Special Issue

Shigehiko Sugasawa's Special Issues, Vol. 8, No. 1, 1977

73 data found. 31 - 60 listedFirst Previous Next Last
Communication | Special issue | Vol 8, No. 1, 1977, pp. 269 - 276
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DOI: 10.3987/S(S)-1977-01-0269
A Novel Synthesis of 5- or 13-Oxygenated Tetrahydroprotoberberines

Hiroshi Hara, Machiko Hosaka, Osamu Hoshino, and Bunsuke Umezawa*

*Faculty of Pharmaceutical Sciences, Science University of Tokyo, 2641 Yamazaki, Noda, Chiba 278-8510, Japan

Abstract

In order to introduce O-functional groups at the 5- or 13-position in tetrahydroprotoberberine, we tried lead tetraacetate oxidation of (±)-2-hydroxy-3, 10,11-trimethoxy (3)- or (±)-10-hydroxy-2,3,11-trimethoxy (12)-tetrahydroprotoberberine, a moiety of which was 1,2,3,4-tetrahydro-7-hydroxy-6-methoxyisoquinoline convertible to the corresponding 4,7-diacetate via p-quinol acetate.
(±)-2-Phenol (3) yielded a p-quinol acetate (4), which was transformed to several 5-oxygenated tetrahydroprotoberberines (6, 7, 8, 9, 10, and 11). Similarly, some 13-oxygenated derivatives (14, 15 and 16) were prepared from (±)-10-phenol (12).

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 277 - 282
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DOI: 10.3987/S(S)-1977-01-0277
A Biogenetic-type Asymmetric Synthesis of Optically Active Amaryllidaceae Alkaloids: (+)- and (-)-Galanthamine from L-Tyrosine

Kimihiro Shimizu, Kiyoshi Tomioka, Shun-ichi Yamada, and Kenji Koga*

*Faculty of Pharmaceutical Sciences, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan

Abstract

A biogenetic-type asymmetric synthesis of optically active galanthamine (4) from L-tyrosine (L-1) was achieved via the intramolecular phenolic oxidative coupling of norbelladine derivative (5) followed by asymmetric cyclization. Enantiomeric interconversion of narwedine derivative (7) is also described.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 283 - 292
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DOI: 10.3987/S(S)-1977-01-0283
Synthetic Studies on β-Lactam Antibiotics. Part 3. Synthesis of 3-Trifluoromethyl Cephalosporins from Penicillins

Sadao Yamamoto, Nobuhiro Haga, Tsutomu Aoki, Sadao Hayashi, Hiroshi Tanida, and Wataru Nagata*

*Shionogi Research Laboratories, Shionogi & Co. Ltd., Fukushima-ku, Osaka 553-0002, Japan

Abstract

A new synthetic route to 3-trifluoromethyl cephalosporins from penicillin V has been developed. A key intermediate, diphenylmethyl α-{(1R,5R)-3-phenoxymethyl-7-oxa-4-thia-2,6-diazabicyclo[3.2.0]hept-2-en-6-yl}glycolate (4), was easily obtained by ozonolysis of the known olefin 1 and by zinc-acetic acid reduction of its ozonide. Acid cleavage of the thiazoline ring of 4 followed by alkylation with 1,1,1-trifluoro-3-bromoacetone gave compound 6. Reaction of 6 with thionyl chloride and successive treatment with triphenylphosphine afforded the corresponding phosphorane 7, which afforded a desired 3-trifluoromethyl-3-cephem compound 8 by intramolecular Wittig cyclization. The new cephalosporins showed interesting in vitro and in vivo antibacterial activities.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 293 - 298
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DOI: 10.3987/S(S)-1977-01-0293
Studies on Indolizine Derivatives. New Synthetic Mothods of Azacycl[3.2.2]azine Derivatives. XI

Kenji Kurata, Hiroyoshi Awaya, Yoshinori Tominaga, Yoshiro Matsuda, and Goro Kobayashi*

*Faculty of Pharmaceutical Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan

Abstract

N-Bridged 10Π electron ring systems, azacycl[3.2.2]azine derivatives (II, III) were obtained by the photochemical reaction of azaindolizine derivative (I), or by the reaction of I with N-bromosuccinimide (NBS).

