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. 53, No. 5, 2000
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■ A New Approach for Construction of Quarternary Chiral Centers: Preparation of α-Branched Serine Derivatives
Hidemitsu Uno,* Ken-ichi Kasahara, and Noboru Ono
*Advanced Instrumentation Center for Chemical Analysis, Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan
Abstract
In the presence of a Lewis acid, the Michael-type reaction of (3R)-5-tert-butyldimethylsiloxy-3-phenyl-1H-pyrrolo[1,2-c]oxazole (1) with nitro olefins smoothly occurred to give 7a-alkylated pyrrolo[1,2-c]oxazol-5-ones (2) in good yields. The products (2) were successfully transformed to a α-branched serine derivatives via reductive denitration followed by lactam-ring cleavage.
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■ The First Total Synthesis of Bufobutanoic Acid by Two Routes Based on Nucleophilic Substitution Reaction on Indole Nucleus
Takashi Kurauchi, Yoshiyuki Nagahama, Masakazu Hasegawa, Koji Yamada, and Masanori Somei*
*Faculty of Pharmaceutical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-0934, Japan
Abstract
Regioselective nucleophilic substitution reaction of 1-hydroxytrypta- mines led to establish two novel routes for the first synthesis of bufobutanoic acid. An effective synthesis of 5-benzyloxytryptamine from tryptamine is also reported.
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■ Convenient Direct Synthesis of Vinylogous Urea Derivatives Using Magnesium Amide-induced Amide/Nitrile Coupling
Kazuhiro Kobayashi,* Tomohide Kitamura, Ryoji Nakahashi, Akiko Shimizu, Keiichi Yoneda, Osamu Morikawa, and Hisatoshi Konishi
*Department of Materials Science, Faculty of Engineering, Tottori University, Koyama-minami, Tottori 680-8552, Japan
Abstract
The magnesium enolates, generated by treatment of acyclic (1) and cyclic tertiary amides (4) with a (diisopropylamino)magnesium reagent, reacted efficiently with nitriles (2) to afford the corresponding β-aminoacrylamides (3) and α-(α-aminoalkylidene)lactams (5). The formation of α-(2-pyrrolidinylidene)lactams (7) from the reactions of N-methyl-2-pyrrolidone and N-methyl-2-piperidone with a γ-cyanopropyl p-toluenesulfonate (6) is also described.
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■ Polycyclic Hydroxyquinones. Part 31. Regioselective Reactions of 6-Ethylsulfonyl-3-phenylfuro[3,4-d ]isoxazol-4(6H )-one Anion with Quinone Monoketals. Application to the Preparation of Heteroanthracyclinone Analogues
Raquel Alguacil, M. Victoria Martín, and M. Carmen Paredes*
*Instituto de Química Orgánica General (CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
Abstract
The development of a general strategy for the construction of heteroanthracyclinones based on an annelation reactions of the anion generated from 6-ethylsulfonyl-3-phenylfuro[3,4-d]isoxazol-4(6H)-one (3) with quinone monoketals is described.
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■ New Synthetic Applications of Phenylacetylphenylacetic Acids: A Divergent Synthesis of Benzo[a]carbazoles and Indolo[2,1-a]isoquinolines
Jacobo Cruces, Juan C. Estévez, Ramón J. Estévez,* and Luis Castedo
*Departamento de Química Orgánica e Unidade Asociada (C.S.I.C.) Universidade de Santiago de Compostela, 15706, Santiago de Compostela, Spain
Abstract
Here we describe a common access to benzo[a]carbazoles and indolo[2,1-a]isoquinolines from 2-(2’-nitrophenylacetyl)phenylacetic acids.
