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. 75, No. 11, 2008
Published online: 29th May, 2008
■ Survey of Briarane-Type Diterpenoids — Part III
Ping-Jyun Sung,* Jyh-Horng Sheu, Wei-Hsien Wang, Lee-Shing Fang, Hsu-Ming Chung, Chen-Hao Pai, Yin-Di Su, Wei-Tse Tsai, Bo-Yuan Chen, Mei-Ru Lin, and Gung-Ying Li
*Taiwan Coral Research Center (TCRC), National Museum of Marine Biology & Aquarium, Checheng, Pingtung 944, Taiwan, R.O.C.
Abstract
The structures, names, biological activities, and references of 137 briarane-type diterpenoids are summarized. All briaranes mentioned in this review article were obtained from various octocorals including the specimens belonging to the genus Briareum, Ellisella, Gorgonella, Junceella, Subergorgia, Renilla, and Pachyclavularia.
Published online: 16th June, 2008
■ 1-Alkyl-3-ethylthio-4-(N-benzoyl-N-phenylamino)quinolinium Salts — Synthesis and Transformations
Andrzej Zieba* and Kinga Suwinska
*Department of Organic Chemistry, Medical University of Silesia, Jagiellonska 4, 41-200 Sosnowiec, Poland
Abstract
The reaction of 1-alkyl-4-(phenylamino)quinolinium 3-thiolates (2) with benzoyl chloride leads to 1-alkyl-3-benzoylthio-4-(phenylamino)quinolinium chloride (6). In the presence of DABCO, compounds (6) split off hydrogen chloride yielding 1-alkyl-3-benzoylthio-1,4-dihydro-4-(phenylimino)quinoline (7). Alkyla-tion of 4-(phenylimino)quinoline (7) with ethyl bromide leads to 1-alkyl-3-ethylthio-4-(N-benzoyl-N-phenylamino)quinolinium bromide (10). The structure of the obtained compounds were analyzed using 1H NMR (NOE) and 15N NMR spectral methods. The structure of compound (10a) was confirmed by X-ray analysis.
Published online: 7th July, 2008
■ Synthesis of 2-Substituted Pyrimido[5,4-b]indolizine Derivatives from Acetates of Baylis-Hillman Adducts
Min Jiang, Qian He, Chunhao Yang,* and Yuyuan Xie
*Department of Organic and Medicinal Chemistry, Shanghai Institute of Materia Medica, 555 Zu Chong Zhi Road, Shanghai 201203, China
Abstract
Novel tricyclic heterocycle pyrimido[5,4-b]indolizine derivatives 1 were synthesized conveniently in two steps. The key intermediates 2-substituted 5-[(pyridin-2-yl)methyl]pyrimidin-4(3H)-ones 2 were obtained by facile cyclization of the acetate of Baylis-Hillman adduct 3 and various amidine hydrochlorides 4 in the presence of sodium ethoxide. Treatment of 5-[(pyridin-2-yl)methyl]pyrimidin-4(3H)-ones 2 with phosphoryl chloride by reflux afforded fused 2-substituted pyrimido[5,4-b]indolizines 1 in high yield.
Published online: 3rd July, 2008
■ Regio- and Stereoselective Synthesis of Thiazole-Substituted Histamine and Adenine Derivatives by Nucleophilic Attack at Allenyl Isothiocyanate
Baker Jawabrah Al-Hourani, Klaus Banert,* Tobias Rüffer, Bernhard Walfort, and Heinrich Lang
*Organic Chemistry, Chemnitz University of Technology, Strasse der Nationen 62, 09111 Chemnitz, Germany
Abstract
The ambident oligonucleophiles histamine and adenine were reacted with allenyl isothiocyanate to yield N-(5-methylthiazol-2-yl) substituted derivatives of the natural products. Whereas histamine led selectively in three clean steps or alternatively in a one-pot procedure to a final product bearing three thiazole units, adenine gave exclusively the mono derivative with a thiazolyl group at N-7. The regio- and stereochemistry of these transformations were proved by single-crystal X-ray analyses of the title compounds.