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 299 - 305
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DOI: 10.3987/S(S)-1977-01-0299
Displacement Reactions of 2-Alkylsulfonyl-4-chloropyromidine Derivatives with Nucleophiles

Tadahiro Sawayama, Ryuichi Yamamoto, Hiroaki Kinugasa, and Haruki Nishimura*

*Dainippon Pharmaceutical Co., LTD., Enoki 33-94, Suita, Osaka 564, Japan

Abstract

The displacement reactions of 4-chloro-2-ethylsulfonyl-6-phenyl-, 4-chloro-2-ethylsulfonyl- and 4-chloro-6-methyl-2-methylsulfonyl-pyrimidine with ammonia gave the corresponding 4-alkylsulfonyl-2-aminopyrimidine derivatives in which the alkylsulfonyl groups migrated from the 2-position to the 4-position. In addition, it was found that the relative ease of displacement of sulfonyl group versus chloro group in the nucleophilic substitution of 2- and 6-alkylsulfonyl-4-chloropyrimidine derivatives depended on nucleophiles.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 307 - 312
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DOI: 10.3987/S(S)-1977-01-0307
Reactions and Synthetic Applications of β-Ketosulfoxides VIII. Synthesis of 1,1-Dimethylthio-1,2,3,4-tetrahydrocarbazol-2-ones and Their 1,2-Carbonyl Transposition

Yuji Oikawa* and Osamu Yonemitsu

*Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812, Japan

Abstract

β-Ketosulfoxides (9, 10, 11), prepared from indolepropionic acid esters (6, 7, 8) with the K or Li salt of methyl methylthiomethyl sulfoxide, undergo the acid-catalyzed cyclization to yield 1,1-dimethylthio-1,2,3,4-tetrahydrocarbazol-2-ones (14, 15, 16), which were efficiently converted to 1,2,3,4-tetrahydrocarbazol-1-ones (22, 23, 25, 29) through the (alkylative) 1,2-carbonyl transposition. A pyrrolepropionic acid ester (12) similarly gave a 4,5,6,7-tetrahydroindol-4-one (31) via 4,4-dimethylthio-4,5,6,7-tetrahydroindol-5-one (17).

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 313 - 318
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DOI: 10.3987/S(S)-1977-01-0313
Reactions of 3-Chloroindolenines with Some Nucleophiles

Yasumitsu Tamura,* Moon Woo Chun, Hiroshi Nishida, and Masazumi Ikeda

*Faculty of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Toyonaka, Osaka 560-0043, Japan

Abstract

The behavior of 3-chloro-2,3-diphenyl- and 3-chloro-3-methyl-2-phenyl-indolenines towards some nucleophiles in acetic acid was examined. Nucleophiles such as N3- and AcO- underwent irreversible nucleophilic attack, possibly by SN1 mechanism, at the 3-position of the 3-chloroindolenines to give 3-azido- and 3-acetoxy-indolenines, while the nucleophiles such as I-, PhSH, Ph3P, Br-, and SCN- reverted the 3-chloroindolenines to the parent indoles by attacking the chlorine atom. Bromine and thiocyanogen (or their equivalents) thus formed underwent further electrophilic attack at the 6-position of the indoles to give β-bromo- and 6-thiocyanato-indoles, respectively. The above results are discussed in terms of the HSAB principle.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 319 - 323
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DOI: 10.3987/S(S)-1977-01-0319
Synthesis of Pyrazolone Derivatives. XXXII. Studies on (5S,8R)-8,9,9-Trimethyl-5,6,7,8-tetrahydro-5,8-methano-1,2,3-banzotriazine

Isoo Ito,* Noriichi Oda, Shin-ichi Nagai, and Yoshihisa Kudo

*Faculty of Pharmaceutical Sciences, Nagoya City University, Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan

Abstract

Oxidation of 2-amino-4,7-methanoindazole (2) resulted in ring expansion to afford 5,8-methano-1,2,3-benzotriazine (3) which showed prominent central stimulation in mice. Irradiation of 3 provided 3-ethynylcyclopentanecarbonitrile (4).

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 325 - 333
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DOI: 10.3987/S(S)-1977-01-0325
New Prostaglandin Synthon from an 4-Oxa-tricyclo[4.3.0.03,7]-non-8-ene System. A Total Synthesis of (±)-Prostaglandin F2a

Seiichi Takano,* Noboru Kubodera, Hiromitsu Iwata, and Kunio Ogasawara

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan

Abstract

The C-9 tricyclic heterocycle (1) is shown to be a new starting material for a synthesis of (±)-prostaglandin F through the C-9 acetylenic intermediate (10).

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 335 - 338
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DOI: 10.3987/S(S)-1977-01-0335
The Fischer Indole Synthesis with Formic Acid. III. The Reaction with 2-Substituted Adipoins

Takeshi Wakamatsu,* Hiromu Hara, and Yoshio Ban

*Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812, Japan

Abstract

The Fischer indolization of 2-substituted adipoins was effected with formic acid to afford 1-substituted tetrahydrocarbazoles (9) and the corresponding carbazoles (10).

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 339 - 344
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DOI: 10.3987/S(S)-1977-01-0339
Syntheses of Medium-sized Keto-lactam Systems by the Photo-ring-enlargement of N-Substituted Alicyclic Imides

Yuichi Kanaoka,* Haruo Okajima, and Yasumaru Hatanaka

*Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812, Japan

Abstract

Synthetic application of the photo-ring-expansion reaction of N-substituted alicyclic imides 1 was studied and a variety of seven- and eight-membered keto-lactam systems 2 were photochemically synthesized from succinimides and glutarimides.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 345 - 350
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DOI: 10.3987/S(S)-1977-01-0345
Photochemistry of Succinimides with an Ether or a Thioether in Their Side-chains. γ- and δ-Hydrogen Abstraction

Hideo Nakai, Yasuhiko Sato,* Tomishige Mizoguchi, Michio Yamazaki, and Yuichi Kanaoka*

*Organic Chemistry Research Laboratory, Tanabe Seiyaku Co.Ltd., 2-2-50, Kawagishi, Toda, Saitama 335-8505, Japan

Abstract

Upon irradiation certain N-β-sec-alkaxyalkyl-substituted succinimides 4 afforded a pyrrolo[1,2-c]oxazole ring system 5, δ-hydrogen trasfer products, in moderate yields. On the other hand, the thioether analogs 11, 17 gave mixtures of γ-products (13, 14, 15, 18) and γ-products (16, 19), in low yields.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 351 - 356
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DOI: 10.3987/S(S)-1977-01-0351
Quaternization of Pyrizine Monoxides, and Reduction of 1-Methyl-4-oxidopyrizinium Iodides with Sodium Borohydride

Akihiro Ohta,* Mayumi Matsunaga, Noriko Iwata, and Tokuhiro Watanabe

*Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan

Abstract

Quaternization of some methyl- and phenyl-pyrazizne 1-oxides with methyl iodide was investigated. The 1-methyl-4-oxidopyrazinium iodides obtained were treated with sodium borohydride to give N-hydroxypiperazines. The effect of substituents on the quaternization and reduction was discussed.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 357 - 361
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DOI: 10.3987/S(S)-1977-01-0357
Synthesis Utilizing β-Carbonyl System. IV. A Novel Cyclization of 1,9-Diimino-3,7-dicarbonyl and -3,5,7-tricarbonyl Compounds

Ikuo Iijima, Michihiko Miyazaki, Naomasa Taga, and Tadasu Tanaka*

*Biological and Chemical Research Laboratories, Tanabe Seiyaku Co.Ltd., 2-2-50, Kawagishi, Toda, Saitama 335-8505, Japan

Abstract

Bis-(3-methyl-5-isoxazolylmethyl)ketone (1) was converted into 1,9-diimino-3,7-dicarbonyl compounds (3 and 7), which were cyclized to 8-isoquinolinols (5 and 10) by hydrochloric acid in high yields. The compound (12) containing a sterically crowded 1,9-diimino-3,5,7-tricarbonyl system was prepared from the methyl analogue (11) of the ketone (1). The cyclization of 12 afforded the 4-pyridone (13) exclusively.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 363 - 366
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DOI: 10.3987/S(S)-1977-01-0363
Synthesis and Some Reactions of Benzo[f]quinoline-5,6-oxide

Yoshiyasu Kitahara, Koichi Shudo, and Toshihiko Okamoto*

*Faculty of Pharmaceutical Sciences, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan

Abstract

Benzo[f]quinoline-5,6-oxide, a possible active metabolite of benzo[f]quinoline, was prepared and the chemical reactions of the oxide were examined.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 367 - 370
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DOI: 10.3987/S(S)-1977-01-0367
Reaction of Arylhydroxamic Acids with Benzene

Yasuyuki Endo, Toshiharu Ohta, Koichi Shudo, and Toshihiko Okamoto*

*Faculty of Pharmaceutical Sciences, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan

Abstract

Arylhydroxamic acids were reacted with benzene in the presence of trifluoromethanesulfonic acid to form aminobiphenyl derivatives. This reaction was applied to an intramolecular cyclization for the synthesis of dibenz(b,d)azepine and dibenz(b,d)azocine derivatives.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 371 - 376
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DOI: 10.3987/S(S)-1977-01-0371
Synthesis of 4-Substituted Indole Derivatives

Tatsuo Nagasaka, Tohru Tuge, and Sadao Ohki*

*Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan

Abstract

A general synthetic method of 4-substituted indoles was examined. The Fischer indolization of phenylhydrazones (2, 3, 7, and 8) having chlorine on ortho position gave 7-chloro-4-substituted indoles (4, 9, and 10), which were converted to 4-substituted indoles (5 and 13) by catalytic hydrogenation.
Cyclization of 3-(2-ethoxycarbonyl-7-chloroindol-4-yl)propionic acid (10) with polyphosphoric acid (PPA) took place at the 5-position of indole ring to give a tricyclic ketone (14).

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 377 - 382
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DOI: 10.3987/S(S)-1977-01-0377
Photochemical Rearrangement of Fused Zwitterionic Pyridazines and Photochemical Ring Contraction of Fused Pyrimidone

Takao Yamazaki,* Masanori Nagata, Shun-ichi Hirokami, and Sumiko Miyakoshi

*Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Toyama 930-0194, Japan

Abstract

Photolysis of zwitterionic pyridazine (1a-c) in liquid phase afforded pyrimidin-4-ones (2a-c). Photolysis of 6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one (2a) in methanol gave l,6-diaza-3-methoxy-2-methyl-4-oxospiro[4,5]dec-2-ene (3a). Photolysis of (2a) in ethanol gave also 1,6-diaza-3-ethoxy-2-methyl-4-oxospiro[4,5]dec-2-ene (3a’). Hydrolysis of (3a) in methanol or in chloroform containing a small amount of water yielded 2-(α-acetyl-α-methoxyacetyl)-3,4,5,6-tetrahydropyridine (4a).

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 383 - 386
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DOI: 10.3987/S(S)-1977-01-0383
Synthesis of 1,3-Bis(hydroxymethyl)-β-carboline Derivatives

Fumiko Hamaguchi* and Sadao Ohki

*Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan

Abstract

1,3-Bis(hydroxymethyl)-β-carboline derivatives were synthesized by Pictet-Spengler or Bischler-Napieralski reactions, followed by LAH reductions. Among them, 1,3-bis(hydroxymethyl)-2-benzyl-1,2,3,4-tetrahydro-β-carboline (2) hydrochloride was proved to be comparatively effective as an antiflammatory agent.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 387 - 390
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DOI: 10.3987/S(S)-1977-01-0387
Synthesis of 2,3-Bis(trifluromethyl) Indole by the Reaction of Aromatic Nitrones with Hexafluorobut-2-yne

Yoshiro Kobayashi,* Itsumaro Kumadaki, and Tsutomu Yoshida

*Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan

Abstract

Reaction of N-phenyl-α-arylnitrones with hexafluorobut-2-yne was examined. p-Anisyl-, phenyl-, and p-nitrophenyl-nitrones gave 2,3-bis(trifluoromethyl)indole through recyclization of the primary adducts to oxazoline compounds followed by hydrolysis and cyclization, while the isoxazoline compound underwent rearrangement to N,N-dimethyl-N’-phenyl-phenylenediamine compound, when the aryl was a p-dimethyl-aminophenyl group.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 391 - 395
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DOI: 10.3987/S(S)-1977-01-0391
The Synthesis of Cryptopleurospermine, a Benzilic Alkaloid of Cryptocarya pleurosperma

Gordon C. Dunmore,* Richard H. Manske, and Russell Rodrigo

*Guelph-Waterloo Centre for Graduate Work in Chemistry, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada

Abstract

Cryptopleurospermine 5 is synthesised from the aldehydes 13 and 15 through the intermediacy of the trimethylsilyl cyanohydrin of 13 used as a carbonyl anion equivalent.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 397 - 401
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DOI: 10.3987/S(S)-1977-01-0397
A Convenient Method for a Preparation of Oxiranes

Teruo Kutsuma,* Ichigaku Nagayama, Tokuji Okazaki, Tadakatsu Sakamoto, and Sanya Akaboshi

*Research Laboratories, Ohta Pharmaceutical Co., Ltd., Namiki, Kawaguchi, Saitama 332, Japan

Abstract

Oxiranes have been prepared in moderate to excellent yields via an one-pot process under a very mild condition. To an acetonitrile solution of dimethylsulfonium methylide prepared in situ by treating dimethyl sulfide with dimethyl sulfate, followed by sodium methoxide, was added carbonyl compounds at an ambient temperature to give oxiranes.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 403 - 409
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DOI: 10.3987/S(S)-1977-01-0403
Nitration of 1-Cyanoisoquinoline 2-Oxide and Isoquinoline 2-Oxide

Masatomo Hamana* and Hirohisa Saito

*Faculty of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan

Abstract

The nitration of 1-cyanoisoquinoline 2-Oxide (1) with potassium nitrate and sulfuric acid gave 5- and 6-nitro derivatives (2 and 3). The reaction was affected by the concentration of sulfuric acid, and only 3 was obtained from the reaction in 85% acid at 70°, though in a small yield. The nitration with fuming nitric acid (d=1.50) led to the formation of 3 in fairly good yields together with small amounts of 8-nitro derivative (7).
Further, the nitration of isoquinoline 2-oxide (9) with fuming nitric acid was found to give 5-, 6- and 8-nitro derivatives (10, 11 and 12). The orienting effect of the N-oxide function is apparently operative in the formation of 11 and 12.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 411 - 416
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DOI: 10.3987/S(S)-1977-01-0411
Formtion of Some Heterocycles through Ring Transformation of 1-Arylazetidin-2-ones

Shinzo Kano,* Tsutomu Ebata, Yoko Denta, Satoshi Hibino, and Shiroshi Shibuya

*School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan

Abstract

Treatment of 4-hydroxymethyl-1-phenylazetidin-2-one (2) with methanesulfonic acid at room temperature yielded 4-anilino-2-oxotetrahydrofuran (3). On heating 4-benzylcarbamoyl-1-phenylazetidin-2-one (4) in methanesulfonic acid, anilinosuccinimide (6) was obtained. N-Methyl analogue (7) was also obtained from 4-methylcarbamoyl-1-phenylazetidin-2-one (5). 4-(2-Piperidino)-1-(4-methoxyphenyl)azetidin-2-one (9) gave octahydro-4-(4-methoxyphenyl)indolizin-2-one (10) under base-catalyzed conditions. Furthermore, 3-(4-methoxyanilinomethyl)-4-hydroxy-3,4-dihydrocarbostyril (14) was obtained by acid-catalyzed rearrangement of the corresponding 3-suhstituted 1-arylazetidin-2-one (13). 3-(4-Methoxyanilino)-4-hydroxyoctahydroindolizin-2-one (17) was also ohtained by the application of these nucleophilic cleavage of -N-CO- bond to the corresponding 1-arylazetidin-2-one (16).

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 417 - 420
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DOI: 10.3987/S(S)-1977-01-0417
Rection of Ethyl 4-Bromocrotonate with Acetoacetamides

Tetsuzo Kato,* Takuo Chiba, Hiroko Sato, and Tetsuo Ito

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan

Abstract

Ethyl 4-bromocrotonate (1) reacted with acetoacetamide (4) at room temperature to give ethyl 5-carbamoyl-6-oxo-2-heptenoate (10), which was transformed into ethyl 3-acetyl-2-oxopyrrolidine-5-acetate (6) and ethyl 4-carbamoyl-2,3-dihydro-5-methylfuran-2-acetate (8).
Similar reaction of compound 1 with N-methylacetoacetamide (5) afforded ethyl 3-acetylecgoninate (7). Reaction of compound 1 with ethyl acetoacetate (2) gave rise to ethyl 2,3-dihydro-4-ethoxycarbonyl-5-methylfuran-2-acetate (9).

