Regular Issue

Vol. 26, No. 5, 1987

29 data found. 1 - 29 listed
Communication | Regular issue | Vol 26, No. 5, 1987, pp. 1161 - 1164
Published online:
DOI: 10.3987/R-1987-05-1161
A Novel C-C Coupling of Benzazoles Mediated by Dichlorocarbene — Formation of Bis-benzazoles

J. Shailaja Ro, Divi Sarangapani Iyengar, Uday Triambakraj Bhalerao, and S. Nagabhushan Rao

*Regional Research Laboratory, Hyderabad 500 007, Hyderabad 500 007

Abstract

The reaction of dichlorocarbene with benzazoles has led to the formation of bis-benzazoles. A reasonable mechanism has been proposed for this novel C-C coupling induced by dichlorocarbene.

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Communication | Regular issue | Vol 26, No. 5, 1987, pp. 1165 - 1167
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DOI: 10.3987/R-1987-05-1165
The Importance of Alcohol Nucleophilicity in the Trapping of the Photochemically Generated Radical Ion Pair from N-Methylphthalimide and α-Methylstyrene

Paul H. Mazzocchi, David Shook, and Leslie Liu

*Department of Chemsitry and Biochemistry, University of Maryland, College Park, MD 20742, U.S.A.

Abstract

The efficiency of alcohol trapping of the N-methylphthalimide-alkene radical ion pair has been shown to be a function of both solvent polarity and alcohol nucleophilicity.

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Communication | Regular issue | Vol 26, No. 5, 1987, pp. 1169 - 1172
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DOI: 10.3987/R-1987-05-1169
The Syntheses of (R)-(+)-β-Vanillyl-γ-butyrolactone and of Chiral Lignans Therefrom

Eric Brown and Alain Daugan

*Laboratorie de Synthèse, Faculté des Sciences, Route de Laval, BP 535, 72017 Le Mans Cedex, France

Abstract

(R)-(+)-β-vanillyl-γ-butyrolactone was obtained in 4 steps including a resolution, from vanillin and dimethyl succinate, and was used for the total syntheses of 5 naturally occurring and optically active lignans such as (+)-isolariciresinol 20.

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Communication | Regular issue | Vol 26, No. 5, 1987, pp. 1173 - 1176
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DOI: 10.3987/R-1987-05-1173
A Convenient Synthetic Approach to 4-Substituted Indoles

Fumio Yamada and Masanori Somei

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

Abstract

A simple and practical synthetic method for 4-halogenoindoles, 4-indolecarbaldehyde, 4-cyanoindole, and 4-methoxycarbonylindole is elaborated.

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Communication | Regular issue | Vol 26, No. 5, 1987, pp. 1177 - 1182
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DOI: 10.3987/R-1987-05-1177
Some Novel Observations on the Reaction of 1-Hydrazinophthalazine with Polycarbonyl Compounds

Hans Zimmer and Adel Amer

*Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, U.S.A.

Abstract

The reaction of 1-hydrazinophthalazine (1) with polycarbonyl compounds depends on the acid and acidity of the reaction as well as on the structure of the carbonyl components.

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Communication | Regular issue | Vol 26, No. 5, 1987, pp. 1183 - 1184
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DOI: 10.3987/R-1987-05-1183
On the Synthesis of N-Formyl-7-methyderhydronoraporphines

Nieves Atanes, Luis Castedo, Enrique Guitián, and José M. Saá

*Facultad de Química y Sección de Alcaloides, Deparamento de Química Orgánica, C. S. I. C., Santiago de Compostela, Spain

Abstract

lntermolecular benzyne cycloaddition (IBC) was used for the synthesis of the aporphinoid 1a, whose structure was corroborated by an independent photochemical route. Compound 1a Is not trichoguattine.