Published online: 3rd July, 2008
■ Inter- and Intramolecular Cyclisation Reactions of Azoacetates Derived from Aryl Hydrazones of Ethylacetoacetate and Acetoacetanilides
Neil O’Halloran, John P. James,* Carol A. Downey, Patrick O’Malley, Thomas Duff, and Samuel Bertrand
*School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland
Abstract
The base induced cyclisations of azoacetates to azetidinones were investigated. In addition to the isolation of the desired products, it was found that 2-iminopyrrolidine-5-one derivatives as well as N-acyl hydrazides could be isolated when metal cyanides were employed as base. These entities were further modified to form pyrrolidine-2,5-diones and diazetidinones respectively.
Published online: 23rd June, 2008
■ A Facile Synthesis of 2-Difluoromethyl-6-methylpyridine-3,5-dicarboxylates
Isamu Katsuyama,* Kazumasa Funabiki, Masaki Matsui, Hiroshige Muramatsu, and Katsuyoshi Shibata
*OAP 25F, Hitec Co., Ltd., 1-8-30 Temmabashi, Kita-ku, Osaka-shi, Osaka 530-6025, Japan
Abstract
α,β-Unsaturated trifluoromethyl ketones 1 react with primary enamines 2 in the presence of phosphorus oxychloride / pyridine adsorbed on silica gel, providing 1,4-dihydro-2-methyl-6-trifluoromethylpyridines 3, which undergo dehydrofluorination by use of DBU/piperazine, giving moderate to high yields of 2-difluoromethyl-6-methylpyridine-3,5-dicarboxylates 4.
Published online: 3rd July, 2008
■ New Method of Synthesis of 5,6-Dihydro-4H-pyrrolo[1,2-a][1,4]benzodiazepines
Grigory V. Mokrov, Arkady M. Likhosherstov, Rainer Gewald, and Rudolf Schindler*
*elbion GmbH, Meissner Str. 191, 01445 Radebeul, Germany
Abstract
2,5-Dimethoxy-2-(dimethoxymethyl)tetrahydrofuran 1 reacted with anthranilic acid alkyl esters 2 in boiling acetic acid to give 2-(2-formylpyrrol-1-yl)benzoic acid esters 3. The reductive amination of 3 with primary arylalkylamines 4 led to 2-{2-[(arylalkylamino)methyl]pyrrol-1-yl}benzoic acids esters 5. Heating of the aminoesters 5 in xylene under reflux resulted in 5-(arylalkyl)-4,5-dihydro-6H-pyrrolo[1,2-a][1,4]benzodiazepin-6-ones 7. Lactams 7 were reduced by lithium aluminum hydride in toluene and ether solutions to give 5-(arylalkyl)-5,6-dihydro-4H-pyrrolo[1,2-a][1,4]benzodiazepines 8. The solid products 8 were recrystallized and the liquid ones were transformed into their salts with oxalic acid.
Published online: 7th July, 2008
■ The Synthesis and Microbiological Activity of 2-Mercapto-4-methoxypyridine-3-carbonitrile Derivatives
Agnieszka Miszke,* Henryk Foks, Kamil Brożewicz, Anna Kędzia, Ewa Kwapisz, and Zofia Zwolska
*Department of Organic Chemistry, Medical University of Gdansk, Al. Gen. Hallera 107, 80-416 Gdansk, Poland
Abstract
Synthesis of 2-(3-cyano-4-methoxypyridin-2-ylthio)acetic acid derivatives, starting either from 2-bromo-4-methoxypyridine-3-carbonitrile or 2-mercapto-4-methoxypyridine-3-carbonitrile is reported. The obtained products could be transformed by intramolecular Thorpe-Ziegler cyclization to related thieno[2,3-b]pyridines. Diazotization of 3-amino-N-(4-chlorophenyl)-4- methoxythieno[2,3-b]pyridine-2-carboxamide resulted in formation of a suitable pyridothienotriazine derivative. Some of the prepared compounds demonstrated noticeable bacteriostatic or tuberculostatic activity.
