Patents by Inventor Yoshikazu Takehira
Yoshikazu Takehira 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: 6268515Abstract: A process for preparing a 3-hydroxy-&ggr;-butyrolactone derivative represented by the following formula (1): wherein R is C1-C6 alkyl, 3 to 6-membered cycloalkyl, aralkyl, 2-alkenyl, acyl, &agr;-hydroxyalkyl, alkoxycarbonylalkyl or alkoxycarbonyl, which is characterized in treating 3-hydroxy-&ggr;-butyrolactone with a metal salt of hexamethyldisilazane and then, reacting it with an electrophilic reagent, optionally in the presence of a reaction promoter.Type: GrantFiled: June 23, 2000Date of Patent: July 31, 2001Assignee: Daiso Co., Ltd.Inventors: Kazumasa Hinoue, Yoshiro Furukawa, Shigeo Katsumura, Yoshikazu Takehira
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Patent number: 5374373Abstract: A ferroelectric liquid crystal device having a pair of substrates each provided with voltage application means, an orientation control layer formed on at least one of the substrates, and a layer of ferroelectric liquid crystal composition formed between the pair of substrates, the device being characterized in that the ferroelectric liquid crystal composition comprises at least one compound (a) having an optically active group of the formula (I): ##STR1## and at least one compound (b) which is reverse to the compound (a) in the direction of a helical pitch induced in a nematic phase, the liquid crystal composition exhibiting at least a smectic C phase, smectic A phase and nematic phase at least 20 .mu.m in helical pitch.Type: GrantFiled: May 5, 1993Date of Patent: December 20, 1994Assignees: Sharp Kabushiki Kaisha, Daiso Co., Ltd.Inventors: Mitsuhiro Koden, Tomoaki Kuratate, Fumiaki Funada, Kazuhiko Sakaguchi, Yoshikazu Takehira, Yutaka Shiomi, Tohru Kitamura
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Patent number: 5324450Abstract: An optically active glycidyl ether, which is useful in making .gamma.-lactone containing liquid crystalline compounds, the ether having the following formula: ##STR1## wherein R.sup.1 is a group selected from the group consisting of ##STR2## n is 0 or 1; e is 1; R.sup.3 is an alkyl group having 1 to 15 carbon atoms; and the symbol * is an asymmetric carbon atom.Type: GrantFiled: May 24, 1993Date of Patent: June 28, 1994Assignee: Daiso Co., Ltd.Inventors: Kazuhiko Sakaguchi, Naoya Kasai, Yoshikazu Takehira, Tohru Kitamura, Yutaka Shiomi
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Patent number: 5308540Abstract: Liquid crystalline compounds having an optionally active .gamma.-lactone ring of the formula: ##STR1## wherein R.sup.1 is a group selected from the group consisting of ##STR2## n and e are each independently 0 or 1; R.sup.3 is an alkyl group having 1 to 15 carbon atoms; R.sup.2 is a group of the formula: --(CO).sub.m --R.sup.4 ; m is 0 or 1; R.sup.4 is hydrogen atom or an alkyl having 1 to 15 carbon atoms; and the symbol * is an asymmetric carbon atom, and an intermediate thereof, and process for the production of the same.Type: GrantFiled: July 16, 1992Date of Patent: May 3, 1994Assignee: Daiso Co., Ltd.Inventors: Kazuhiko Sakaguchi, Naoya Kasai, Yoshikazu Takehira, Tohru Kitamura, Yutaka Shiomi
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Patent number: 5250715Abstract: The present invention provides an optically active 2-methylenepentane derivative represented by the general formula ##STR1## (wherein R.sup.1 is a protective group for hydroxyl, R.sup.3 is a protective group for hydroxyl, X is a halogen atom or R.sup.4 SO.sub.3 group (wherein R.sup.4 is an alkyl or an aryl), and the symbol * represents an asymmetric carbon atom).Type: GrantFiled: March 30, 1992Date of Patent: October 5, 1993Assignee: Daiso Co., Ltd.Inventors: Takashi Takahashi, Yoshikazu Takehira
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Patent number: 5223646Abstract: Improved process for producing an optically active atenolol useful as a .beta.-adrenergic blocker for the treatment of angina pectoris, arrhythmia and hypertension, which comprising reacting a phenol compound with an optically active epihalohydrin to give an intermediate, optically active glycidyl ether compound, followed by reacting the intermediate with isopropylamine, and purification method of the optically active atenolol in high yield by means of forming a salt of atenolol with a Br nsted's acid whereby the salt of optically active atenolol having high optical purity can be separated from the salt of racemic atenolol by solid-liquid separation method.Type: GrantFiled: April 21, 1992Date of Patent: June 29, 1993Assignee: Daiso Company, Ltd.Inventors: Yoshikazu Takehira, Nobuaki Saragai, Kazuhiro Kitaori
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Patent number: 5216187Abstract: The present invention provides an optically active 2-methylenepentane derivative represented by the general formula ##STR1## (wherein R.sup.1 is a protective group for hydroxyl, R.sup.3 is a protective group for hydroxyl, X is a halogen atom or R.sup.4 SO.sub.3 group (wherein R.sup.4 is an alkyl or an aryl), and the symbol * represents an asymmetric carbon atom).Type: GrantFiled: July 9, 1991Date of Patent: June 1, 1993Assignee: Daiso Co., Ltd.Inventors: Takashi Takahashi, Yoshikazu Takehira
