Patents Assigned to Masayuki Ishikawa
  • Patent number: 4451467
    Abstract: The 4(3H)-quinazolinone compounds of the formula (I) ##STR1## wherein R.sub.1 and R.sub.3, independently from each other, represent a lower alkyl group;R.sub.2 represents a lower alkoxycarbonyl group;Q represents a phenyl group or a substituted phenyl group substituted by at least one member selected from the group consisting of halogen atoms, lower alkyl groups, lower alkoxy groups, di(lower)-alkylamino groups, a methylenedioxy group, a trifluoromethyl group, a hydroxyl group, and a nitro group;R.sub.4 represents a hydrogen atom or a lower alkyl group;R.sub.
    Type: Grant
    Filed: January 6, 1982
    Date of Patent: May 29, 1984
    Assignee: Masayuki Ishikawa
    Inventors: Masayuki Ishikawa, Yukuo Eguchi, Soyao Moriguchi, Hisashi Ebisawa
  • Patent number: 4405623
    Abstract: A 5,6,7-substituted-2,4(1H,3H)-quinazolinedione compound of the formula (I), ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, A and B are as defined in claim 1 and its acid addition salt; and a vasodilating and hypotensive composition containing the aforesaid compound.
    Type: Grant
    Filed: May 15, 1981
    Date of Patent: September 20, 1983
    Assignee: Masayuki Ishikawa
    Inventors: Masayuki Ishikawa, Akiko Sugimoto, Yukuo Eguchi, Fujinori Sasaki, Hisashi Ebisawa, Soyao Moriguchi, Katsuhiko Gotoh
  • Patent number: 4293553
    Abstract: Novel 1-phthalazone derivatives of the following formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are as defined in claim 1, and pharmaceutically acceptable acid addition salts thereof; a process for production thereof; a pharmaceutical composition containing said compound; and a method for treating a thrombotic disease using said compound.
    Type: Grant
    Filed: August 7, 1979
    Date of Patent: October 6, 1981
    Assignee: Masayuki Ishikawa
    Inventors: Masayuki Ishikawa, Hiromichi Tanaka, Yukuo Eguchi, Shigeru Ito, Yoshimi Takashima, Masahiko Kobayashi
  • Patent number: 4276295
    Abstract: Novel 3-aromatic moiety substituted-4(3H)-quinazolinone derivatives useful as a vasodilators, hypotensive and antiatherosclerotic agents having the formula of ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and Q are as defined in the accompanying specification or its acid addition salt; and a process for producing the same.
    Type: Grant
    Filed: December 14, 1979
    Date of Patent: June 30, 1981
    Assignee: Masayuki Ishikawa
    Inventors: Masayuki Ishikawa, Hiromichi Tanaka, Yukuo Eguchi, Shigeru Ito, Yoshimi Takashima, Masahiko Kobayashi
  • Patent number: 4011250
    Abstract: 1.alpha.,2.alpha.-Dihydroxycholecaliciferol having improved vitamin D activities and a process for preparing the same are disclosed.
    Type: Grant
    Filed: August 6, 1975
    Date of Patent: March 8, 1977
    Assignees: Masayuki Ishikawa, Chikara Kaneko, Satoshi Sasaki, Tatsuo Suda
    Inventors: Masayuki Ishikawa, Chikara Kaneko, Satoshi Sasaki, Tatsuo Suda, Sachiko Yamada, Akiko Sugimoto