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Communication | Regular issue | Vol 26, No. 5, 1987, pp. 1185 - 1188
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DOI: 10.3987/R-1987-05-1185
Synthesis of Substituted 1,2,3,4-Tetrahydro-6-methyl-2-oxo-5-pyrimidinecarboxylic Acid Esters: The Biginelli Condensation Revisited

Brian C. O‘Reilly and Karnail S. Atwal

*Department of Chemistry, Isfahan University, Isfahan 81746-73441, Iran

Abstract

A general synthesis of substituted 1,2,3,4-tetrahydro-6-methyl-2-oxo-5- pyrimidinecarboxylic acid esters from 2-methylene-3-oxobutanoic acid esters and O-methylisourea hydrogen sulfate is reported.

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Communication | Regular issue | Vol 26, No. 5, 1987, pp. 1189 - 1192
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DOI: 10.3987/R-1987-05-1189
Synthesis of Substituted 1,2,3,4-Tetrahydro-6-methyl-2-thioxo-5-pyrimidinecarboxylic Acid Esters

Karnail S. Atwal, Brian C. O‘Reilly, Jack Z. Gougoutas, and Mary F. Malley

*Department of Chemistry, Isfahan University, Isfahan 81746-73441, Iran

Abstract

Substituted 1,2,3,4-tetrahydro-6-methyl-2-thioxo-5-pyrimidinccarboxylic acid esters are prepared in high overall yield from 2-methylene-3-oxobutanoic acid esters and 2-(4-methoxybenzyl)-2-thiopseudourea hydrochloride.

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Communication | Regular issue | Vol 26, No. 5, 1987, pp. 1193 - 1196
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DOI: 10.3987/R-1987-05-1193
A Synthesis of a Spirocyclopropane-1,1‘-carbapenem

Choung Un Kim, Peter F. Misco, and Bing Y. Luh

*Bristol-Myers Squibb Phramaceutical Research Institute, Wallingford, Connecticut 06492-7660, U.S.A.

Abstract

The total synthesis of the spirocyclopropanel, 1’- carbapenem 13 has been achieved through the Wittig cyclization of the phosphorane 11. A modified Simmons-Smith reaction on the olefinic ketone 6 gave the key cyclopropane derivative 7 in good yield.

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Communication | Regular issue | Vol 26, No. 5, 1987, pp. 1197 - 1202
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DOI: 10.3987/R-1987-05-1197
A Short Step Synthesis of Clavicipitic Acids from 4-Cyanomethylindole

Masakatsu Matsumoto, Hisako Kobayashi, and Nobuko Watanabe

*Sagami Central Research Center, 4-4-1 Nishi-Ohnuma, Sagamihara, Kanagawa 229-0012, Japan

Abstract

4-(3-methyl-1-oxo-2-buten-1-y1)indole (3) was efficiently synthesized from 4-cyanomethyl-l-(p-toluenesulfonyl)indole by alkylation with 2-methyl-2-buten-1-yl tosylate and by successive aerobic oxidation and deprotection of N-tosyl group. The acylindole 3 was used for a short step synthesis of clavicipitic acids (4).

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Communication | Regular issue | Vol 26, No. 5, 1987, pp. 1203 - 1206
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DOI: 10.3987/R-1987-05-1203
Stereoselective Alkylation of Ester Lactone. Synthesis of dl-Geijerone and Formal Synthesis of dl-γ-Elemene

Takeshi Wakamatsu, Hiromu Hara, Keiko Taira, and Yoshio Ban

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

Abstract

Geijerone 1 was synthesized in racemic form via stereoselective alkylation of an ester lactone conformationally fixed with its bridged lactone ring. dl-γ-Elemene 2 has already been obtained from 1.

