HETEROCYCLES
An International Journal for Reviews and Communications in Heterocyclic ChemistryWeb Edition ISSN: 1881-0942
Published online by The Japan Institute of Heterocyclic Chemistry
Regular Issue
Vol. 26, No. 2, 1987
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■ Heteroaromatic Azo-activated Nucleophilic Substitutions. The Reaction of 4-(p-Methoxyphenylazo)pyridinium Methiodide with Piperidine in Dimethyl Sulphoxide
Ikenna Onyido and Collins I. Ubochi
*Department of Chemistry, University of Ibadan, Ibadan, Nigeria
Abstract
The azopyridinium-activated phenyl methyl ether, 1, undergoes nucleophilic attack by piperidine in dimethyl sulphoxide predominantly at the aryl carbon centre in a reaction that is base catalyzed and faster than the corresponding reaction of the dinitro-activated analogue, 2, by more than two decades.
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■ Claisen Rearrangement of 5- or 7-Propargyloxyflavones: Formation of Pyranoflavones
Kode Nagesware Rao and Gotety Srimannarayana
*Department of Chemistry, Osmania University, Hyderabad 500 007, India
Abstract
The Claisen rearrangement of 7-propargyloxy-5-hydroxy-3-phenylflavone, 7-propargyloxy-5-hydroxy-3-methylflavone and 7-methoxy-5-propargyloxy- 3-methylflavone in N,N-dimethylaniline at 195°C resulted in the formation of angular 2H-[1]-pyranoflavones, 2,3-diphenyl-5-hydroxy-8H-4-oxobenzo-[1,2-b:5,6-b’]dipyran, 5-hydroxy-3-methyl-2-phenyl- 8H-4-oxobenzo-[1,2-b:5,6-b’]dipyran and 9-methoxy-3-methyl- 2-phenyl-6H-4-oxobeno-[1,2-b:3,4-b’]dipyran, respectively in 50% yields. The structures were determined by spectral characteristics.
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■ [4+2]-Cycloaddition to 4-Demethoxycarbazomycin
Ulf Pindur and Ludwig Pfeuffer
*Department of Chemistry and Pharmacy, Institute of Pharmacy, University of Mainz, Saarstrasse 21, D-55122 Mainz, Germany
Abstract
The first synthesis of 4-demethoxycarbazomycin is described; the key step is the cycloaddition using a 3-vinylindole equivalent and dimethyl acetylenedicarboxylate as the dienophile.
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■ Thermolysis of Phenoxyacetyl-cyanomethylenetriphenylphosphoranes — Tandem Intramolecular Witting and Claisen Rearrangement Reactions
Rambabu Yadla and Jampani Madhusudana Rao
*Regional Research Laboratory, Hyderabad 500 007, India
Abstract
Thermolysis of acyl-cyanomethylenetriphenylphosphorane containing aryloxyacetyl moiety in the acyl group results in tandem intramolecular Wittig and Claisen rearrangement reaction. The orthoallenylphenol intermediates formed cyclise to give a 2H-chromene or a benzofuran depending on substituents.
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■ Solid State Behaviour of "Dynamic Compounds": A 13C CP/MAS NMR Spectroscopy Study
Robert Faure, Emile-Jean Vincent, André Rousseau, and José Elguero
*Instituto de Química Médica, C. S. I. C., Calle Juan de Cierva, 3, 28006 Madrid, Spain
Abstract
The 13C CP/MAS NMR spectra of 2-methylimidazole, antipyrine, 1-phenyl-3-hydroxy-5-methylpyrazole, 1-p-bromophenyl-3-methyl-pyrazolin-5-one, tetrazolo[5,1-b]benzothiazole,and 9-acetylcarbazole have been recorded and the signals assigned. Problems such as annular prototropic tautomerism, functional tautomerism, azido/tetrazole isomerism, and rotational isomerism have been studied and, in most cases, solved.