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■ Formal Total Synthesis of Aglaiastatin: Pd(0)-mediated Construction of Benzofurocyclopentane System
Takumi Watanabe, Yuichiro Shiraga, Tomio Takeuchi, Masami Otsuka, and Kazuo Umezawa*
*Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku Yokohama 223-0061, Japan
Abstract
Aglaiastatin, an antitumor alkaloid, contains fused pentacyclic system, including a benzofurocyclopentane system and a unique pyrrolopyrimidinone skeleton. In this study, synthesis of a keto aldehyde intermediate, a key intermediate in a previously reported procedure for total synthesis, was accomplished via Pd(0)-mediated benzofuran ring closure. Thus, a formal total synthesis of aglaiastatin was achieved.
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■ [4+2] Cycloaddition Reaction of 3-Hydrazono-1,1,1-trifluoro-2-alkanones to 4,5-Bis(trifluoromethyl)pyridazines
Yasuhiro Kamitori*
*Department of Chemical Science and Engineering, Faculty of Engineering, Kobe University, Kobe 657-8501, Japan
Abstract
Mechanisms for the reaction of 3-hydrazono-1,1,1-trifluoro-2- alkanons (1) to 4,5-bis(trifluoromethyl)pyridazines (2) in the presence of TFA are discussed on the basis of the 6-31G* level ab initio calculations. The results indicate a concerted [4+2] cycloaddition reaction of protonated 1 to be a key step for this reaction.
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■ Preparation of 2-Substituted Naphth[2,3-d]oxazole-4,9-diones via a Radical Chain Process
Pascal Rathelot, Yves Njoya, José Maldonado, Michel P. Crozet, and Patrice Vanelle*
*Laboratoire de Chimie Organique, Université de la Méditerranée, Faculté de Pharmacie, 27 boulevard Jean Moulin, 13385 Marseille Cedex 05, France
Abstract
A novel series of ethylenic naphth[2,3-d]oxazole-4,9-diones was synthesized via an SRN1 mechanism from the 2-chloromethylnaphth[2,3-d]oxazole-4,9-dione. This mechanism was confirmed by the inhibitory effects of the use of dark, bubbling oxygen, cupric chloride, p-dinitrobenzene and TEMPO.
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■ Total Synthesis of Optically Active m-Phenylene PGl2 Derivative: Beraprost
Hisanori Wakita, Hideo Yoshiwara, Hisao Nishiyama, and Hiroshi Nagase*
*Basic Research Laboratories, Toray Industries, Inc., 111 Tebiro, Kamakura, Kanagawa, 248-8555, Japan
Abstract
The optical isomers of m-phenylene PGI2 derivative, Beraprost, were synthesized in practical scales from optically active carboxy-cyclopenta[b]benzofurans (12 and 13) by Wittig and Wadsworth reactions as key reactions via the intermediate diols (16a and 16b).
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■ Transformation of 5,6,7,8-Tetrahydro-2H-1-benzopyran-2,8-diones with Hydrazines and Hydrazoic Acid: Synthesis of 8-Hydrazono-5,6,7,8-tetrahydro-2-oxo-2H-1-benzopyrans, Pyrano[2,3-c]azepines and Pyrido[2,3-c]azepines
Polonca Trebse, Lidija Vranicar, Irena Music, Slovenko Polanc, William C. Stevens, and Marijan Kocevar*
*Faculty of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, SI-1000 Ljubljana, Slovenia
Abstract
N-(5,6,7,8-Tetrahydro-2,5-dioxo-2H-1-benzopyran-3-yl)-benzamide (1a) reacts with nitrogen-containing nucleophiles (2) (hydrazines and hydroxylamine) to give the corresponding 8-hydrazono derivatives (3a-i) and the related hydroxyimino derivative (3j). The action of hydrazoic acid on 1a-b or 3a-b and 3e resulted in the formation of pyrano[2,3-c]azepines (4a-b). The pyranoazepine (4a) can be debenzoylated to 4b or transformed into pyrido[2,3-c]azepines (5a-b).
