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. 23, No. 10, 1985
Published online:
■ Pyridazine XXVII. Acylation Reactions and Procedures for Regioselective Alkylation of (5-Amino-4-pyridazinyl)-arylketones
Norbert Haider and Gottfried Heinisch*
*Institute of Pharmaceutical Chemistry, University of Vienna, Währinger Strasse 10, A-1090 Vienna, Austria
Abstract
Various amides 2a-d,3,4 derived from (5-amino-4-pyridazinyl)arylketones were prepared. Amino ketone 1 was found to be attacked by alkyl halides exclusively at N-2 yielding iminium salts 9a,9b, whereas reaction of tosylamide 3 with methyl iodide/sodium hydride gave a mixture of two isomeric methylation products (5,8). However, condensation of 1 with ortho esters, followed by sodium borohydride reduction of the intermediate ethyl imidates 12a-c and subsequent oxidation provides a convenient procedure for the preparation of (5-alkylamino-4-pyridazinyl)-arylketones 7a-c.
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■ Syntheses of Macrocycles from L-Amino Acid (II)
Toyoshi Katagi* and Hiromi Kuriyama-Kataoka
*School of Pharmaceutical Science, School of Pharmaceutical Science, School of Pharmaceutical Science
Abstract
Syntheses of 30-membered macrocycles were achieved by using diglycolic acid, L-phenylalanine and L-leucine as constituents.
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■ Hydrolytic Cleavage of 6-Oxopurines after Intramolecular Acylation at N-3
Helmut Rosemeyer and Frank Seela*
*Laboratorium für Bioorganische Chemie, Fachbreich Chemie, Universität Paderborn, D-4790, Paderborn, Germany
Abstract
Reaction of 9H-hypoxanthin-9-yl propionic acid (2c) as well as of its 6-mercapto analogue (2d) with N-[3-(dimethylamino)propyl]-N’-ethylcarbodiimide hydrochloride results in an intramolecular acylation at N-3 followed by a spontaneous hydroxylation at C-2 and opening of the pyrimidine ring. The products of these reaction sequences are the imidazo[1,5-a]pyrimidines (5c,d) which were deformylated to give the compounds 6a,b. The half-life values of the ring transformations of 2c,d as well as of its isosteres 2a,b imply that the “over-all” kinetics are 1. independent of the structure of the five-membered ring and 2. strongly affected by the 6-substituent. It is proposed that the intramolecular acylation is the rate-limiting step of the reaction cascade.
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■ Azafluoranthene Alkaloids: A Reinvestigation of the Synthesis of 5,6-Dimethoxyindeno[1,2,3-ij]isoquinoline
Mary D. Menachery and Keith T. Buck*
*Fries and Fries Division, Mallinckrodt, Inc., 110 East 70th Street, Cincinnati, Ohio 45216, U.S.A.
Abstract
The title alkaloid has been synthesized via thermolysis of an isolated triazinium salt. The resulting dihydro alkaloid is described for the first time. The reported synthesis of the alkaloid was reinvestigated, with isolation of two products not previously obtained during its preparation.
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■ Organogermanium Compounds. Synthesis and Properties of Bioactive Germanium Sesquisulfides
Norihiko Kakimoto, Masanao Matsui, 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 bioactive germanium sesquisulfides (6) were investigated. Compound (6) prepared from the substitution reaction of trichlorogermyl adducts (2) with hydrogen sulfide seems to have the thiogermaadamantane structure from mass spectral data. It was found to have the unique bioactivities, such as those of an antitumor and antioxidant, and inhibitory activity towards enkephalin hydrogenase.
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■ On the Synthesis of Unsaturated 4(5H)-Imidazolines. 2. Semi-empirical SCF-MO(MNDO) Study on Geometric Factors influencing the Reaction Course
Carlos Cativiela,* José I. García, Carlos Jaime, José A. Mayoral, and Enrique Meléndez
*Departamento de Quimica Organica, Facultad de Ciencias -I Instituto de Ciencia de los Materiales de Aragón, Universidad de Zaragoza, E-50009 Zaragoza, Aragon, Spain
Abstract
Semi-empirical calculations by MNDO are achieved in order to explain the different reactivities of parent structures of anilides of (Z)-2-benzamidocinnamic acid and (Z)-2-benzamido-3-phenyl-2-butenoic acid to give the corresponding 4(5H)-imidazolones in the same conditions.
