Regular Issue

Vol. 29, No. 7, 1989

28 data found. 1 - 28 listed
Communication | Regular issue | Vol 29, No. 7, 1989, pp.1221-1224
Published online:
DOI: 10.3987/COM-89-4927
2-Amino-3-cyano-4,5-dimethylfuran as Precursors to Butenolides and Arylacetic Acids

Hooshang Kooshakabadi, Walter F. Schmidt, Stephen J. Cutler, Fiesal M. El-Kabbani, and C. DeWitt Blanton, Jr.*

*Department of Medical Chemistry and Pharmacognosy, College of Pharmacy, The University of Georgia, Athens, Georgia 30602, U.S.A.

Abstract

A facile synthesis of butenolides and arylacetic acids via a Michael reaction of the title compound at C(5) is reported.

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Communication | Regular issue | Vol 29, No. 7, 1989, pp.1225-1232
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DOI: 10.3987/COM-89-4940
A Convenient, One-pot Azulene Synthesis from Cyclohepta[b]furan-2-ones and Vinyl Ether and Its Analogues (I). Vinyl Ethyl Ether, Vinyl Acetates, Dihydrofurans, and Dihydropyrans as Reagent

Tetsuo Nozoe,* Paw-Wang Yang, Chi-Phi Wu, Tin-Shan Huang, Te-Hsiang Lee, Harue Okai, Hidetsugu Wakabayashi,* and Sumio Ishikawa

*Department of Chemistry, Faculty of Science, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japan

Abstract

Variously functionalized azulene derivatives (more than 40) were synthesized in one-pot and in good yields by the reaction of cyclohepta [b] furan-2-one derivatives with vinyl ethyl ether, vinyl acetate, isopropenyl acetate, dihydropyrans, and dihydrofurans on heating at 160-190 °C in aprotic solvent. Structures of formal cycloadducts in two cases were determined, and a possible pathway of the reaction is discussed.

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Communication | Regular issue | Vol 29, No. 7, 1989, pp.1233-1236
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DOI: 10.3987/COM-89-4986
Synthesis of Novel Chiral2,3-Dihydro-1,3,4-thiadiazoles with Extremely High Optical Rotations: X-Ray Crystal Structure of (2R)-D-Mandelyl-5-methylthio-2-phenyl-2,3-dihydro-1,3,4-thiadiazole

Kouhei Toyooka,* Yoshiyuki Takeuchi, Zenei Taira, and Seiji Kuboto

*Faculty of Pharmaceutical Sciences, University of Tokushima, Sho-machi, Tokushima 770-8505, Japan

Abstract

The reaction of 4-bromobenzaldehyde methylthio (thiocarbonyl)-hydrazone with chiral 5-phenyl-1,3-dioxolane-2,4-dione in the presence of trifluoroacetic acid gave chiral 2-(4-bromophenyl)-3-mandelyl-2,3-dihydro-1,3,4-thiadiazoles with extremely high optical rotations; the absolute configuration of the 2,3-dihydro-1,3,4-thiadiazole (2) was established by single crystal X-ray analysis.

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Communication | Regular issue | Vol 29, No. 7, 1989, pp.1237-1240
Published online:
DOI: 10.3987/COM-89-4995
Preparation of β-Lactams from β-Amino Acids with Di-2-pyridyl Sulfite

Sunggak Kim,* Kyu Yang Yi, and Ja-Young Namkung

*Department of Chemistry, Korea Advanced Institute of Science and Technology, 373-1, Kusung-Dong, Yusung-Gu, Taejon, 305-701, Korea

Abstract

β-Lactams are conveniently prepared in high yields by the reaction of β-amino acids with di-2-pyridyl sulfite in acetonitrile under very mild conditions.

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Communication | Regular issue | Vol 29, No. 7, 1989, pp.1241-1242
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DOI: 10.3987/COM-89-5021
The First Synthesis of 4,5-Di-t-buthylpyridazine

Juzo Nakayama* and Atsushi Hirashima

*Department of Chemistry, Faculty of Science, Saitama University, Saitama, Saitama 338-8570, Japan

Abstract

3,4-Di-t-butylthiophene 1,1-dioxide (1) reacts with 2 equiv. of 4-phenyl-1,2,4-triazoline-3,5-dione in refluxing toluene to give the bis-adduct 4 in 87% yield. KOH-Induced methanolysis of 4, followed by spontaneous air-oxidation and nitrogen extrusion of the resulting hydrazo compound 5, affords 4,5-di-t-butylpyridazine (7) directly in one-pot in 80% yield.