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Communication | Regular issue | Vol 26, No. 5, 1987, pp. 1207 - 1210
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DOI: 10.3987/R-1987-05-1207
Synthetic Studies on Mitomycin I. Synthesis of 7-Methoxymitosene from 6-Methylindole by Selective Oxidation of Benzene Part

Osamu Asano, Shin-ichi Nakatsuka, and Toshio Goto

*Laboratory of Organic Chemistry, Faculty of Agricultures, Nagoya University, Chikusa, Nagoya, Aichi 464-8601, Japan

Abstract

Synthesis of 7-methoxymitosene 3, one of the mitosene analog containing common carbon skeleton in mitomycin series was achieved in 19 steps from 6-methylindole 4 by oxidative functionalization methods.

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Communication | Regular issue | Vol 26, No. 5, 1987, pp. 1211 - 1214
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DOI: 10.3987/R-1987-05-1211
Structure of Pelirine and Chemical Conversion of Gardnerine to 11-Methoxy-16-epiaffinine

Alfred S. C. Wan, Masaki Yokota, Koreharu Ogata, Norio Aimi, and Shin-ichiro Sakai

*Faculty of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan

Abstract

The Structure of pelirine, isolated from roots of Rauwolfia perakensis was shown to be 10-methoxyepiaffinine by comparison with the spectral data of 11 -methoxyepiaffinine which was synthesized from the known alkaloid gardnerine. The proposed structure has been confirmed by X-ray crystallography.

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Communication | Regular issue | Vol 26, No. 5, 1987, pp. 1215 - 1220
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DOI: 10.3987/R-1987-05-1215
Facile Synthesis and Herbicidal Activities of Novel Fluoroquinoxalines

Kenji Makino and Hirosuke Yoshioka

*The Institute of Physical and Chemical Research, Wako-shi, Saitama 351-0198, Japan

Abstract

The synthesis of new 2-fluoro-, 3-fluoro- and 2,3-difluoroquinoxalines by nucleophilic substitution with cesium fluoride as coupled with 18-crown-6 and their herbicidal activities are described.

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Paper | Regular issue | Vol 26, No. 5, 1987, pp. 1221 - 1226
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DOI: 10.3987/R-1987-05-1221
Metal Reagents in Organic Reactions: Part V — Reactions of Coumarins with Thallium (III) Salts

Avijit Banerji and Gopa Nandi

*Chemistry Department, University College of Science, 92 Acharya Prafulla Chandra Road, Calcutta-700009, India

Abstract

The reactions of several coumarins with thallium (III) salts have been investigated. The compounds isolated were usually oxidation products derived from initially formed organometallics.

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Paper | Regular issue | Vol 26, No. 5, 1987, pp. 1227 - 1238
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DOI: 10.3987/R-1987-05-1227
The Synthesis of Two Strongly Electron Deficient Flavin Analogs

Czeslaw Radziejewski, Soumitra Ghosh, and Emil Thomas Kaiser

*Laboratory of Bioorganic, Chemistry Department, Rockefeller University, 1230 York Avenue, New York, NY 10021, U.S.A.

Abstract

The synthesis of 7-chloro-8-acetyl-10-methylisoalloxazine (2a) and 7-cyano-8-acety1-10-merhylisoalloxazine (2b) was accomplished by the condensation of appropriately substituted o-diamines with alloxan under acidic conditions. The presence of the strongly electron withdrawing chlorine and cyano substituents makes these flavin analogs very effective catalysts of the oxidation of N-alkyl-1,4-dihydronicotinamides. Compound 2a was also found to undergo redox reactions with substrates readily forming carbanions (e.g., nitroethane).

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Paper | Regular issue | Vol 26, No. 5, 1987, pp. 1239 - 1249
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DOI: 10.3987/R-1987-05-1239
Synthesis of (±)-Praeruptorin A and Related Khellactone Derivatives

Swati Bal-Tembe, Dilip N. Bhedi, Noel J. de Souza, and Richard Helmut Rupp

*Department of Chemistry, Research Centre, Hoechst India Limited, Mulund, Bombay 400 080, India

Abstract

The first synthesis of the pyranocoumarin natural product, (±)-praeruptorin A (= Pd-Ia), is described. A general method for the preparation of various khellactone derivatives is reported.