Published online: 12th June, 2008
■ Synthesis of 1-Aryl-1H-pyrrolo[2,3-b]pyridines (1-Aryl-7-azaindoles) by a Thermal Dehydration-Cyclization-Dehydrogenation Sequence of 2-Arylamino-3-(1-hydroxyalkyl)pyridines
Kazuhiro Kobayashi,* Seiki Fujita, Shuhei Fukamachi, and Hisatoshi Konishi
*Division of Applied Chemistry, Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan
Abstract
1-Aryl-1H-pyrrolo[2,3-b]pyridines (1-aryl-7-azaindoles) have been prepared in reasonable yields from the corresponding 2-arylamino-3-(1-hydroxyalkyl)pyridines, on heating at ca. 250 °C, through a successive dehydration/cyclization/dehydrogenation sequence.
Published online: 7th July, 2008
■ Regioselective Syntheses of 1-, 2-, 3- and 4-Aminoindolo[2,3-b]quinoxalines
Aurélie Jaouen, Philippe Helissey, Stéphanie Desbène-Finck, and Sylviane Giorgi-Renault*
*Laboratory of Therapeutic Chemistry, UMR CNRS N° 8638, Faculty of Pharmaceutical and Biological Sciences, University Paris Descartes, 4 avenue de l’Observatoire, 75270 Paris Cedex 06, France
Abstract
In view of the contradictory results published in the literature concerning the structure of the indoloquinoxalines obtained by condensation of isatin with an unsymmetrical benzene-1,2-diamine, regioselective syntheses of the 1-, 2-, 3-, and 4-aminoindolo[2,3-b]quinoxalines have been developed. With the four derivatives in hand, isomers obtained by direct cyclocondensations starting from amino or nitro substituted benzene-1,2-diamines could be unambiguously identified. The results of these studies show, on the one hand, that some previous findings need revision and, on the other hand, that the 1-amino isomer could be prepared in one step and in 58% yield.
Published online: 16th June, 2008
■ Mannich Reaction of 5-Hydroxy-β-carboline. Application to the Synthesis of Novel Oxazinopyrimidocarboline Derivatives
Samar Issa, Nadia Walchshofer, Issam Kassab, Jacques Gentili, Aziz Geahchan, and Zouhair Bouaziz*
*University of Lyon, Lyon, F-69003, France
Abstract
5-Hydroxy-β-carboline 4 was synthesized and submitted to the Mannich reaction towards formaldehyde and some primary amines. It undergoes an original reaction of bis-aminomethylation-cyclisation giving the oxazinopyrimidocarboline derivatives 5a-d. The structure of these compounds was confirmed by their high-resolution mass, IR, 1H NMR and 13C NMR spectral data.
Published online: 7th July, 2008
■ Synthesis and Alkylation of Sodium 4-Thioxo-1,4-dihydroquinoline-3-sulfinate
Leszek Skrzypek and Andrzej Maslankiewicz*
*Department of Organic Chemistry, The Medical University of Silesia, Jagielloñska Str. 4, 41-200 Sosnowiec, Poland
Abstract
Reaction of 4-chloro-3-quinolinesulfonyl chloride (1) with sodium hydrogen sulfide led to sodium 4-thioxo-1,4-dihydro-3-quinolinesulfinate (2). Compound 2 in reactions with alkyl halides was monoalkylated to sodium 4-alkylsulfanyl-3-quinolinesulfinate (3) or double alkylated directly to 4-alkylsulfanyl-3-alkanesulfonylquinolines (4).
Published online: 3rd July, 2008
■ A Facile Route to Pyrrolo[2,1-a]- and 1,2,3-Triazolo[5,1-a]dihydroisoquinolines
Tayseer A. Abdallah
*Department of Chemistry, Faculty of Science, University of Cairo, Giza 12613, Egypt
Abstract
Treatment of 3,4-dihydro-6,7-dimethoxy-1-methylisoquinoline 1 with α-bromoketones 2a-c in benzene in presence of triethylamine afforded the corresponding pyrrolo[2,1-a]isoquinoline 4. Also treatment of 3,4-dihydro-6,7-diethoxyisoquinoline-1-carbonitrile 10 with α-bromo ketones 2a,b,d under the same reaction condition afforded the corresponding pyrroloisoquinoline 12. While treatment of isoquinolinium salt 11 with p-tolyldiazonium chloride in ethanol afforded triazoloisoquinoline derivative 16.
