Patents by Inventor Hiroshi Shiragami
Hiroshi Shiragami 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: 12228830Abstract: According to one embodiment, a display device includes a first line which is arranged across a display portion, and includes a first end portion and a second end portion located at a non-display portion such that the display portion is located between the first and second end portions, a first switch electrically connected to the first end portion, a second switch electrically connected to the second end portion, a first terminal electrically connected to the first end portion via the first switch, and a second terminal electrically connected to the second end portion via the second switch.Type: GrantFiled: January 11, 2022Date of Patent: February 18, 2025Assignee: JAPAN DISPLAY INC.Inventors: Takahiro Ochiai, Hiroshi Inamura, Keita Sasanuma, Kengo Shiragami
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Patent number: 6306647Abstract: A process for converting uridines to 2′,3′-dideoxy-2′,3′-didehydrouridines by reacting acetic anhydride with a 2′,3′-0-alkoxymethylideneuridine intermediate.Type: GrantFiled: December 3, 1993Date of Patent: October 23, 2001Assignee: Ajinomoto Co., Inc.Inventors: Hiroshi Shiragami, Yasuo Irie, Naohiko Yasuda
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Patent number: 6252075Abstract: A process for preparing 7-benzylpurine derivatives is provided. An acetylpurine nucleoside is reacted with a benzyl halide to benzylate the 7-position of the purine base, and an acid is then added to the reaction mixture to hydrolyze the glycoside bond. The 7-benzylpurines may be used to prepare 9-substituted purine derivatives.Type: GrantFiled: May 26, 1999Date of Patent: June 26, 2001Assignee: Ajinomoto Co., Inc.Inventors: Hiroshi Shiragami, Kunisuke Izawa, Keizo Yamashita, Satoshi Katayama
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Patent number: 6245910Abstract: Purine derivatives in which a desired substituent is introduced into the 9-position only are synthesized by first introducing an easily-removable substituent in the 7-position of a purine base of natural purine nucleosides obtained through fermentation or derivatives thereof, then hydrolyzing the ribose moiety to form purine derivatives having the substituent in the 7-position, subsequently introducing the desired substituent in the 9-position, and then removing the substituent in the 7-position.Type: GrantFiled: October 27, 1999Date of Patent: June 12, 2001Assignee: Ajinomoto Co., Inc.Inventors: Kunisuke Izawa, Hiroshi Shiragami, Keizo Yamashita
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Patent number: 6087497Abstract: 9-Substituted purine derivatives of formula (4) ##STR1## are prepared by debenzylating a compound of formula (3): ##STR2##Type: GrantFiled: July 23, 1998Date of Patent: July 11, 2000Assignee: Ajinomoto Co., Inc.Inventors: Kunisuke Izawa, Hiroshi Shiragami, Keizo Yamashita
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Patent number: 5942617Abstract: A process for preparing 7-benzylpurine derivatives is provided. An acetylpurine nucleoside is reacted with a benzyl halide to benzylate the 7-position of the purine base, and an acid is then added to the reaction mixture to hydrolyze the glycoside bond. The 7-benzylpurines may be used to prepare 9-substituted purine derivatives.Type: GrantFiled: September 10, 1997Date of Patent: August 24, 1999Assignee: Ajinomoto Co., Inc.Inventors: Hiroshi Shiragami, Yumiko Uchida, Kunisuke Izawa, Keizo Yamashita, Satoshi Katayama
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Patent number: 5831092Abstract: Purine derivatives in which a desired substituent is introduced into the 9-position only are synthesized by first introducing an easily-removable substituent in the 7-position of a purine base of natural purine nucleosides obtained through fermentation or derivatives thereof, then hydrolyzing the ribose moiety to form purine derivatives having the substituent in the 7-position, subsequently introducing the desired substituent in the 9-position, and then removing the substituent in the 7-position.Type: GrantFiled: February 20, 1996Date of Patent: November 3, 1998Assignee: Ajinomoto Co., Inc.Inventors: Kunisuke Izawa, Hiroshi Shiragami, Keizo Yamashita