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Paper | Regular issue | Vol 26, No. 5, 1987, pp. 1251 - 1255
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DOI: 10.3987/R-1987-05-1251
Jamtine-N-oxide — A New Isoquinoline Alkaloid from Cocculus hirsutus

Viqar Uddin Ahmad, Atta-ur-Rahman, Tahir Rasheed, and Habib-ur-Rehman

*H. E. J. Postgraduate Institute of Chemistry, University of Karachi, Karachi-75270, Pakistan

Abstract

A new isoquinoline alkaloid, jamtine-N-oxide has been isolated from Cocculus hirsutus. Its structure has been assigned as C20H25NO5 (1) on the basis of pectral studies. Its stereochemistry has been determined by homonuclear 2D 1H-NMR (COSY-45, J-resolved, NOESY) and 13C-NMR assignments made by GASPE experiments.

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Paper | Regular issue | Vol 26, No. 5, 1987, pp. 1257 - 1262
Published online:
DOI: 10.3987/R-1987-05-1257
Addition of Phthalimidonitrene to Substituted Indoles

Perumal Raja Kumar

*Department of Chemistry, University of Madras, Madras 600 025, India

Abstract

The aziridine 2a obtained by the addition of phthalimidonitrene to N-phenylsulphonylindole was treated with methanolic potassium hydroxide to give desulphonated indole and quinazoline. The aziridine 2b and 2c derived from phthalimidonitrene and 2-methylindole or 2-phenylindole were treated with dimsyl anion to give 2-methylquinazoline and 2-phenylquinazoline. However the nitrene adducts 2d and 2e derived from 1,2,3,4-tetrahydrocarbazole and 1-oxo-1,2,3,4-tetrahydrocarbazole afford carbazole and 1-hydroxycarbazole under similar conditions. Hydrazinolysis of the nitrene adducts-2a, b, c, d and e regenerated the parent indole.

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Paper | Regular issue | Vol 26, No. 5, 1987, pp. 1263 - 1270
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DOI: 10.3987/R-1987-05-1263
Reinvestigation of the Reaction of Nicotinic Acid 1-Oxide with Acetic Anhydride

Hiroyuki Nagano, Masatomo Hamana, Yoshiharu Nawata, Supaluk Prachayasittikul, Ashraf N. Abdel-Sayed, and Ludwing Bayer

*Central Research Laboratories, Chugai Pharmaceutical Company, Ltd., Takada 3-41-8, Toshima-ku, Tokyo 171, Japan

Abstract

Reinvestigation of the reaction of nicotinic acid 1-oxide (1) with boiling acetic anhydride has revealed that the primary product is not 2-acetylnicotinic acid 1-oxide (3) but 3- acetoxy-4-aza-3-methyl-1(3H)-isobenzofuranone 4-oxide (2), the acetate of the ring tautomer of 3. Reactions of 2 and 3 with phosphorus trichloride and some related reactions are reported.

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Paper | Regular issue | Vol 26, No. 5, 1987, pp. 1271 - 1275
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DOI: 10.3987/R-1987-05-1271
Reactions of (-)-Physositigmine and (-)-N-Methyphysostigmine in Refluxing Butanol and at High Temperature: Facile Preparation of (-)-Eseroline

Qian-Sheng Yu, Bernhard Schönenberger, and Arnold Brossi

*Section of Medical Chemistry, Laboratory of Analytical Chemistry, NIDDK, National Institute of Health, Bethesda, MD 20982, U.S.A.