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■ A Novel Synthesis of Pyridazines: Inverse Electron Demand Diels-Alder Reaction of Tetrazines with Acyclic Dienamines
Dipak Ranjan Borthakur, Dipak Prajapati, and Jagir Singh Sandhu
*Division of Drug and Pharmaceutical Chemistry, Regional Research Laboratory, Jorhat 785 006, Assam, India
Abstract
Tetrazines (1) when reacted with dienamines (2) furnished, pyridazines (3) and (4) in good yields. This appears to be the first case wherein the intermediate bipyridazinea (8) have fragmented to (3) and (4) prefering rupture of carbon-carbon bond.
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■ Chiral Pool Synthesis of 8-Hydroxymethyl-"9-oxa"-anthracyclinones
Hanh Dufat-Trinh Van, François Tillequin, Claude Monneret, and Michel Koch
*Depattement fr Pharmacognosie associé au CNRS, UA n°484, Faculté de Pharmacie, 4 avenue de l’Observatoire, 75270 Paris Cedex 06, France
Abstract
The synthesis of title compounds from (R)-2,3-0-isoprapylidene glyceraldehyde and leucoquinizarin is reported.
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■ Organogermanium Compounds: Synthesis, Structure, and Properties of Masked-carboxyethylgermanium Sesquioxide (GE-132) and Related Compounds with One Triethanolamine Component
Norihiko Kakimoto, Katsuyuki Sato, Toyozo Takada, and Mitsuo Akiba
*School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
Abstract
The synthesis, structure, and properties of maskedcarboxyethylgermanium sesquioxide (Ge-132) and related compounds with one triethanolamine component were investigated. The hydrolysis of these compounds afforded triethanolamine and trihydroxygermylpropanoic acid derivatives which are important for their biological activity .
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■ Palladium Catalyzed Coupling of 5-Hydroxyuracil Trifluoromethanesulfonates (Triflates) with Alkenes and Alkynes
Kosaku Hirota, Yukio Kitade, Yoshiaki Isobe, and Yoshifumi Maki
*Labolatory of Medicinal Chemistry, Gifu Pharmaceutical University, 6-1 Mitahora-higashi 5-chome, Gifu 502-8585, Japan
Abstract
Cross coupling of 5-hydroxyuracil triflates (1) with alkenes and alkynes in the presence of a palladium catalyst and triphenylphosphine affords 5-vinyluracils (2) and 5-alkynyluracils (3), respectively, in good yields. Coupling of the triflate (1a) with organocopper reagents [R2Cu(CN)Li2] is also described.
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■ A Regio and Diastereoselective Bromolactamization of δ,γ-Unsaturaterd Thioimidates
Shinzo Kano, Tsutomu Yokomatsu, Haruo Iwasawa, and Shiroshi Shibuya
*School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
Abstract
Cyclization of N-substituted E-δ,γ-unsaturated thioimidates (5a-f) with bis(collidine)bromonium perchlorate, followed by treatment with aqueous sodium carbonate afforded the corresponding N-substituted threo-2- (2’-bromoalky1)pyrrolidin-5-ones (10a-f), respectively, with high diastereoselectivity. Cyclization of Z-unsaturated thioimidate (9) gave the erythro isomer (12).
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■ Synthesis of 1,2-Benzoquinones from 1,4-Benzodioxins Using the Reaction with Ozone Followed by Photolysis
Choji Kashima, Atsushi Tomotake, and Yoshimori Omote
*Department of Chemistry, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba-shi, Ibaraki, 305-8571, Japan
Abstract
Ozonolysis followed by photolysis of 1,4-benzodioxins (1) was carried out, and 1,2-benzoquinones (3) and catechols (4) were obtained as products. It was noteworthy that labile 4-chloro-1,2-benzoquinone (3b) was obtained in a moderate yield as much as that of stable 4-tert-1,2-benzoquinone (3c). Mechanistic study was also discussed.
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■ Strained Heterocyclic Systems. 13. Dipole Moments of Cycloalka[b]quinolines
J. Hodge Markgraf, James F. Skinner, John M. Ellison, and G. Thomas Marshall
*Department of Chemistry, Williams College, 47 Lab Campus Drive, Williamstown, MA 01267, U.S.A.