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Communication | Regular issue | Vol 29, No. 7, 1989, pp.1243-1246
Published online:
DOI: 10.3987/COM-89-5022
Intramolecular Cycloadditions with Isobenzofuran -VIII. Synthesis of Precurosors via an Oppé Reaction

Knut Hildebrandt and Willy Friedrichsen*

*Institut für Organische Chemie, Universität Kiel, Olshausenstrasse. 40, D-24098 Kiel, Germany

Abstract

The diazoesters 3 and 9 were prepared via an Oppé reaction. Generation of isobenzofurans (e.g. 4) and subsequent intramolecular Diels-Alder reaction yields polycyclic systems (6, 10). Compound 10 can be transformed into an 11-oxasteroid 14.

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Communication | Regular issue | Vol 29, No. 7, 1989, pp.1247-1249
Published online:
DOI: 10.3987/COM-89-5026
Enantioselective Synthesis of (+)-Acetylphomalactone from 2-Furylcarbinols

Tetsuji Kametani, Yoko Tatsuzaki, Masayoshi Tsubuki, and Toshio Honda*

*Faculty of Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan

Abstract

A facile synthesis of (+)-acetylphomalactone (1) has been developed in seven steps employing the kinetic resolution of the racemic secondary furylcarbinol (2) as a key reaction.

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Communication | Regular issue | Vol 29, No. 7, 1989, pp.1251-1254
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DOI: 10.3987/COM-89-5037
A New and Simple Synthesis of 1-Hydroxyindole Derivatives

Masanori Somei* and Toshiya Kawasaki

*Faculty of Pharmaceutical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-0934, Japan

Abstract

A new and straightforward simple synthesis method for 1-hydroxyindole derivatives is developed.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1255-1261
Published online:
DOI: 10.3987/COM-89-S129
Palladium Homogeneous and Supported Catalysis: Synthesis of Functional Acetylenics and Cyclisation to Heterocycles

Didier Villemin* and Delphine Goussu

*I.S.M.Ra, URA 480 C.N.R.S., Université d’Orléans, 5 avenue d’Edimbourg, F-14032 Caen Cedex, France

Abstract

Homogeneous and supported palladium catalysis is a good way to synthesize functional orthu-phenylacetylenes from acetylenes and orthohalogenated aromatics. Functional ortho-phenylacetylenes are cyclised into various benzoheterocyclic compounds.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1263-1273
Published online:
DOI: 10.3987/COM-89-4910
Cyclization of Allyl Silanes — A Novel Approach to 2-Azabicyclo[3.3.0]octanes

Jean-Claude Gramain and Ronald Remuson*

*Laboratoire de Chimie des Substances Naturelles, U.A. CNRS 485, Université Blaise Pascal (Clemont II), 63177 Aubière Cedex, France

Abstract

The methodology which consists in the electrophilic substitution of α-acyl and N-acyl iminium ions on allyl silanes has been used to accede to 2-azabicyclo[3.3.0] octane derivatives and realizes a formal total synthesis of azacarboprostacyclin analogs.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1275-1282
Published online:
DOI: 10.3987/COM-89-4922
Synthesis of 5β-Androsta-17β-(1’-oxocyclohex-2’-en-3’-yl)-3β,14β,diol-3-β-D-glucopyranoside, a Potent Cardiac Glucoside with High Safety Margin

Uttam K. Pati* and Karel Wiesner

*Natural Products Research Center, Department of Chemistry, University of New Brunswick, Bag Service #45222, Fredericton, New Brunswick, E3b 5A3, Canada

Abstract

Starting from testosterone 1, an efficient preparation of a cardioactive glucoside 13 with a modified 17β- functionality is described. The glucoside 13, in spite of no lactone group at the 17β- position, is found to be potent and showed a high margin of safety.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1283-1292
Published online:
DOI: 10.3987/COM-89-4964
Generation and Cyclization of Nitrilium Ions from Amides

Robert E. Gawley* and Sanjay R. Chemburkar

*Department of Chemistry, College of Arts of Sciences, University of Miami, 1301 Memorial Dr., Coral Gables, FL 33124-0431, U.S.A.

