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).
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Patent number: 5700938Abstract: 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: GrantFiled: June 6, 1995Date of Patent: December 23, 1997Assignees: Eisai Co., Ltd., Eisai Chemical Co., Ltd.Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino
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Patent number: 5637716Abstract: 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: GrantFiled: December 27, 1995Date of Patent: June 10, 1997Assignees: Eisai Co., Ltd., Eisai Chemical Co., Ltd.Inventors: Yuuki Komatsu, Norio Minami, Ken Furukawa, Hiroshi Nishimura, Yoji Yamagishi
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Patent number: 5618969Abstract: 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: GrantFiled: October 19, 1995Date of Patent: April 8, 1997Assignees: Eisai Co., Ltd., Eisai ChemicalInventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino
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Patent number: 5608068Abstract: 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: GrantFiled: June 6, 1995Date of Patent: March 4, 1997Assignees: Eisai Co., Ltd., Eisai Chemical Co., Ltd.Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino
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Patent number: 5587504Abstract: 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: GrantFiled: October 19, 1995Date of Patent: December 24, 1996Assignees: Eisai Co., Ltd., Eisai Chemical Co., Ltd.Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino
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Patent number: 5583229Abstract: 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: GrantFiled: August 5, 1994Date of Patent: December 10, 1996Assignee: Eisai Co., Ltd.Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino
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Patent number: 5559236Abstract: 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: GrantFiled: June 6, 1995Date of Patent: September 24, 1996Assignees: Eisai Co., Ltd., Eisai Chemical Co., Ltd.Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino
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Patent number: 5557002Abstract: 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: GrantFiled: June 6, 1995Date of Patent: September 17, 1996Assignees: Eisai Co., Ltd., Eisai Chemical Co., Ltd.Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino
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Patent number: 5554757Abstract: 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: GrantFiled: June 6, 1995Date of Patent: September 10, 1996Assignee: Eisai Co., Ltd.Inventors: Yoshio Urawa, Ken Furukawa, Toshikazu Shimizu, Yoji Yamagishi, Tomio Tsurugi, Tomio Ichino