Patents by Inventor Yoji Yamagishi

Yoji Yamagishi 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: 5700938
    Abstract: The present invention provides an industrially advantageous process for preparing a 2-alkyl-3-(biphenyl-4-yl)methyl-3H-imidazo?4,5-b!pyridine derivative represented by the following formula (II) which is a precursor of an antagonist against an angiotensin II receptor useful as an antihypertensive drug, a biphenyl derivative which is a precursor of the substituent of the pyridine derivative, a process for the preparation thereof, and an intermediate useful for the preparation of the biphenyl derivative: ##STR1## The 2-alkyl-3-(biphenyl-4-yl)methyl-3H-imidazo?4,5-b!pyridine derivative can be prepared in a high yield according to the present invention from a 2-amino-5-halogeno-3-nitropyridine derivative through amidation, N-alkylation and reductive cyclization. The halogen atom introduced at the 5-position as a protective group against nitration can be eliminated simultaneously in the step which is conducted thereafter. Thus, this process is industrially advantageous.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: December 23, 1997
    Assignees: Eisai Co., Ltd., Eisai Chemical Co., Ltd.
    Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino
  • Patent number: 5637716
    Abstract: Intermediates for the preparation of benzothiazole derivatives useful for the prevention and treatment of diseases for which an inhibitory action against the production of leukotriene and thromboxane is efficacious, and industrially advantageous processes for the preparation of the intermediates.
    Type: Grant
    Filed: December 27, 1995
    Date of Patent: June 10, 1997
    Assignees: Eisai Co., Ltd., Eisai Chemical Co., Ltd.
    Inventors: Yuuki Komatsu, Norio Minami, Ken Furukawa, Hiroshi Nishimura, Yoji Yamagishi
  • Patent number: 5618969
    Abstract: The present invention provides an industrially advantageous process for preparing a 2-alkyl-3-(biphenyl-4-yl)methyl-3H-imidazo[4,5-b]pyridine derivative represented by the following formula (II) which is a precursor of an antagonist against an angiotensin II receptor useful as an antihypertensive drug, a biphenyl derivative which is a precursor of the substituent of the pyridine derivative, a process for the preparation thereof, and an intermediate useful for the preparation of the biphenyl derivative: ##STR1##
    Type: Grant
    Filed: October 19, 1995
    Date of Patent: April 8, 1997
    Assignees: Eisai Co., Ltd., Eisai Chemical
    Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino
  • Patent number: 5608068
    Abstract: The present invention provides an industrially advantageous process for preparing a 2-alkyl-3-(biphenyl-4-yl)methyl-3H-imidazo[4,5-b]pyridine derivative represented by the following formula (II) which is a precursor of an antagonist against an angiotensin II receptor useful as an antihypertensive drug, a biphenyl derivative which is a precursor of the substituent of the pyridine derivative, a process for the preparation thereof, and an intermediate useful for the preparation of the biphenyl derivative: ##STR1## The 2-alkyl-3-(biphenyl-4-yl)methyl-3H-imidazo-[4,5-b]pyridine derivative can be prepared in a high yield according to the present invention from a 2-amino-5-halogeno-3-nitropyridine derivative through amidation, N-alkylation and reductive cyclization. The halogen atom introduced at the 5-position as a protective group against nitration can be eliminated simultaneously in the step which is conducted thereafter. Thus, this process is industrially advantageous.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: March 4, 1997
    Assignees: Eisai Co., Ltd., Eisai Chemical Co., Ltd.
    Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino
  • Patent number: 5587504
    Abstract: The present invention provides an industrially advantageous process for preparing a 2-alkyl-3-(biphenyl-4-yl)methyl-3H-imidazo[4,5-b]pyridine derivative represented by the following formula (II) which is a precursor of an antagonist against an angiotensin II receptor useful as an antihypertensive drug, a biphenyl derivative which is a precursor of the substituent of the pyridine derivative, a process for the preparation thereof, and an intermediate useful for the preparation of the biphenyl derivative: ##STR1## The 2-alkyl-3-(biphenyl-4-yl)methyl-3H-imidazo[4,5-b]pyridine derivative can be prepared in a high yield according to the present invention from a 2-amino-5-halogeno-3-nitropyridine derivative through amidation, N-alkylation and reductive cyclization.