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Patent number: 5215678Abstract: A ferroelectric liquid crystal composition comprising at least one compound represented by the formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are, the same or different, a straight-chain or branched-chain alkyl group having 1 to 15 carbon atoms, and each asterisk represents an asymmetric carbon atom, and at least one compound represented by the formula (II): ##STR2## wherein R.sup.3 and R.sup.4 are, the same or different, a straight-chain or branched-chain alkyl group having 1 to 15 carbon atoms, and each asterisk represents an asymmetric carbon atom, and liquid crystal device incorporating same.Type: GrantFiled: December 10, 1991Date of Patent: June 1, 1993Assignees: Sharp Kabushiki Kaisha, Daiso Co.Inventors: Mitsuhiro Koden, Tomoaki Kuratate, Fumiaki Funada, Kazuhiko Sakaguchi, Naoya Kasai, Yoshikazu Takehira, Tohru Kitamura, Yutaka Shiomi
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Patent number: 5200538Abstract: The present invention provides an optically active 2-methylenecyclopentanone derivative represented by the general formula ##STR1## (wherein R.sup.1 is a protective group for hydroxyl, and the symbol * represents as asymmetric carbon atom).Type: GrantFiled: May 27, 1992Date of Patent: April 6, 1993Assignee: Daiso Co., Ltd.Inventors: Takashi Takahashi, Yoshikazu Takehira
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Patent number: 5180844Abstract: The present invention provides an optically active 2-methylenecyclopentanone derivative represented by the general formula ##STR1## (wherein R.sup.1 is a protective group for hydroxyl, and the symbol * represents an asymmetric carbon atom).Type: GrantFiled: July 9, 1991Date of Patent: January 19, 1993Assignee: Daiso Co., Ltd.Inventors: Takashi Takahashi, Yoshikazu Takehira
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Patent number: 5136066Abstract: The present invention provides a process for preparing an optically active cyclopentenone derivative represented by the formula ##STR1## by oxidizing an optically active cyclopentanone derivative represented by the formula ##STR2## with an oxidizing agent, and subsequently subjecting the oxidized compound to an elimination reaction. (In the above formulae, R.sup.1 is a protective group for hydroxyl, R.sup.5 is straight-chain or branched alkyl, alkenyl, alkynyl or alkylaryl having 5 to 22 carbon atoms and containing or not containing oxygen, sulfur or silicon, R.sup.6 is alkyl, aryl or heterocyclic group having or not having a substituent, Z is selenium or sulfur, and the symbol * represents an asymmetic carbon atom.Type: GrantFiled: July 9, 1991Date of Patent: August 4, 1992Assignee: Daiso Co., Ltd.Inventors: Takashi Takahashi, Yoshikazu Takehira
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Patent number: 5130482Abstract: Improved process for producing an optically active atenolol useful as a .beta.-adrenergic blocker for the treatment of angina pectoris, arrhythmia and hypertension, which comprising reacting a phenol compound with an optically active epihalohydrin to give an intermediate, optically active glycidyl ether compound, followed by reacting the intermediate with isopropylamine, and purification method of the optically active atenolol in high yield by means of forming a salt of atenolol with a Bronsted's acid whereby the salt of optically active atenolol having high optical purity can be separated from the salt of racemic atenolol by solid-liquid separation method.Type: GrantFiled: December 7, 1990Date of Patent: July 14, 1992Assignee: Daiso Company, Ltd.Inventors: Yoshikazu Takehira, Nobuaki Saragai, Kazuhiro Kitaori
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Patent number: 5026506Abstract: A chiral smectic liquid crystal composition comprising one or more liquid crystalline compound exhibiting a smectic C phase and at least one compound of the formula (A): ##STR1## wherein R.sub.1 and R.sub.2 are same or different and are each a straight-chain or branched-chain alkyl group having 1 to 12 carbon atoms, and each C marked with * is an optically active carbon atoms, and a liquid crystal display device containing it.Type: GrantFiled: March 3, 1989Date of Patent: June 25, 1991Assignees: Sharp Kabushiki Kaisha, Daiso Co., Ltd.Inventors: Mitsuhiro Koden, Tomoaki Kuratate, Fumiaki Funada, Kazuhiko Sakaguchi, Naoya Kasai, Yoshikazu Takehira
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Patent number: 4909957Abstract: Liquid crystalline compounds having an optically active .gamma.-lactone ring of the formula: ##STR1## wherein R.sup.1 is a group selected from the group consisting of ##STR2## n and e are each independently 0 or 1; R.sup.3 is an alkyl group having 1 to 15 carbon atoms; R.sup.2 is a group of the formula: --(CO).sub.m --R.sup.4 ; m is 0 or 1; R.sup.4 is hydrogen atom or an alkyl having 1 to 15 carbon atoms; and the symbol * is an asymmetric carbon atom, and an intermediate thereof, and process for the production of the same.Type: GrantFiled: September 7, 1988Date of Patent: March 20, 1990Assignee: Daiso Co., Ltd.Inventors: Kazuhiko Sakaguchi, Naoya Kasai, Yoshikazu Takehira, Tohru Kitamura, Yutaka Shiomi