Abstract

Amides are shown to be eflcient precursors to nitrilium ions, which may cyclize onto styryl terminators to form pyrrolines. Comparison of several cyclization substrates defines the steric and stereoelectronic scope and liminations of the process. Appropriately functionalized pyrrolines may be reduced with chiral borohydrides and further elaborated to nonracemic pyrrolizidines and indolizidines.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1293-1300
Published online:
DOI: 10.3987/COM-89-4967
Two New Diterpenoid Alkaloids from Delphinium pacific giant and Revised 13C-Nmr Assignment of Delpheline

Hideo Bando, Koji Wada, Junko Tanaka, Sachie Kimura, Ekumi Hasegawa, and Takashi Amiya

*Hokkaido College of Pharmacy, 7-1 Katsuraoka-cho, Otaru 047-02, Japan

Abstract

Two new C19-diterpenoid alkaloids, paciline (1) and pacinine (2), and a known alkaloid, delpheline (1) were isolated from Delphinium pacific giant. Structures of those alkaloids were determined on the basis of their spectral data and chemical correlation with delpheline (3). Paciline (1) was afforded by methylation of delpheline (3) and pacinine (2) was afforded by oxidation of delpheline (3). 13C-Chemical shifts assigned to C-1, C-9, C-10, C-14, and C-16 of delpheline (3) were revised on the basis of 2D nmr measurement.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1301-1308
Published online:
DOI: 10.3987/COM-89-4968
Heterocyclic Photorearrangements - Photochemical Behavior od Some 3-Acetylamino-5-aryl-1,2,4-oxadiazoles. A Photoinduced iso-Heterocyclic Rearrangement

Silvestre Buscemi, Gabriella Macaluso, and Nicolò Vivona*

*Dipartimento Chimica Organica, Università digli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy

Abstract

The photochemical behaviour of some 3-acetylamino-5-aryl-1,2,4-oxadiazoles in methanol at 254 nm has been investigated. A photoinduced rearrangement to the corresponding 2-acetylaminoquinazolin-4-one derivatives has been pointed out and explained as proceeding through a preliminary iso-heterocyclic photoinduced rearrangement to the corresponding 3-aroylamino-5-methyl-1,2,4-oxadiazoles,followed by a subsequent photoreaction of the latter. Some mechanistic considerations are reported.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1309-1316
Published online:
DOI: 10.3987/COM-89-4976
Pyridazines XLII. On the Synthesis of N-5-substitutes Pyridazino[4,5-b]quinolin-10(5H)-ones

Norbert Hainder, Gottfried Heinisch,* and Ivo Volf

*Institute of Pharmaceutical Chemistry, University of Vienna, Währinger Strasse 10, A-1090 Vienna, Austria

Abstract

Procedures for the preparation of diazaacridones 6 bearing branched or higher alkyl chains at N-5 were developed utilizing the pyridazinone 7 as a key compound. An unexpected side reaction observed in the course of the synthesis of 7 is described.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1317-1323
Published online:
DOI: 10.3987/COM-89-4977
Condensed Thienopyrimidines 5. Studies on the Thermal Cyclization of Various ortho-Formylthiophenecarbamates with Ethanolamine

Mitsuo Sugiyama, Toshiaki Sakamoto, and Hiroshi Fukumi*

*Medicinal Chemistry Research Laboratories, Sankyo Co., Ltd., 1-2-58 Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan

Abstract

Condensatlo of various ortho-formylthiophenecarbamates with ethanolamine afforded angular annelated tricyclic oxazolothienopyrimidine derivatives, 2,3,6,9b-tetrahydro-5H-oxazolo [3,2-c] thieno [2,3-e]-, and [3,2-e] pyrimidin-5-ones (2), which have new heterocyclic ring systems. The reaction mechanism on the formation of 2 is discussed.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1325-1329
Published online:
DOI: 10.3987/COM-89-4980
Nucleophilic Aromatic substitution in 4,5-Dicyanoimidazoles

Paul G. Apen and Paul G. Rasmussen*

*Department of Chemisry, University of Michigan , 930 North University, Ann Arbor, MI 48109-1055, U.S.A.

Abstract

Nucleophilic aromatic substitution reactions in 4,5-dicyanoimidazoles are described. For example, reaction of 1-methyl-2-bromo-4,5-dicyanoimidazole (5) with good nitrogen nucleophiles, such as n-butylamine, piperidine and imidazole, gave the highly functionalized 2-substituted 1-methyl-4,5-dicyanoimidazoles (6-10). Reaction of 5 with weaker nucleophiles, such as carbazole, did not occur.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1331-1334
Published online:
DOI: 10.3987/COM-89-4982
An Unusual Photochemical Reaction of Indene with Furan and Thiophene Derivatives