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■ An Unprecedented 1,8a-Bond Fission of an N -Formyl-1,2,3,4-tetrahydroisoquinoline Derivative under a Nitration Condition
Toshio Honda,* Masato Nishimura, Jun Itabashi, and Kazuo Kanai
*Faculty of Pharmaceutical Sciences, Hoshi University, Ebara 2-4-41, Shinagawa-ku, Tokyo 142-8501, Japan
Abstract
An unprecedented bond fission between the 1 and 8a positions of an N-formyl-1,2,3,4-tetrahydroisoquinoline derivative was observed under nitration conditions using nitric acid and acetic acid. The structures of the products and the proposed reaction mechanism were also described.
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■ Synthesis of Bactericides via Carbon Nucleophilic Addition on 1,3-Diarylprop-2-enones as Michael Acceptors
Mounir A. I. Salem,* Hassan M. F. Madkour, El-Sayed A. Soliman, and Naglaa F. H. Mahmoud
*Laboratory of Synthetic Organic Chemistry, Chemistry Department, Faculty of Science, Ain Shams University, Abbassiya 11566, Cairo, Egypt
Abstract
Treatment of α,β-unsaturated ketones (I) with malononitrile in presence of ammonium acetate afforded 2-amino-4,6-diarylnicotinonitriles (II) which reacted with aq. alc. KOH, CS2 (pyridine), CS2 (EtOH/NaOH), phenyl isothiocyanate and guanidine hydrochloride to yield the corresponding heterocyclic products (III-VII) respectively. When I was allowed to react with cyanoacetanilide, ethyl chloroacetate, benzyl cyanide, 4-chlorobenzaldehyde and potassium cyanide, it gave the Michael adducts (VIII-XII). Fusion of XIb with hydrazine hydrate afforded XIII whereas treatment of XIb with hydrazine hydrate and/or hydroxylamine hydrochloride gave XIVa and b respectively. The evaluation of the minimal inhibitory concentration (MIC) of some of the synthesized compounds was carried out.
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■ A Facile Synthesis of 1-Alkyl-7-azaisatins
Jiro Tatsugi,* Tong Zhiwei, Tomohiro Amano, and Yasuji Izawa
*Department of Applied Chemistry, Aichi Institute of Technology, Yachigusa, Yakusa-cho, Toyota 470-03, Japan
Abstract
1-Alkyl-7-azaisatins are synthesized from the reaction of 1-alkyl-7-azaindoles with bromine in dichloromethane and subsequent oxidation with N-bromosuccinimide - dimethyl sulfoxide reagent. 1-Alkyl-7-azaindoles are readily available in high yields from the reaction of sodium salt of 7-azaindole with the appropriate alkyl halides in dimethylacetamide.
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■ Synthesis of s-Triazolo[1,5-c]pyrimidines
Ravi B. Shankar* and R. Garth Pews
*Corporate Research and Development, The Dow Chemical Co., Midland, MI 48674, U.S.A.
Abstract
A cyclization method for the synthesis of s-triazolo[1,5-c]pyrimidines is discussed.
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■ Transition Metal Complexes of Derivatized Chiral Dihydro-1,2,4-triazin-6-ones. Part I. Nickel(II) Complex of (D)-3-Acetyl-5-benzyl-1-phenyl-4,5-dihydro-1,2,4-triazin-6-one Oxime. An Instance of a Carbon-Carbon Coupling Reaction
Ahmad S. Abushamleh, Mustafa M. El-Abadelah,* and Cäcilia M.-Mössmer
*Chemistry Department, Faculty of Science, University of Jordan, Amman, Jordan
Abstract
The reaction of (D)-3-acetyl-5-benzyl-1-phenyl-4,5-dihydro-1,2,4-triazin-6-one oxime (2) with nickel acetate in refluxing ethanol afforded the respective square planar Ni(II) complex. This is evidenced from an X-Ray study which reveals that the Ni(II) ion is coordinated to the ring N(4) and oxime nitrogen atoms. The crystallographic data of the complex (3) also unravelled that the nickel-complexation has led to the formation of one π-bond across the N(14)-C(15) bond and one σ-bond between a benzylic carbon atom of one ligand and the chiral (C5) carbon atom of the other ligand in the bis-ligand complex (3). Evidently, the complexed Ni(II) ion plays a template effect role in initiating such a cascade of π- and σ-bond forming reactions. 1H-, 13C-NMR and FD-MS spectral data of 3 are in full agreement with its molecular structure.