Abstract
The electric dipole moments of 2,3-dimelhylnaphthalene (1), 2,3-dimethylquinoline (2), 2,3-dihydro-1H-cyclopenta[b]qulnoline (3), and 1,2-dihydrocyclobuta[b]quinoline (4) have been determined experimentally. The measured values in benzene are 0.72, 2.04, 2.13, and 2.17 D, respectively. Ring strain effects thus do not significantly alter dipole moments.
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■ Diastereoselective Synthesis of trans-4,5-Disubstituted Oxazolidin-2-ones and Vicinal Amino Alcohols through Alkylation of N-Acyliminium Ion Intermediates
Shinzo Kano, Yoko Yuasa, and Shiroshi Shibuya
*School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
Abstract
Treatment of 5-substituted 4-ethoxyoxazolidin-2-ones (10a-f, 13a,b) with allyltrimethylsilane in the presence of titanium tetrachloride gave the corresponding trans-4,5-disubstituted oxazolidin-2-ones (14a-f, 16a,b), respectively, with high diastereoselectivity. Methallylation of 13a,b with methallyltrimethylsilane yielded 16c,d, respectively. Ring cleavage of 14a-f afforded the corresponding three vicinal amino alcohols (17a-f), respectively.
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■ Use of the Pummerer Reaction in the Synthesis of Eburna and Aspidosperma Deribvatives
Denis Génin, R. Zo Andriamialisoa, Nicole Langlois, and Yves Langlois
*Institut des Chimie des Substances Naturelles, C.N.R.S., 1 avenue de la Terrasse, Bat. 27, 91198 Gif-sur-Yvette Cedex, France
Abstract
The Pummerer reaction applied to indoloquinolizidine derivatives (7) led to compounds (9), (10) and (12) which are precursors of Eburna and Aspidosperma derivatives.
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■ Cyclization of Thiophenedicarboxaldehyde with Nitromethane
Mohamed El Borai and Mahmoud Fahmy
*Department of Chemistry, Faculty of Science, Tanta University, Tanta 31527, Egypt
Abstract
The reaction of thiopheno [3,4-c]and[2,3-b]dicarbaxaldehyde with nitramethane in alcoholic potassium hydroxide afforded the corresponding 5-nitro-4Hcyclopenta [c]thiophen-4-ol II and 5-nitro-4H-cyclopenta[b]thiophen-4-ol III, respectively.
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■ The Use of 13C N.M.R. in the Determination of Stereochemistry of 1,2,3-Trisubstituted Tetrahydro-β-carbolines
Patrick D. Bailey and Sean P. Hollinshead
*Department of Chemistry, University of York, Heslington, York YO1 5DD, U.K.
Abstract
The chemical shift of the benzylic carbon of N (2)-benzyl-cis-1,3-disubstituted 1,2,3,4-tetrahydro-β-carbolines is downfield of the corresponding peak of the trans-isomer, and should be valuable, therefore, in the assignment of stereochemistry to these systems.
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■ The Reaction of 1-Methyl-2-vinylindoles with 4-Phenyl-1,2,4-triazoline-3,5-dione
Rosa Teresa Sanchis-Llorca, José Sepúlveda-Arques, Elena Zaballos-Garcia, and R. Alan Jones
*Departamento de Química Orgánica, Facultad de Farmacia, Universidad de Valencia, Calle Dr. Moliner, 50, E-46100 Burjassot (Valencia), Spain
Abstract
1-Methyl-2-vinylindoles (1⇔2) react readily with 4-phenyl-1,2,4-triazoline-3,5-dione at 20°C to yield the Michael-type 1:1 adducts (3). No evidence was found for the formation of any cycloadducts.
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■ Isolation and Structural Studies on the Alkaloids of Rhazya stricta
Atta-ur-Rahman and Sajida Khanum
*H. E. J. Postgraduate Institute of Chemistry, University of Karachi, Karachi-75270, Pakistan
Abstract
A new alkaloid isorhazicine (2) has been lsolated from the leaves of Rhazya strica The structure and relative stereochemistry have been determined by spectroscopic studies, particularly by NOE difference. COSY-45° and DEPT experiments. Isorhazicine (2) was shown to differ from rhazicine (1) in that it bearss ‘Z’ configuration of the ethylidene group.