Abstract

(-)-Physostigmine (1), when refluxed in 1-butanol in the presence of sodium butylate afforded (-)-eseroline (3) in high yield, isolated as fumarate salt. Butyl N-methylearbamate (4) was obtained from the mother liquor. (-)-N-Methylphysostigmine (2), prepared from 3 and dimethylearbamoyl chloride, underwent under these conditions, similar decomposition suggesting that formation of 3 from 1 and 2 is the result of a nucleophilic substitution. Subliming, or distilling 1, in high vacuum afforded (-)-eseroline (2) and methyl isocyanate trapped by 1-butanol as butyl N-methylcarbamate (4). Compound 3distilled without decomposition. It is suggested that pyrolysis of 1, therefore, proceeds by fragmentation, forming N-methylisocyanate and (-)-eseroline (3) as reaction products.

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Paper | Regular issue | Vol 26, No. 5, 1987, pp. 1277 - 1282
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DOI: 10.3987/R-1987-05-1277
Pyrazoles Derived from Dihydralazine

Adel Amer, Nagwa Rashaed, Mohamed M. Abdel Rahman, and Hans Zimmer

*Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, U.S.A.

Abstract

The syntheses of some bis-(3,5-disubstituted pyrazolyl)phthalazines derived from dihydralazine (1) are described. Their structure assignments are bared on 1H-, and 13C-nmr spectroscopic data ar well as results of elemental analyses.

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Paper | Regular issue | Vol 26, No. 5, 1987, pp. 1283 - 1289
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DOI: 10.3987/R-1987-05-1283
On the Configuration and the Conformation of 2-Acylindazole Arylhydrazones

Giuseppe Cusmano, Gabriella Macaluso, Werner Hinz, and Silvestre Buscemi

*Instituto de Chimica Organica, Facolta de Scienze, Università digli Studi di Palermo, 20 via Archirafi, 90123 Palermo, Italy

Abstract

The Z configuration of 2-acylindazole arylhydrazones 3 was assigned on the basis of solvent effects on their 1H-nmr spectra. Due to free rotation around the N-C bond, the title compounds exist in a solvent dependent equilibrium between the intramolecular N-H bonded conformer 6 and its rotamers.

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Paper | Regular issue | Vol 26, No. 5, 1987, pp. 1291 - 1302
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DOI: 10.3987/R-1987-05-1291
Synthesis and Determination of the Absolute Stereochemistry of the Enantiomers of 3-Substituted 1,2,3,4-Tetrahydroisoquinolines Related to the Calcium Antagonist Verapamil

Robin D. Clark, Jacob Berger, Chi-Ho Lee, and Joseph M. Muchowski

*Institute of Organic Chemistry, Syntex Discovery Research, 3401 Hillview Avenue, Palo Alto, California 94304, U.S.A.

Abstract

The four stereoisomers of 3-[4-cyano-4-(3,4-dimethoxypheny1)- 5-methylhex-l-yl]-1,2,3,4-tetrahydro-6,7dimethoxy-2-methylisoquinoline (2) were prepared. The stereochemistry of the side chain quaternary carbon was derived from iodide 4 of known absolute configuration. The absolute stereochemistry at the 3-position of the tetrahydroisoquinoline was determined by correlation with L-DOPA. These compounds are related to the calcium antagonist verapamil and the calcium antagonist activity was greatest for the (3S,4S) isomer.

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Paper | Regular issue | Vol 26, No. 5, 1987, pp. 1303 - 1312
Published online:
DOI: 10.3987/R-1987-05-1303
Methyl N-Aryldithiocarbamates: Useful Reagents for the Annelation of Pyrimidines and 1,3-Oxazines to Five-membered Heterocuclic Rings

Javier Garín, María Pilar Loscertales, Enrique Meléndez, Francisco L. Merchán, Ricardo Rodriguez, and Tomás Tejero

*Department of Organic Chemistry, Instituto de Ciencias de Materiales de Aragón, University of Zaragoza, 50009-Zaragoza, Spain

Abstract

The reaction of methyl N-aryldithiocarbamates with π-excessive heteroaromatic o-amino acid derivatives leads to the annelation of 4-oxo-2-thioxopyrimidines, 2,4-dioxopyrimidines or 2-arylamino-1,3-oxazines, depending on the reaction conditions.