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■ A Practical Synthesis of 1,3-Oxazole
Cynthia M. Shafer and Tadeusz F. Molinski*
*Department of Chemistry, University of California, Davis, CA 95616, U.S.A.
Abstract
A short synthesis of oxazole (1,3-oxazole, 1) is described.
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■ A Novel Convenient Synthesis of 1,3,5,5-Tetrasubstituted Hexahydropyrimidine-4-thiones
Juraj Bernát, Pavol Kristian,* Janka Guspanová, and Igor Chomca
*Department of Organic Chemistry, P. J. Safárik University, 04167 Kosice, Slovakia
Abstract
Sodium salts of (2-substituted thiocarbamoyl)malonic acid diethyl esters (2a-d) obtained via reaction of isothiocyanates (1a-d) with sodium diethyl malonate afforded with formaldehyde and amine sulfate in water medium diethyl 1,3-disubstituted 4-thioxohexahydropyrimidine-5,5-dicarboxylates (3a-j). Reaction represents the simple and convenient way to synthesize the title compounds.
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■ Synthesis of a 5-Substituted Benzo[b]thiophene
Gregory S. Wayne,* Gregory S. Lannoye, Anthony R. Haight, Shyamal I. Parekh, Weijiang Zhang, and Richard R. Copp
*Chemical Process Research, D54P, Abbott Laboratories, North Chicago, IL 60064, U.S.A.
Abstract
The synthesis of a 5-substituted dimeric benzo[b]thiophene (3), utilizing a Friedel-Crafts alkylation and subsequent Newman-Kwart rearrangement, is described.
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■ Convenient Synthesis of 1-Substituted Derivatives of 4-([E ]-1-Propenyl)- and 4-Allyl-3-aminoisoquinolines
Sagun Tandel and Edward R. Biehl*
*Chemistry Department, Southern Methodist University, Dallas, TX 75275, U.S.A.
Abstract
A one-step synthesis of titled compounds from the reaction of α-allyl-α-cyano-o—tolunitrile with lithium amides and alkylithiums is described. The reaction of lithiated primary alkyl amines, allkyl- and aryllithiums at -78°C gave 1-substituted 4-([E]-1-propenyl)-3-aminoisoquinolines, whereas lithiated cyclic amides and 3-dimethylaminopropyl amide under similar conditions afforded 1-substituted 4-allyl-3-aminoisoquinolines. 1-Substituted 4-([E]-1-propenyl)-3-aminoisoquinolines were obtained as major product when reactions of the lithiated cyclic amides were performed at room temperature for 24 h. An explanation in terms of the effect of 4-substituents on the acidity of the α-methylene hydrogens is given.
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■ Synthesis of 2,2-Dimethyl-2H -chromenes
Albert Lévai,* Tibor Tímár, Péter Sebok, and Tibor Eszenyi
*Department of Organic Chemistry, Lajos Kossuth University, P.O.Box 20, H-4010 Debrecen, Hungary
Abstract
In the present review article, the most important procedures developed and utilized for the synthesis of 2,2-dimethyl-2H-chromenes are compiled and discussed. Special emphasis is layed on the most convenient and most important methods, viz. the dehydration of 2,2-dimethyl-4-hydroxychromans or the thermal rearrangement of phenyl propargyl ethers. However, less general and/or special procedures are critically discussed. Examples for the synthesis of nitrogen and sulfur analogues of 2,2-dimethyl-2H-chromenes have also been included.