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■ Isolation of 19,20-Z-Vallesamine and 19,20-E-Vallesamine from Alstonia scholaris
Atta-ur-Rahman, Khisal Ahmad Alvi, Syed Ali Abbas, and Wolfgang Voelter
*H. E. J. Postgraduate Institute of Chemistry, University of Karachi, Karachi-75270, Pakistan
Abstract
A new alkaloid 19,20-Z-Vallesamine along with 19,20-E-vallesamine has been isolated from the leaves of Alstonia scholaris and the stereochemistry has been deduced from NOE measurements.
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■ Direct Access to 4-Substituted 3-Isochromanones by the pH Controlled Addition of Aldehydes
Michel Barbier
*Institut des Chimie des Substances Naturelles, C.N.R.S., 1 avenue de la Terrasse, Bat. 27, 91198 Gif-sur-Yvette Cedex, France
Abstract
Aldehydes condense at position 4 of 3-isochromanone in the presence of a base, in competition with the ring opening of the lactone. By control of the pH, the new syn and anti 4-ethyliaene and benzylidene derivatives are obtained with yields of 30 and 28%. Due to the strong interaction of the olefinic proton with the carbonyl group of the lactone, in particular in the case of the stilbene structures prepared through reaction with a benzaldehyde, these syn and anti isomers are easily resolved by chromatography and characterized. The 4-methylene 3-isochromanone obtained through addition of formaldehyde is not stable and polymerizes readily to a mixture of polymers.
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■ Ortho-lithiation of 2-(Benzothiazol-2-ylthio)pyridine. Preparation of 2,3-Disubstituted Pyridines
Alan R. Katritzky,* Jose M. Ayrrecoechea, and Luis M. Vazquez de Miguel
*Center for Drug Discovery, College of Pharmacy, University of Florida, Gainesville, Florida 32611-7200, U.S.A.
Abstract
2-(Benzothiazal-2-ylthio)py1idine undergoes lithiation exclusively at the 3-position. The products of reaction with electrophiles of the lithiated species undergo sulfide cleavage to give 3-substituted 2-alkylthiopyridines and/or 3-substituted pyridine-2-thiones.
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■ Acetoxylation of 1-Benzyloxy β-Lactams at C-4 via a Reduction-oxidation Sequence
Paulus A. van Elburg and David N. Reinhoudt
*Laboratory of Organic Chemistry, Twente University of Technology, Enschede, The Netherlands
Abstract
Selective dihydroalane reduction of 1-benzyloxy β-lactams 4 affords 1-(benzy1oxy)azetidines 6 which can be debenzylated to give the 1-hydroxy azetidines 7. Oxidation of the compounds 7 either gives a mixture of β-lactams 10 and 11 or selectively β-lactams 10.
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■ Alkaloids of Hedycarya angustifolia
Y. A. Geewanda P. Gunawardana, Huck-Meng Leow, and I. Ralph C. Bick
*Department of Chemistry, University of Tasmania, GPO Box 252C Hobart, Tasmania, 7001, Australia
Abstract
Four new alkaloids, 6,6a-dehydronorlaureline (7), isosevanine (10), isouvariopsine (12), and O-methylcinnamolaurine (14) have been isolated from H. angustifolia, and their structures have teen determined. The plant also contains the known apophines corydine (1), laurotetanine (2), boldine (3), qlaucine (4), and laureline (5).
