useful as antibiotic agents.
    Type: Grant
    Filed: May 15, 1986
    Date of Patent: August 25, 1987
    Assignee: Otsuka Kagaku Yakuhin Kabushiki Kaisha
    Inventors: Sigeru Torii, Kenji Uneyama, Hideo Tanaka, Junzo Nokami, Michio Sasaoka, Norio Saito, Takashi Shiroi
  • Patent number: 4665166
    Abstract: A process for preparing cephalosporin compounds represented by the formula ##STR1## wherein R.sup.1 represents an alkyl group, alkenyl group, substituted or unsubstituted aryl group, substituted or unsubstituted arylmethyl group or substituted or unsubstituted phenoxymethyl group, R.sup.2 represents a carboxyl group or protected carboxyl group, and Y represents the residue of a nucleophilic reagent.
    Type: Grant
    Filed: May 1, 1984
    Date of Patent: May 12, 1987
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Shigeru Torii, Hideo Tanaka, Junzo Nogami, Michio Sasaoka, Norio Saito, Takashi Shiroi