Maurizio D’Auria,* Antonella De Mico, and Franco D’Onofrio

*Centro CNR per lo Studio della Chimica delle Sostanze Organiche Naturali, Dipartmento di Chimica, Università degli Studi di Roma "La Sapienza", Piazzale Aldo Moro 5, 00185 Roma, Italy

Abstract

2-Indenylfuran and -thiophene derivatives are synthesized through a photochemical approach.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1335-1342
Published online:
DOI: 10.3987/COM-89-4985
The Formation of 1-Methyl-3-nicothinoylpyrrolidine from Nicotine-1’-oxide

Nancy J. Joyce and Edward Leete*

*Natural Products Labratory, Department of Chemistry, University of Minnesota, Misseapolis, Minnesota 55455, U.S.A.

Abstract

Several new compounds were obtained when nicotine-1’-oxide was treated with ferric nitrate in the presence of tartaric acid, the most unexpected being 1-methyl-3-nicotinoylpyrrolidine. A unified mechanism is proposed to explain the formation of this substance and other pyridine derivatives.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1343-1348
Published online:
DOI: 10.3987/COM-89-4988
On the Protonation Site of Rauwolfia Alkaloids in Highly Concentrated Sulphuric and Solutions

María A. Muñoz, Carmen Carmona, Jose Hidalgo, Manuel Balón, and Manuel López-Poveda

*Departamento de Química Física, Instituto de Ciencias de los Materiales, Universidad de Sevilla-C.S.I.C., 41012-Sevilla, Spain

Abstract

13C-Nmr spectroscopy has been used to investigate the protonation site of the Rauwolfia alkaloids yohimbine, reserpine and reserpiline in highly concentrated sulphuric acid solutions (~189M H2SO4). The chemical shifts which occur upon protonation reveal unambiguously that the alkaloids protonate on C-7, the β-position with respect to their indole ring, and suggest that the indoleninium cations of the methoxy-substituted alkaloids have principally an enamine structure.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1349-1354
Published online:
DOI: 10.3987/COM-89-4992
Reaction of o-Isocyanatobenzoyl Chloride with Cyanotrimethylsilane. Formation of 4-Oxo-4H-benzoxazine-2-carbonitrile and Its Ring Transformation to 3,4-Dihydro-1H-1,3,4-benzotriazepine-2,5-diones

Masahiko Takahashi* and Akira Hiratsuka

*Department of Materials Sciences, Faculty of Engineering, Ibaraki University, 4-12-1 Nakanarusawamachi, Hitachi, Ibaraki 316-8511, Japan

Abstract

Reaction of O-isocyanatobenzoyl chloride (1) with cyanotrimethylsilane gave 4-oxo-4H-3,1-benzoxazine-2-carbonitrile (2), which was transformed to 3,4-dialkyl-3,4-dihydro-1H-1,3,4-benzotriazepine-2,5-diones (9) on treatment with 1,2-dialkylhydrazines. Halogenation of 9 gave 7-halotriazepines 10.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1355-1368
Published online:
DOI: 10.3987/COM-89-4993
Syntheses and Chiroptical Properties of Some New N-(5-benzofurazanoyl)-L-α-amino Acids and Esters

Sadiq A. Saleh* and Mustafa M. El-Abadelah

*Chemistry Department, Yarmouk University, Irbid, Jordan

Abstract

A series of new N-(5-benzofurazanoyl)-L-α-amino acids (Ia) and esters (Ib) have been prepared. The cd spectra of the L-aliphatic and L-aromatic amino acid derivatives (Ia) display, in organic solvents, sign inversion for the measured Cotton effect (CE) bands. Comparable trend is also observed for the respective amino ester analogues (Ib). This chiroptical behaviaur might be attributed to differences in conformational equilibria of either series. 1H-Nmr and ms spectra of the title compounds are discussed.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1369-1378
Published online:
DOI: 10.3987/COM-89-4998
Four New Prenylated Flavonoids from Aerial Parts of Glycyrrhiza uralensis