    Type: Grant
    Filed: October 19, 1995
    Date of Patent: December 24, 1996
    Assignees: Eisai Co., Ltd., Eisai Chemical Co., Ltd.
    Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino
  • Patent number: 5583229
    Abstract: The present invention provides an industrially advantageous process for preparing a 2-alkyl-3-(biphenyl-4-yl)methyl-3H-imidazo[4,5-b]pyridine derivative represented by the following formula (II) which is a precursor of an antagonist against an angiotensin II receptor useful as an antihypertensive drug, a biphenyl derivative which is a precursor of the substituent of the pyridine derivative, a process for the preparation thereof, and an intermediate useful for the preparation of the biphenyl derivative: ##STR1##
    Type: Grant
    Filed: August 5, 1994
    Date of Patent: December 10, 1996
    Assignee: Eisai Co., Ltd.
    Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino
  • Patent number: 5559236
    Abstract: The present invention provides an industrially advantageous process for preparing a 2-alkyl-3-(biphenyl-4-yl)methyl-3H-imidazo[4,5-b]pyridine derivative represented by the following formula (II) which is a precursor of an antagonist against an angiotensin II receptor useful as an antihypertensive drug, a biphenyl derivative which is a precursor of the substituent of the pyridine derivative, a process for the preparation thereof, and an intermediate useful for the preparation of the biphenyl derivative: ##STR1## The 2-alkyl-3-(biphenyl-4-yl)methyl-3H-imidazo-[4,5-b]pyridine derivative can be prepared in a high yield according to the present invention from a 2-amino-5-halogeno-3-nitropyridine derivative through amidation, N-alkylation and reductive cyclization. The halogen atom introduced at the 5-position as a protective group against nitration can be eliminated simultaneously in the step which is conducted thereafter. Thus, this process is industrially advantageous.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: September 24, 1996
    Assignees: Eisai Co., Ltd., Eisai Chemical Co., Ltd.
    Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino
  • Patent number: 5557002
    Abstract: The present invention provides an industrially advantageous process for preparing a 2-alkyl-3-(biphenyl-4-yl)methyl-3H-imidazo[4,5-b]pyridine derivative represented by the following formula (II) which is a precursor of an antagonist against an angiotensin II receptor useful as an antihypertensive drug, a biphenyl derivative which is a precursor of the substituent of the pyridine derivative, a process for the preparation thereof, and an intermediate useful for the preparation of the biphenyl derivative: ##STR1## The 2-alkyl-3-(biphenyl-4-yl)methyl-3H-imidazo[4,5-b]pyridine derivative can be prepared in a high yield according to the present invention from a 2-amino-5-halogeno-3-nitropyridine derivative through amidation, N-alkylation and reductive cyclization. The halogen atom introduced at the 5-position as a protective group against nitration can be eliminated simultaneously in the step which is conducted thereafter. Thus, this process is industrially advantageous.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: September 17, 1996
    Assignees: Eisai Co., Ltd., Eisai Chemical Co., Ltd.
    Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino
  • Patent number: 5554757
    Abstract: The present invention provides an industrially advantageous process for preparing a 2-alkyl-3-(biphenyl-4-yl)methyl-3H-imidazo[4,5-b]pyridine derivative represented by the following formula (II) which is a precursor of an antagonist against an angiotensin II receptor useful as an antihypertensive drug, a biphenyl derivative which is a precursor of the substituent of the pyridine derivative, a process for the preparation thereof, and an intermediate useful for the preparation of the biphenyl derivative: ##STR1## The 2-alkyl-3-(biphenyl-4-yl)methyl-3H-imidazo-[4,5-b]pyridine derivative can be prepared in a high yield according to the present invention from a 2-amino-5-halogeno-3-nitropyridine derivative through amidation, N-alkylation and reductive cyclization. The halogen atom introduced at the 5-position as a protective group against nitration can be eliminated simultaneously in the step which is conducted thereafter. Thus, this process is industrially advantageous.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: September 10, 1996
    Assignee: Eisai Co., Ltd.
    Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino