Patents by Inventor Kazuhisa Narita
Kazuhisa Narita 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: 6221868Abstract: Remedies/preventives (therapeutic or preventive agents) against frequent urination (pollakiuria)/urinary incontinence which contain as an active ingredient compound having a tropone structure or pharmacologically acceptable salt thereof and a novel compound having the tropone structure. The compounds having a tropone structure and having the above pharmacological effects are those represented by, for example, general (1): wherein R1 and R2 represent each a hydrogen atom, lower alkyl group, etc., R3 represents —OR or —NR2; R4, R5 and R12 represents each a hydrogen atom or a lower alkyl group, X represents a nitrogen atom or CH, Z represents —CHAr2, an unsubstituted or substituted phenyl, etc. m is 1 or 2. These compounds are novel ones excluding those wherein Z is —CHAr2.Type: GrantFiled: December 20, 1999Date of Patent: April 24, 2001Assignee: Nippon Kayaku Kabushiki KaishaInventors: Ichiro Koga, Kazuhisa Narita, Atsushi Okada
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Patent number: 5610315Abstract: This invention relates to a process for the preparation of a 6,7-diacyl-7-deacetylforskolin derivative represented by the general formula: ##STR1## wherein R.sup.1 and R.sup.2 each stands for an acyl group and R.sup.3 stands for an aliphatic group having 2 to 3 carbon atoms, which comprises eliminating the acyl group at position 1 in a 1,6,7-triacyl-7-deacetylforskolin derivative represented by the general formula: ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above, by solvolysis. The compound of the formula (I) is expected as medicine.Type: GrantFiled: May 16, 1995Date of Patent: March 11, 1997Assignee: Nippon Kayaku Kabushiki KaishaInventors: Tochiro Tatee, Akira Shiozawa, Hirotaka Yamamoto, Yuh-ichiro Ichikawa, Aya Ishikawa, Chikara Komuro, Kazuhisa Narita
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Patent number: 5324730Abstract: This invention relates to cyclobutane derivatives represented by the following general formula (1) and physiologically acceptable salts thereof: ##STR1## wherein B represents a nucleic acid base derivative, R.sup.1 and R.sup.2 independently represent hydrogen atom, dialkylaminoacyl group, 1,4-dihydro-1-methylnicotinoyl group or substituted phosphoric acid group, provided that either one of R.sup.1 and R.sup.2 is a group other than hydrogen atom.The compounds of this invention exhibit a high oral absorbability and are metabolized in vivo into the compounds of formula (1a). Accordingly, the compounds of this invention are expectedly useful as antiviral agent.Type: GrantFiled: May 22, 1991Date of Patent: June 28, 1994Assignee: Nippon Kayaku Kabushiki KaishaInventors: Yuh-ichiro Ichikawa, Hiroshi Akaba, Yuka Sugawara, Hideo Sugimura, Kazuhisa Narita, Akira Shiozawa, Kouwa Yamashita, Sayuri Kato, Yukihiro Nishiyama, Kenichi Matsubara, Takemitsu Nagahata
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Patent number: 5302730Abstract: This invention relates to a process for the preparation of a 6,7-diacyl-7-deacetylforskolin derivative represented by the general formula: ##STR1## wherein R.sup.1 and R.sup.2 each stands for an acyl group and R.sup.3 stands for an aliphatic group having 2 to 3 carbon atoms, which comprises eliminating the acyl group at position 1 in a 1,6,7-triacyl-7-deacetylforskolin derivative represented by the general formula: ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above, by solvolysis. The compound of the formula (I) is expected as medicine.Type: GrantFiled: June 4, 1993Date of Patent: April 12, 1994Inventors: Tochiro Tatee, Akira Shiozawa, Hirotaka Yamamoto, Yuh-ichiro Ichikawa, Aya Narita, Chikara Komuro, Kazuhisa Narita
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Patent number: 5296492Abstract: A chroman derivative represented by the following general formula [1]: ##STR1## wherein R.sub.1 represents cyano group, nitro group, halogenomethyl group or --SO.sub.2 --X group (X represents lower alkyl group having 1-6 carbon atoms or aryl group); R.sub.2 represents hydrogen atom or OA group (A represents hydrogen atom, nitro group, lower acyl group having 1-6 carbon atoms, arylcarbonyl group, lower alkylsulfonyl group having 1-6 carbon atoms, arylsulfonyl group, arylalkyl group, tetrahydropyranyl group, lower alkoxycarbonyl group having 1-6 carbon atoms, arylalkoxycarbonyl group or silyl derivative group); R.sub.3 singly represents a hydrogen atom; or R.sub.3 forms a bond jointly with R.sub.2 ; and R.sub.4, R.sub.5, R.sub.6 and R.sub.7 each represent hydrogen atom, vinyl group, formyl group, --Y--(OA).sub.n group (Y represents straight or branched chain alkylene group having 1-6 carbon atoms or lower alkenyl group having 1-6 carbon atoms, A is as defined above, and n represents an integer of 1-3.Type: GrantFiled: June 3, 1992Date of Patent: March 22, 1994Assignee: Nippon Kayaku Kabushiki KaishaInventors: Akira Shiozawa, Atsuro Inubushi, Kazuhisa Narita, Yukihiro Sagawa, Makoto Hosono, Masashi Iida
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Patent number: 5166397Abstract: This invention relates to a process for producing an optically active cyclobutylamine which comprises reacting a racemic modification of cyclobuthylamine represented by the following general formula [I]: ##STR1## wherein R.sup.1 and R.sup.2 represent each a hydrogen atom or a protecting group; with an optically active N-acylphenylglycine to thereby give two corresponding diastereomeric salts, crystallizing the more difficultly soluble diastereomeric salt and isolating the corresponding optically active cyclobutylamine from the diastereomeric salt thus crystallized. The optically active substances of the compound of the above general formula [I] are useful as, for example, an intermediate in the synthesis of 9-[(1R, 2R, 3S)-2,3-bis(hydroxymethyl)-1-cyclobutyl]guanine which is expected as an antiviral agent.Type: GrantFiled: September 10, 1991Date of Patent: November 24, 1992Assignee: Nippon Kayaku Kabushiki KaishaInventors: Kazuhisa Narita, Masashi Nagai, Hideo Sugimura, Yukihiro Sagawa, Akira Shiozawa
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Patent number: 5103022Abstract: A process for producing an optically active aminoketone derivative having a central muscle relaxant activity is described wherein a racemic mixture of the aminoketone is reacted with optically active L-acetylphenylglycine and then isolating the optically active L-aminoketone from the diastereomeric salts formed by the reaction.Type: GrantFiled: December 18, 1990Date of Patent: April 7, 1992Assignee: Nippon Kayaku Kabushiki KaishaInventors: Akira Shiozawa, Kazuhisa Narita, Shuji Kurashige, Takeji Sakasai, Kazuo Ohtsuki, Hideo Sugimura, Hirotaka Yamamoto
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Patent number: 5057535Abstract: A new class of aminoketone derivatives according to the formula: ##STR1## and certain propiophenone derivatives in particular, corresponding to the formula: ##STR2## having central muscle relaxant activity.Type: GrantFiled: September 25, 1987Date of Patent: October 15, 1991Assignee: Nippon Kayaku Kabushiki KaishaInventors: Akira Shiozawa, Michio Ishikawa, Giichi Izumi, Katsuhiko Sakitama, Kazuhisa Narita, Shuji Kurashige, Takeji Sakasai, Kazuo Ohtsuki, Hideo Sugimura, Hirotaka Yamamoto
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Patent number: 4954642Abstract: This invention relates to forskolin derivatives, their physiologically acceptable salts, and a process for producing these compounds. The forskolin derivative is represented by the general formula ##STR1## wherein; I. when R.sup.1 is hydrogen and R.sup.4 is vinyl, ethyl, or cyclopropyl,(1) either of R.sup.2 and R.sup.3 denotes a residue represented by the formula ##STR2## wherein each of R.sup.5 and R.sup.6 denotes hydrogen or lower alkyl or R.sup.5 and R.sup.6 combine with each other to form a lower alkylene chain which may or may not contain an oxygen or nitrogen atom and m is an integer of 1 to 5, and the other one of R.sup.2 and R.sup.3 denotes hydrogen or a residue represented by the formula CO(CH.sub.2).sub.n X, X being hydrogen or ##STR3## wherein, each of R.sup.7 and R.sup.8 denotes hydrogen or lower alkyl or R.sup.7 and R.sup.8 combine with each other to form a lower alkylene chain which may or may not contain an oxygen or nitrogen atom, and n being an integer of 1 to 5, or(2) R.sup.Type: GrantFiled: May 30, 1989Date of Patent: September 4, 1990Assignee: Nippon Kayaku Kabushiki KaishaInventors: Tochiro Tatee, Takashi Takahira, Kouwa Yamashita, Masao Sakurai, Akira Shiozawa, Kazuhisa Narita