Toshio Fukai, Qing-Hua Wang, and Taro Nomura*

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

Abstract

Three new prenylated isoflavones were isolated from the aerial parts of Glycyrrhiza uralensis Fisch. et DC. (Leguminosae) and the structures of the new compounds, gancaonins B, C, and D, were elucidated as 5,7,3’-trihydroxy-4’-methoxy-6-prenylisoflavone, (E)-5,7,4’-trihydroxy-8-(3-hydroxymethyl-2-butenyl)isoflavone, and (E)-5,7,3’-trihydroxy-4’-methoxy-8-(3-hydroxymethyl-2-butenyl)isoflavone, respectively. Gancaonin E, from the same material, was confirmed as 5,7,3’,4’-tetrahydroxy-8,5’-diprenylflavanone. Gancaonin A, 5,7-dihydroxy-4’-methoxy-6-prenylisoflavone, was isolated for the first time as a natural product. Four known phenolic compounds, scopoletin, formononetin, lupiwighteone, and sigmoidin B, were also isolated.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1379-1382
Published online:
DOI: 10.3987/COM-89-5000
Synthesis of 3,5,6-Trisubstitutued 1,2,4-Triazines from 3,6-Disubstituted 1,2,4,5-Tetrazines and N-(Trimethylsilyl)benzaldimines

Masahiko Takahashi,* Yoshihiro Hikita, and Makoto Fukui

*Department of Materials Sciences, Faculty of Engineering, Ibaraki University, 4-12-1 Nakanarusawamachi, Hitachi, Ibaraki 316-8511, Japan

Abstract

Reation of 3,6-disubstituted 1,2,4,5-tetrazines (1) with N-(trimethylsilyl)benzaldimine gave 3,5,6-trisubstituted 2,5-dihydro-1,2,4-triazines (2), which were oxidized with potassium permanganate to afford 3,5,6-trisubstituted 1,2,4-triazines (6).

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1383-1390
Published online:
DOI: 10.3987/COM-89-5002
An Unusual Base-induces Debromination Reaction of 3,4-Dibromo-3-methoxycarbonylsulfolane

Ta-Shue Chou* and Lee-Jui Hwang

*Institutue of Chemistry, Academia Sinica, 128, Yan-Chiu-Yuan Road, Sec II, Nankang, Taipei,11529, Taiwan, R.O.C.

Abstract

Treatment of the title compoumd with several bases gives neither dehydrobromination nor substitution reaction. An unusual debromination reaction takes place to give 3-methoxycarbonyl-3-sulfolene.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1391-1397
Published online:
DOI: 10.3987/COM-89-5007
Enzymatic Cyclization of 2-(Carbamoyloxy)benzoates, 2-(Sulfamoyloxy)benzoates and 2-(Carbamoyloxy)benzophenones with Yeast and Lipase

Ahmed Kamal,* Maddamsetty V. Rao, Adari B. Rao, and Pralhad B. Sattur

*Division of Organic Chemistry, Regional Research Laboratory, Hyaderabad 500 007, India

Abstract

The cyclizatton of labile functionalized 2-(carbamoyloxy)-benzoates, 2-(sulfamoyloxy)benzoates and 2-(carbamoyloxy)benzophenones to 1,3-benzoxazine-2,4-diones, 4-oxo-3,4-dihydro-1,2,3-benzoxathiazine 2,2-dioxides and 4-phenyl-1,3-benzoxazin-2-ones with yeast as well as lipase is described. This approach establishes the application of enzymes for gram seale cyclization of such substrates under mild conditions. Further, it is revealed that baker’s yeast is most suitable for this process.

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Paper | Regular issue | Vol 29, No. 7, 1989, pp.1399-1408
Published online:
DOI: 10.3987/COM-89-5012
Pyridazines 47. The Configuration of Novel Thiosemicarboazone Derivatives of Pyridazinecarbaldehydes and Alkyl Pyridazinyl Ketones

Johnny Easmon, Gottfried Heinisch,* and Wolfgang Holzer*

*Institute of Pharmaceutical Chemistry, University of Vienna, Währinger Strasse 10, A-1090 Vienna, Austria

Abstract

Structure and configuration of thiosemicarbazone derivatives 1-6, containing a 3-pyridazinyl (1,2,3), 4-pyridazinyl (4,5) or 2-pyridyl moiety (6) were determined by means of 1H and 13C nmr spectroscopy.

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Review | Regular issue | Vol 29, No. 7, 1989, pp.1409-1429
Published online:
DOI: 10.3987/REV-89-408
Synthesis of Pyrimidine Derivatives and Their Related Compounds Using Ketene Dithioacetals

Yoshinori Tominaga,* Shinya Kohra, Harumasa Honkawa, and Akira Hosomi

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

Abstract

Ketene dithioacetals bearing electron-with-drawing groups are useful and versatile reagents for the synthesis of pyrimidine derivatives. This review article describes the synthetic usefulness and importance of ketene dithioacetals in the preparation of pyrimidines and fused pyrimidine derivatives.

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28 data found. 1 - 28 listed