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Paper | Regular issue | Vol 26, No. 5, 1987, pp. 1313 - 1322
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DOI: 10.3987/R-1987-05-1313
Photochemical and Thermal Reactions of Heterocycles. IV. Phooto-oxidation Reactions of Mesoionic Dithioliumolate, Thiazoliumolate, and Related Heterocycles. Solvent Effects of the Course of the Photo-oxidation

Hiroshi Kato, Kazue Tani, Haruki Kurumisawa, and Yoshiko Tamura

*Department of Chemistry, Faculty of Science, Shinshu University, Asahi, Matsumoto 390-8621, Japan

Abstract

Photo-oxidation of mesoionic 1,3-dithiolium-4-olates (1) gave diacyl disulfide (2), and that of a mesoionic thiazolium-4-olate (6) and oxazolium-5-olate (9) gave diacylamides as the main products. The formation of these products was rationalized by a route involving fragmentation of the corresponding endoperoxides, which are formed by cycloaddition of singlet oxygen on the mesoionic rings. Photo-oxidation of 5(4H)-oxazolones (12) and a 5(4H)-thiazolone (17) in dichloromethane gave the corresponding dehydro-dimers, while that of the former in dimethylformamide gave mainly diacylamides. The acylamides were considered to arise via the endoperoxides of the mesoionic tautomers.

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Paper | Regular issue | Vol 26, No. 5, 1987, pp. 1323 - 1332
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DOI: 10.3987/R-1987-05-1323
Fused Thiazoles from 3-Amino-thiazoline-2-thiones: Synthesis of Pyrazolo[5,1-b]thiazole and Thiazolo[2,3-b]-1,3,4-thiadiazine Derivatives

Pedro Molina, Antonio Arques, Maria de los Desamparados Velasco, and José Manuel Villalgordo

*Departmento de Química Orgánica, Facultad de Ciencias, Universidad de Murcia, 30071 Murcia, Spain

Abstract

Two approaches for the preparation of a number of pyrazolo[5,1-b]-blthiazoles are reported. The first involves reaction of 3-amino-4-phenyl-thiazoline-2 -thione 1 with phenacyl bromides to give thiazolo[2,3-b]-1,3,4-thiadiazines 2 which by action of triethylamine are converted into the pyrazolo[5,1-b]thiazoles 4. The second is based on the reaction of 3-amino-2-methylthio-4-phenylthiazolium cation 5 with activated acetonitriles to give 7-substituted 6-amino-3-phenylpyrazolo[ 5,1-b]thiazoles 7.

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Review | Regular issue | Vol 26, No. 5, 1987, pp. 1333 - 1344
Published online:
DOI: 10.3987/R-1987-05-1333
The N-Carboxylic Acids of Nitrogen Heterocycles

Alan R. Katritzky, Hassan Faid-Allah, and Charles M. Marson

*Center for Drug Discovery, College of Pharmacy, University of Florida, Gainesville, Florida 32611-7200, U.S.A.

Abstract

Nitrogenous heterocyclic carbamic acids posseas considerable stability and can frequently be isolated as free acids. A variety of synthetic methods are available and the expected range of derivatives is formed. Recently, such N-carboxylic acids have been demonstrated to form useful protecting/activating groups in metalation reactions.

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Review | Regular issue | Vol 26, No. 5, 1987, pp. 1345 - 1382
Published online:
DOI: 10.3987/R-1987-05-1345
Stereospecific Deoxygenation of Epoxides to Olefins

Henry N. C. Wong, Charles C. M. Fok, and Timothy Wong

*Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, Hong Kong

Abstract

Various methods for stereospecific deoxygenation of epoxides to olefins are presented. The mechanisms involved in these transformations will also be discussed.

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29 data found. 1 - 29 listed