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 421 - 426
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DOI: 10.3987/S(S)-1977-01-0421
Photoarylation. I. Photochemical Synthesisn of Benzothieno[2,3-c][1,x]diazanaphthalene Systems by Intramolecular Dehydrochlorination

Masanao Terashima,* Koichi Seki, Kazuhiko Itoh, and Yuichi Kanaoka

*Faculty of Pharmaceutical Scicences, Higashinihonngakuen University, 1757 Kanazawa, Toubetu-cho, Ishikari-gun, Hokkaodo 061-0212, Japan

Abstract

By intramolecular photoarylation of the amides derived from 3- chlorobenzathiaphene-2-carboxylic acid and aminopyridines, novel polycyclic heteroaromatic systems were synthesized. This approach may be employed as a supplemental method for the oxidative photocyclization.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 427 - 432
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DOI: 10.3987/S(S)-1977-01-0427
Synthesis of 5-Alkyl- and 5-Acyl-uridines via 6-Mercaptouridine (Nucleosides and Nucleotides. XVII)

Hideo Inoue, Masako Takada, Masayo Takahashi, and Tohru Ueda*

*Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812, Japan

Abstract

Several 5-alkyl- and 5-acyl-uridines have been prepared by the allylation or acylation of 2’,3’-O-isopropylidene-6-mercapto-uridine followed by the desulfurization.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 433 - 441
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DOI: 10.3987/S(S)-1977-01-0433
Synthesis of 5- and 6-Aminoimidazo[4,5-b]pyridine Ribonucleossides (A New Type of Adenosine Analogs) by Coupling Reactions

Tokuo Itoh,* Jun‘ichi Inaba, and Yoshihisa Mizuno

*Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812, Japan

Abstract

Synthesis of 5- (2) and 6-amino-3-(β-D-ribofuranosyl)-3H-imidazo[4,5-b]pyridine (3) is described. Ribosylation of 5-acetamidoimidazo[4,5-b]pyridine by “the mercuric cyanide-nitromethane” procedure gave rise to 3-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-3H-derivative 5 (71.2% yield) together with a considerable amount (18.3%) of 1-isomer (7). A trimethylsilylated derivative of 6-nitro- imidazo[4,5-b]pyridine (16) was also ribosylated in the presence of stannic chloride to yield 3-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-3H-derivative (17) (35%) and its positional isomer (19) (10.8%).
The blocked nucleosides (5, 7, 17, and 19) were converted into the corresponding free nucleosides (2, 9, 3, and 21). Physical properties (pKa-values, chemical shifts, uv absorption maxima, and CD-parameters) of the newly prepared nucleosides are also reported.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 443 - 450
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DOI: 10.3987/S(S)-1977-01-0443
The Photo-sensitized Oxidation of Morusin

Taro Nomura* and Toshio Fukai

*School of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan

Abstract

Photo-sensitized oxidation of morusin (I) in the presence of sensitizers (rose bengal, hematoporphyrin) afforded morusinhydroperoxide (II), compound A (III), and two other compounds (IV, V). IV and V were formed via “ene” reaction. Photo-sensitized oxidation of I was carried out in the presence of 2,4,6-tri-tert-butylphenol, a radical quencher, or of triethylene diamine (Dabco), a singlet oxygen quencher. In the former case, II1 and III were not obtained, but IV and XIII, whereas in the latter case, IV and V were not obtained, but II and III. On the basis of the above results, the possible mechanism of the formation of II from I was discussed.

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Communication | Special issue | Vol 8, No. 1, 1977, pp. 451 - 454
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DOI: 10.3987/S(S)-1977-01-0451
The Conformational Analysis of Saturated Heterocycles. Part LXXXIII. Conformational Properties of 2-Oxo-9,10-diazadecalin

Victor J. Baker, Alan K. Katritzky,* and Fernando M. S. Brito Palma

*School of Chemical Sciences, University of East Anglia, Norwich, Northfolk NR4 7TJ, U.K.

Abstract

Proton nmr spectroscopy shows that the newly synthesised bicycle I exists 70% in the trans conformation Ia and 30% in the cis conformation Ib.

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