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■ Some Nucleophilic Substitutions in the 2,4-Dimethoxypyrido[3,2-d]pyrimidines
Hassan M. Eisa, Said M. Bayomi,* Abdel-Kader M. Ismaiel, and Mohamed M. El-Kerdawy
*Department of Medical Chemistry, Faculty of Pharmacy, University of Mansoura, Mansoura, Egypt
Abstract
Study of the reactivity of substituted pyrido[3,2-d]-pyrimidines (Ia,b), towards nucleophilic substitution reactions revealed that the methoxy substituents at 4- as well as of the ester moiety at 6-positions are readily susceptable to nucleophilic displacement. The observed selectivity enabled the preparation of 4-hydrazino-6-acid hydrazides (IIa,b). Confirmation for formation of (IIa,b) has been done by their reaction with different carbonyl compounds to give the respective hydrazones (IIIa-i) or by reactlon with nitrous acid to afford the corresponding 4-azido-6-acid azides, which underwent ring closure with the formation of tetrazole ring derivatives (IVa,b). The synthesized compounds were confirmed by elemental analyses, 1H NMR and mass spectral data.
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■ Ajmalinimine — A New Alkaloid from Rauwolfia serpentina Benth
Salimuzzaman Siddiqui,* S. Imtiaz Haider, and S. Salman Ahmad
*H. E. J. Postgraduate Institute of Chemistry, University of Karachi, Karachi-75270, Pakistan
Abstract
A new dihydroindole alkaloid ajmalinimine has been isolated from the roots of Rauwolfia serpentina Benth.collected from Thailand. Its structure was determined as 10-C,17-O-diacetylajmaline on the basis of chemical and spectroscopic studies.
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■ Novel Substituted Adamantane-spiro-5-oxazolidine Derivatives
Vassil St. Georgiev,* Christpher G. Acker, and C. Richard Kinsolving
*Department of Organic Chemistry, Pharmaceutical Division, Pennwalt Corporation, Rochester, New York 14623, U.S.A.
Abstract
The synthesis of a series of subetituted admantane-spiro-5-oxazolidin-2-one (3-6) and adamantane-spiro-5-oxazolidine (7-10) derivatives, is described. Compounds 7-10 represent novel adamantane-spiro-heterocyclic systems.
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■ Studies of Fungal Products. XII. Structure of Aurantioemestrin from Emericella striata
Ken-ichi Kawai,* Koohei Nozawa, Hideyuki Seya, Nobuo Kawahara, Shun-ichi Udagawa, and Shoichi Nakajima
*Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
Abstract
The structure of aurantioemestrin (1), a new degradated dioxopiperazine isolated from Emericella striata (80-NE-22), was established as 1 on the basis of spectroscopic evidences. Aurantioemestrin (1), a dioxopiperazinethione, seems to be the biogenetical key intermediate from emestrin (3) to dethiosecoemestrin (2).
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■ Advances in the Synthesis of Substituted Pyridazines via Introduction of Carbon Functional Group into the Parent heterocycle
Gottfried Heinisch
*Institute of Pharmaceutical Chemistry, University of Vienna, Währinger Strasse 10, A-1090 Vienna, Austria
Abstract
Methods for the convenient synthesis of various simple pyridazine derivatives based on Minisci-type reactions are reviewed. Due to the pronounced regioselectivity of radicalic attack at C-4 and/or C-5 of the protonated 1,2-diazine system homolytic substitution reactions with nucleophilic carboncentered radicals permit an experimentally easy access to pyridazinecarbaldehydes and C-alkyl or C-alkoxycarbonyl derivatives thereof (via trioxanylpyridazines), alkyl and aryl pyridazinylketones (via acyl- or aroylpyridazinecarboxylic acids), pyridazinedicarboxylic acid esters, C-alkylpyridazine monocarboxylic acid esters and α-N-amidoalkylpyridazines. The reactivity and the synthetic utility of these classes of compounds are discussed briefly. In addition, syntheses of 3-pyridazinecarbonitrile and 4- or 6- alkyl derivatives thereof are described. These compounds are readily obtained via N-arylsulfonyl Reissert compounds.
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■ The Synthetic Potentialities of Nitriles in Heterocyclic Synthesis
Mohamed Hilmy Elnagdi, Sherif Mourad Sherif,* and Rafat Milad Mohareb
*Department of Chemistry, Faculty of Science, University of Cairo, Giza, Egypt
Abstract
The synthetic potentialities of nittiles as synthons for a variety of heterocycles are surveyed.