Published online: 7th July, 2008
■ A Facile Synthesis of Some New 7,8-Dihydrospiro{imidazo[1,2-a]pyridine-7,3’-indolin}-2’-one Derivatives
Maher F. El-Zohry,* Thanaa A. Mohamed, and Essam M. Hussein
*Chemistry Department, Faculty of Science, Assiut University, Assiut 71516, Egypt
Abstract
2-Methylimidazole (1) reacted with 3-dicyanomethylidine-1-ethyl-2-oxoindoline (2) in ethyl acetate to afford 5-amino-6-cyano-7,8-dihydro-1’-ethylspiro{imidazo[1,2-a]pyridine-7,3’-indolin}-2’-one (8), which used as a key intermediate for the synthesis of fused spiroheterocyclic derivatives of imidazopyridopyrimidine and/or imidazonaphthyridine nucleus incorporated indoline moiety. The chemical structures of all synthesized compounds were elucidated by the elemental and spectroscopic analyses.
Published online: 23rd June, 2008
■ A New Method to Synthesize Famciclovir
Lei Luo, Guorong Chen, and Yuanchao Li*
*Chinese Academy of Sciences, Shanghai Institute of Materia Medica, 555 Zuchongzhi Rd., Zhangjiang Hi-Tech Park, Shanghai, 201203, China
Abstract
A new and efficient method has been reported for the synthesis of 2-amino-9-[4-acetoxy-3-(acetoxymethyl)butyl-1-yl]purine (famciclovir) starting from guanine. The route involves chlorination of guanine, optimized Mitsunobu reaction, coupling with diethyl malonate, hydrogenation, reduction and esterification, and the overall yield is about 29%. This method does not require any form of chromatographic purification to give pure famciclovir, and it is an industrially viable manufacturing process for this drug.
Published online: 23rd June, 2008
■ A New Efficient Method for the Three-Component Synthesis of 4(3H)-Quinazolinones
Mostafa Baghbanzadeh, Minoo Dabiri,* and Peyman Salehi*
*Department of Chemistry, Faculty of Science, Shahid Beheshti University, Evin, P.O. Box 19396-4716, Tehran 1983963113, Iran
Abstract
4(3H)-Quinazolinones were efficiently synthesised by the three component cyclisation-oxidation of isatoic anhydride, ammonium acetate and aromatic aldehydes in the presence of ceric ammonium nitrate in ethanol.
Published online: 3rd July, 2008
■ A Concise Synthesis of (-)-Cytoxazone
Van-Thoai Pham, Jae-Eun Joo, Yong-Shou Tian, Yong-Hyun Kim, Kee-Young Lee, Chang-Young Oh, Jin-Hyun Jeongc, and Won-Hun Hama*
*Natural Products Laboratory, College of Pharmacy, Sungkyunkwan University, 300 Chunchun-dong, Jangan-ku, Wuwon 440-746, Korea
Abstract
A concise, stereoselective synthesis of (-)-cytoxazone 1 was described. A key feature is highly diastereoselective reduction of the amino ketone to give the anti-amino alcohol directly, which is 2-oxazolidinone precursor.
Published online: 7th July, 2008
■ A Convenient One-Pot Three Component Approach to Synthesis of Highly Substituted Iminothiazolines
Heshmat Allah Samimi, Manouchehr Mamaghani,* and Khalil Tabatabaeian
*Department of Chemistry, Faculty of Sciences, University of Guilan, P.O. Box 41335-1914, Rasht, Iran
Abstract
An efficient one-pot three component method was developed for the synthesis of highly substituted 2-iminothizolines by the reaction of isothiocyanates, primary amines and α-bromoketones in ambient temperature. The reaction produced the desired products in a completely regioselective manner in excellent yields (78-94%).