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■ A Stereoselective Introduction of an Amino Group to the 3-Position of a Readily Available 3-Hydroxyethylazetidinone Derivative
Tetsuji Kametani,* Shih-Der Chu, Shyh-Pyng Huang, and Toshio Honda
*Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
Abstract
A stereoselective introduction of an amino group at the 3-position of an azetidinone from a readily available 3-hydroxyethylazetidinone was described.
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■ Beckmann Rearrangement of 3,4-Dimethoxy-6-morphinanone Oxime
Ikuo Fujii, Michiko Irie, Kenji Hayakawa, and Ken Kanematsu*
*Institute of Synthetic Organic Chemistry, Faculty of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
Abstract
The Beckmann rearrangememts under neutral conditions of 3,4-dimethoxy-6-morphinanone oxime (1) and dihydrocodeinone oxime (2) proceed very smoothly but in the different ways to provide lactam (3) and hemiacetal (4), respectively.
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■ Synthesis of a Novel Ring System: Pyrido[3’.2’:4,5]isothiazolo[2,3-a]benzimidazole
Ricardo Bossio, Stefano Marcaccini,* Valerio Parrini, and Roberto Pepino
*CNR, Centro di Studio Sulla Chimica e la Struttura dei Composti Eterociclici e lolo Applicazioni, c/o Dipartimento di Chimica Organica "Ugo Schiff", c/o Dipartimento di Chimica Organica "Ugo Schiff", Via Gino Capponi 9, I-50121 Firenze, Italy
Abstract
Reaction between 2-mercaptonicotinic acid and o-phenylenediamine afforded 2-(2-mercapto-3-pyridyl)benzimidazole which underwent oxidative cyclization with bromine to give pyrido[3’,2’:4,5]isothiazolo[2,3-a]benzimidazole, a novel ring system.
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■ The Crystal and Molecular Structure of Pelargonindin Bromide Monohydrate
Norio Saito* and Katsuhiko Ueno
*Chemical Laboratory, Meiji-Gakuin University , 1518 Kamikurata-machi, Totsuka-ku, Yokohama 244-0816, Japan
Abstract
The structure of pelargonidin, 3,5,7,4’-tetrahydroxyflavylium, bromide monohydrate, obtained by the hydrolysis of pelargonin, the major pigment of Dahlia variabilis has been determined by the X-ray method. The crystals are triclinic space group P1 with a=8.929(2), b=11.360(3), c=7.299(2)Å, α=95.00(5), β=93.61(5), γ=93.35(5)° and Z=2. The structure was solved by the heavy atom method and refined by least-squares to a final R-value of 0.057 for 2351 observed reflexions. The molecule is nearly planar. The phenyl ring makes a dihedral angle of only 3.8° with the benzopyrylium plane. The sp2-sp2 single bond connecting the benzopyrylium portion and phenyl ring is 1.458Å. The bond lengths in the benzopyrylium portion show a charasteristic feature of resonance structure. The hydroxyl groups at the 7- and 4’-positions of pelargonidin cation form hydrogen bond with Br ions. The pelargonidin molecules related by the center of symmetries are stacked along the c axis. The hydrogen bonding schemes and stacking modes of anthocyanidins so far determined are summarized.
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■ Chemical Evidence for a Didehydroazepine in Reactions of Halogenoazepines with a Strong Base
Johannis W. Streef* and Henk C. van der Plas
*Laboratory of Organic Chemistry, Agricultural University, De Dreijen 5, 6703 BC Wageningen, The Netherlands
Abstract
The reaction of 5-X-2-(diethylamino)-3H-azepine (X=F, Cl) with t-butyllithium leads in high yield to a mixture of 4- and 5-t-butyl-2-(diethylamino)-3H-azepine. The ratio between both compounds is about 2,5:1, which ratio is independent of the substituent X. As intermediate in these conversions 2-(diethylamino)-3H-4,5-didehydroazepine is proposed.