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Patent number: 5792868Abstract: Herein is disclosed a novel and industrially advantageous process for synthesizing acyclic nucleosides such as acyclovir and ganciclovir from ribonucleosides, which process comprises adding an acid catalyst and an acid anhydride to a solution of a ribonucleoside such as guanosine and an ester derivative of an acyclic sugar, and heating the mixture, whereby a transglycosilation reaction takes place between the ribose moiety of the ribonucleoside and the ester derivative of the acyclic sugar.Herein is also disclosed an industrially favorable method for the separation of 9-substituted purine nucleosides which are important intermediates for the synthesis of acyclic nucleosides such as acyclovir, ganciclovir, and the like from ribonucleosides, which method comprises crystallizing only the 9-isomer from a solution or suspension containing both a 9-substituted purine nucleoside and a 7-substituted purine nucleoside by cooling the solution or/and by adding a crystallizing solvent thereto.Type: GrantFiled: March 18, 1994Date of Patent: August 11, 1998Assignee: Ajinomoto Co., Inc.Inventors: Kunisuke Izawa, Yoshihito Koguchi, Hiroshi Shiragami
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Patent number: 5688948Abstract: Herein is disclosed a novel and industrially advantageous process for synthesizing acyclic nucleosides such as acyclovir and ganciclovir from ribonucleosides, which process comprises adding an acid catalyst and an acid anhydride to a solution of a ribonucleoside such as guanosine and an ester derivative of an acyclic sugar, and heating the mixture, whereby a transglycosilation reaction takes place between the ribose moiety of the ribonucleoside and the ester derivative of the acyclic sugar.Herein is also disclosed an industrially favorable method for the separation of 9-substituted purine nucleosides which are important intermediates for the synthesis of acyclic nucleosides such as acyclovir, ganciclovir, and the like from ribonucleosides, which method comprises crystallizing only the 9-isomer from a solution or suspension containing both a 9-substituted purine nucleoside and a 7-substituted purine nucleoside by cooling the solution or/and by adding a crystallizing solvent thereto.Type: GrantFiled: May 30, 1995Date of Patent: November 18, 1997Assignee: Ajinomoto Co., Inc.Inventors: Kunisuke Izawa, Yoshihito Koguchi, Hiroshi Shiragami, Yumiko Uchida, Satoshi Takamatsu
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Patent number: 5633366Abstract: Nucleoside derivatives such as 2'-deoxy-2'-bromo-5'-O-acetyl-5-methyluridine, etc., are important intermediates which can be converted into nucleoside derivatives, such as 3'-azido-3'-deoxythymidine, etc., which are useful as medicines.Type: GrantFiled: August 4, 1994Date of Patent: May 27, 1997Assignee: Ajinomoto Co., Inc.Inventors: Satoshi Takamatsu, Hiroshi Shiragami, Yumiko Uchida, Kunisuke Izawa
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Patent number: 5625057Abstract: A process for preparing a 2', 3'-dideoxy-2',3'-didehydropyrimidine nucleoside comprising reacting the pyrimidine ribofuranoside with a trialkyl orthoester to yield the 2',3'-O-alkoxyethylidene derivative; which is reacted with hydrogen bromide in acetic acid or acetyl bromide to yield the 2-deoxy-2'-bromo-3'-acetyl-pyrimidine nucleoside; which is then reduced with zinc to yield the 2',3'-olefin of the pyrimidine nucleoside.Type: GrantFiled: August 25, 1994Date of Patent: April 29, 1997Assignee: Ajinomoto Co., Inc.Inventors: Hiroshi Shiragami, Yumiko Uchida, Kunisuke Izawa
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Patent number: 5466793Abstract: A process for preparing 2',3'-dideoxyinosine comprising reducing a nucleoside of the formula IIIa or IIIb ##STR1## wherein R.sup.2 is hydrogen, C.sub.1-12 acyl, C.sub.1-12 alkyl, C.sub.7-8 aralkyl or a silyl protecting group; X is Cl, Br, or I; R.sub.5 is C.sub.1-12 acyl; H.sub.x is hypoxanthine; with hydrogen in the presence of a palladium catalyst; wherein said reduction is conducted in a solvent containing a base of pH 9-11 and wherein the solvent is acetonitrile, aqueous acetonitrile, aqueous ethyl acetate, or aqueous methanol.Type: GrantFiled: March 30, 1992Date of Patent: November 14, 1995Assignee: Ajinomoto Co., Inc.Inventors: Yutaka Honda, Hiroshi Shiragami, Hisao Iwagami, Masayuki Arai
