Patents by Inventor Yoshitake Naoi

Yoshitake Naoi 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).

  • Method for preparing 2'-3'-dideoxy-.beta.-nucleosides using 2,2-dideoxy-di(organothio)-pentofuranose intermediates
    Patent number: 5416204
    Abstract: 2,3-Dideoxy-2,2-di(organothio)-B-D-pentofuranosyl-pyrimidines are disclosed as intermediates in the synthesis of 2', 3'-dideoxynucleosides and have the structure shown below. ##STR1## wherein R.sup.4 is a hydroxyl protecting group;X is oxygen or nitrogen, said nitrogen being bonded to a hydrogen atom, an alkyl or acyl group;Y is hydrogen, halogen, alkyl, haloalkyl or haloalkenyl; andR.sup.5 is alkyl, aralkyl, or aryl wherein aralkkyl or aryl is substituted with hydrogen, halogen, nitro or alkoxy.2', 3'-Dideoxynucleosides, products of the above intermediates, are useful as antiviral agents.
    Type: Grant
    Filed: February 12, 1993
    Date of Patent: May 16, 1995
    Assignee: Japan Tobacco, Incorporated
    Inventors: Hiroshi Kawakami, Katsuya Matsumoto, Koshi Koseki, Takashi Ebata, Hajime Matsushita, Kazuo Itoh, Yoshitake Naoi
  • Process for preparing 2'-deoxy-.beta.-adenosine
    Patent number: 5262531
    Abstract: 2'-deoxy-.beta.-adenosine can be industrially and easily obtained without using expensive or dangerous materials by the process of the present invention, which comprises the steps of: preparing a salt of adenine from adenine, allowing to condense the salt with a derivative of pentofuranose to isolate a derivative of adenine, and then eliminating the protecting groups.
    Type: Grant
    Filed: June 30, 1989
    Date of Patent: November 16, 1993
    Assignees: Japan Tobacco, Inc., Yuki Gosei Kogyo, Co. Ltd.
    Inventors: Hiroshi Kawakami, Hajime Matsushita, Hajima Yoshikoshi, Kazuo Itoh, Yoshitake Naoi
  • Method of producing (S)-4-hydroxymethyl-.gamma.-lactone
    Patent number: 5112994
    Abstract: (S)-4-hydroxymethyl-.gamma.-lactone is prepared by oxidizing dihydrolevoglucosenone with a peracid in an organic solvent. (S)-4-hydroxymethyl-.gamma.-lactone is prepared from levoglucosenone. First, levoglucosenone is catalytic hydrogenated, thereby dihydrolevoglucosenone is obtained. Next, dihydrolevoglucosenone thus obtained is oxidized with a peracid in an organic solvent, thereby (S)-4-hydroxymethyl-.gamma.-lactone is obtained. In this manner, (S)-4-hydroxymethyl-.gamma.-lactone can be obtained with high optical purity.
    Type: Grant
    Filed: September 17, 1990
    Date of Patent: May 12, 1992
    Assignees: Japan Tobacco Inc., Yuki Gosei Kogyo Co., Ltd.
    Inventors: Koshi Koseki, Takashi Ebata, Hiroshi Kawakami, Hajime Matsushita, Kazuo Itoh, Yoshitake Naoi
  • Process for preparing 2'-deoxy-5-trifluoromethyl-beta-uridine
    Patent number: 5006646
    Abstract: The present invention is a process for preparing 2'-deoxy-5-trifluoromethyl-.beta.uridine characterized in that a 5-trifluoromethyl-2,4-bis(triorganosilyloxy)pyrimidine and a 1-halogeno-2-deoxy-.alpha.-D-erythro-pentofuranose derivative are subjected to condensation reaction in chloroform to give a 1-(2-deoxy-.beta.-D-erythro-pentofuranoxyl)-5-trifluoromethyluracil derivative which is then subjected to the deprotection reaction to give 2'-deoxy-5-trifluoromethyl-.beta.-uridine.
    Type: Grant
    Filed: February 20, 1990
    Date of Patent: April 9, 1991
    Assignees: Yuki Gosei Kogyo Co., Ltd., Japan Tobacco Co.
    Inventors: Kazuo Itoh, Yoshitake Naoi, Hajime Matsushita, Takashi Ebata, Hiroshi Kawakami
  • Method of preparing (S)-.gamma.-hydroxymethyl-.alpha., .beta.-butenolide
    Patent number: 4994585
    Abstract: A method of preparing (S)-.gamma.-hydroxymethyl-.alpha.,.beta.-butenolide includes the step of oxidizing a levoglucosenone with a peracid in an organic solvent. Peracetic acid, metha-chloroperbenzoic acid or magnesium monoperoxyphthalate hexahydrate can be used as the peracid. According to this method, an (S)-.gamma.-hydroxymethyl-.alpha.,.beta.-butenolide having high optical purity can be easily prepared from a levoglucosenone as a starting material at a high yield.
    Type: Grant
    Filed: July 10, 1990
    Date of Patent: February 19, 1991
    Assignees: Japan Tabacco Inc., Yuki Gosei Kogyo Co., Ltd.
    Inventors: Koshi Koseki, Takashi Ebata, Hiroshi Kawakami, Hajime Matsushita, Kazuo Itoh, Yoshitake Naoi