Patents by Inventor Kazuharu Tamazawa

Kazuharu Tamazawa 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).

  • Dihydropyridine-3, 5-dicarboxylic acid ester derivatives
    Patent number: 5616715
    Abstract: A process is provided for producing diastereoisomer A or a pharmaceutically acceptable acid addition salt of 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-(1-benzylpyrrolidin-3-yl) ester 5-methyl ester which comprises subjecting a mixture of diastereoisomers A and B of 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-(1-benzylpyrrolidin-3-yl) ester 5-methyl ester to column chromatography using silica gel as a carrier and a mixture of ethyl acetate and acetic acid as an eluant, and then separating the acetate of diastereoisomer A from the eluate, or treating the acetate with a base, or further treating the resulting diastereoisomer A with a pharmaceutically acceptable acid.
    Type: Grant
    Filed: June 19, 1995
    Date of Patent: April 1, 1997
    Assignee: Yamanouchi Pharmaceutical Co., Ltd.
    Inventors: Kazuharu Tamazawa, Tadao Kojima, Hideki Arima, Yukiyasu Murakami, Yasuo Isomura, Minoru Okada, Toichi Takenaka, Kiyoshi Takanobu
  • Dihydropyridine-3,5-dicarboxylic acid ester derivatives
    Patent number: 5463064
    Abstract: A dextro-rotatory optical isomer of diastereoisomer A of (.+-.)-2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-(1-benzylpyrrolidin-3-yl)ester 5-methyl ester is provided having the formula ##STR1## and wherein the melting point of the hydrochloride of the dextro-rotatory optical isomer is 223.degree. to 230.degree. C. (decomp.), or a pharmaceutically acceptable acid addition salt thereof.
    Type: Grant
    Filed: May 5, 1994
    Date of Patent: October 31, 1995
    Assignee: Yamanouchi Pharmaceutical Co., Ltd.
    Inventors: Kazuharu Tamazawa, Tadao Kojima, Hideki Arima, Yukiyasu Murakami, Yasuo Isomura, Minoru Okada, Kiyoshi Takanobu, Toichi Takenaka
  • Dihydropyridine-3,5-dicarboxylic acid ester derivatives
    Patent number: 5364872
    Abstract: The diastereoisomer A of a dihydropyridine-3,5-dicarboxylic acid ester derivative is provided as well as its pharmaceutically acceptable acid addition salts. The invention further discloses a process for producing the compounds and their use as medicaments in imparting vasodilating activity.
    Type: Grant
    Filed: January 23, 1992
    Date of Patent: November 15, 1994
    Assignee: Yamanouchi Pharmaceutical Co., Ltd.
    Inventors: Kazuharu Tamazawa, Tadao Kojima, Hideki Arima, Yukiyasu Murakami, Yasuo Isomura, Minoru Okada, Toichi Takenaka, Kiyoshi Takanobu
  • Process for producing 7.beta.-amino-7.alpha.-methoxycephalosporins
    Patent number: 4210751
    Abstract: Process for producing 7.beta.-amino-7.alpha.-methoxycephalosporins without the epimerization or formation of the corresponding 7.alpha.-amino-7.beta.-methoxy isomers by deacylating cephalosporin derivatives having 7.beta.-acylamino-7.alpha.-methoxy group.
    Type: Grant
    Filed: August 2, 1978
    Date of Patent: July 1, 1980
    Assignee: Yamanouchi Pharmaceutical Co., Ltd.
    Inventors: Kazuharu Tamazawa, Takashi Fujikura, Tadao Kojima, Masaru Iwanami
  • Process for producing 2-aminomethyl-1-ethylpyrrolidine
    Patent number: 4035252
    Abstract: A process for producing 2-aminomethyl-1-ethylpyrrolidine by the electrolytic reduction of 1-ethyl-2-nitromethylenepyrrolidine.
    Type: Grant
    Filed: August 6, 1976
    Date of Patent: July 12, 1977
    Assignee: Yamanouchi Pharmaceutical Co., Ltd.
    Inventors: Keijiro Odo, Eiichi Ichikawa, Kazuharu Tamazawa, Kozo Takahashi
  • Sodium .beta.-[2,6-dimethyl-3,5-bis(ethoxycarbonyl)-4-(3-nitrophenyl)-1,4-dihyd ropyridine-1-yl]ethyl sulfate
    Patent number: 4021434
    Abstract: Novel 1-substituted-1, 4-dihydropyridine derivatives, particularly diethyl 1-ethoxymethyl-4-(3-nitrophenyl)-2, 6-dimethyl-1, 4-dihydropyridine-3,5-dicarboxylate are provided. The novel derivatives have cerebral vascular dilator activity with low toxicity.
    Type: Grant
    Filed: August 21, 1975
    Date of Patent: May 3, 1977
    Assignee: Yamanouchi Pharmaceutical Co., Ltd.
    Inventors: Masuo Murakami, Kozo Takahashi, Teruaki Ozasa, Kazuharu Tamazawa, Ryutaro Kawai, Toichi Takenaka, Norio Sato