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Patent number: 5451671Abstract: A crude 2',3'-dideoxynucleoside compound is purified by extracting with an organic solvent, or crystallizing, the 2',3'-dideoxynucleoside compound from a basic aqueous solution having a pH of not less than 12 containing the same. In another embodiment of purification a basic aqueous solution having a pH of not less than 11 of a crude 2',3'-dideoxynucleoside derivative is brought into contact with a nonpolar porous resin, whereby the derivative is adsorbed on the resin, and then the thus adsorbed derivative is desorbed with an aqueous alcoholic solution.2',3'-Dideoxynucleoside compounds which have utility as anti-AIDS drugs or anti-virus drugs can be isolated and purified in high purity and in high yield from their crude products containing impurities.Type: GrantFiled: June 16, 1993Date of Patent: September 19, 1995Assignee: Ajinomoto Co., Inc.Inventors: Hiroshi Shiragami, Masayuki Arai, Kunisuke Izawa, Yutaka Honda, Yasuhiro Tanaka, Toshihide Yukawa, Satoji Takahashi
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Patent number: 5336770Abstract: Herein is disclosed a novel and industrially advantageous process for synthesizing acyclic nucleosides such as acyclovir and ganciclovir from ribonucleosides, which process comprises adding an acid catalyst and an acid anhydride to a solution of a ribonucleoside such as guanosine and an ester derivative of an acyclic sugar, and heating the mixture, whereby a transglycosilation reaction takes place between the ribose moiety of the ribonucleoside and the ester derivative of the acyclic sugar.Type: GrantFiled: July 23, 1992Date of Patent: August 9, 1994Assignee: Ajinomoto Co., Inc.Inventors: Hiroshi Shiragami, Yoshihito Koguchi, Kunisuke Izawa
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Patent number: 5310895Abstract: A method for selective hydrolysis of nucleoside derivatives using cyclodextrin in basic solution is disclosed.Type: GrantFiled: December 21, 1990Date of Patent: May 10, 1994Assignee: Ajinomoto Co., Inc.Inventors: Hiroshi Shiragami, Yasuhiro Tanaka, Hisao Iwagami
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Patent number: 5290927Abstract: A process for preparing 2',3'-dideoxyadenosine of the formula ##STR1## wherein B is adenine, wherein R.sup.1 is hydrogen, C.sub.1-12 acyl, C.sub.1-12 alkyl, C.sub.7-8 aralkyl, or silyl, said process comprising:reducing a nucleoside of the formula IIIa or IIIb ##STR2## wherein R.sup.2 is hydrogen, C.sub.1-12 acyl, C.sub.1-12 alkyl, C.sub.7-8 aralkyl or silyl; X is Cl, Br or I; R.sup.5 is C.sub.1-12 acyl and B is adenine, with hydrogen in the presence of a palladium catalyst and aqueous solvent mixture of acetonitrile or ethyl acetate and water, said aqueous solvent containing a base selected from the group consisting of sodium hydroxide/sodium acetate and sodium carbonate/sodium acetate, wherein said solvent has a pH of 9-11.Type: GrantFiled: March 1, 1989Date of Patent: March 1, 1994Assignee: Ajinomoto Co., Inc.Inventors: Yutaka Honda, Hiroshi Shiragami, Hisao Iwagami, Masayuki Arai
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Patent number: 4970148Abstract: A method of producing dideoxyinosine involving contacting as a substrate 2',3'-dideoxyadenosine with a microorganism which is capable of converting the substrate into 2',3'-dideoxyinosine.Type: GrantFiled: October 7, 1988Date of Patent: November 13, 1990Assignee: Ajinomoto Co., Inc.Inventors: Kenzo Yokozeki, Hideyuki Shirae, Katsunori Kobayashi, Hiroshi Shiragami, Yasuo Irie
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Patent number: 4962193Abstract: A biological process for producing a 2',3'-dideoxynucleoside from 2',3'-dideoxyuridine is disclosed. the 2',3'-dideoxynucleoside can be purified readily using a porous nonpolar resin adsorbent.Type: GrantFiled: December 28, 1988Date of Patent: October 9, 1990Assignee: Ajinomoto Co., Inc.Inventors: Kenzo Yokozeki, Hideyuki Shirae, Hiroshi Shiragami, Yasuo Irie, Naohiko Yasuda, Masaru Otani, Toshiya Tanabe
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Patent number: 4835104Abstract: A biological process for producing a 2',3'-dideoxyncleoside from 2',3'-dideoxyuridine is disclosed. The 2',3'-dideoxynucleoside can be purified readily using a porous nonpolar resin adsorbent.Type: GrantFiled: May 9, 1988Date of Patent: May 30, 1989Assignee: Ajinomoto Co., Inc., Patent & Licensing DepartmentInventors: Kenzo Yokozeki, Hideyuki Shirae, Hiroshi Shiragami, Yasuo Irie, Naohiko Yasuda, Masaru Otani, Toshiya Tanabe