HETEROCYCLES

■ Pyrimido[1,2-b]-1,2,4-triazolo[4,3-f]pyridazine, a Novel Ring System

Judit Kosáry, Endre Kasztreiner, and Márta Sóti

*Institute for Drug Research Ltd., H-1325 Budapest, POB 82, Hungary

Abstract

The novel ring system pyrimido[1,2-b]-1,2,4-triazolo-[4,3-f]pyridazine was prepared either by ring closure of 6-(3-hydroxypropylamino)-1,2,4-triazolo[4,3-b]pyridazine 2a in polyphosphoric acid and the hydrazone 7 with bromine. Compound 1 showed a positive inotropic effect.

■ The Preparation of Some (1)-Benzofurano-(2,3-c)-(6H,12H-1)-benzoxepin-6-ones

Vernon G. S. Box and Yvette A. Jackson

*Department of Chemistry, Mona Campus, University of the West Indies, Mona, Kingston 7, Jamaica

Abstract

The title compounds were prepared by the acid catalysed rearrangements of some 2-carbethoxy-3-aryloxymethylbenzofurans to the 2-carbethoxy-3-(2’-hydroxyarylmethyl)-benzofurans, followed by their lactonisation. These 2-carbethoxy-3-aryloxymethylbenzofurans do not undergo the Claisen rearrangement.

■ Pyrylium Salts from Friedel-Crafts Acylation of Isoparaffins: Isooctane

Michel Arnaud, Annette Pedra, Claude Erre, Christian Roussel, and Jacques Metzger

*Faculte des Sciences de St-Jerome , E.N.S.S.P.I.C.A.M., Avenu Escadrille Normandie-Niemen, 13397 Mareseille Cedex, France

Abstract

It is shown that acylation of isooctane in AlCl₃/CHCl₃ medium leads to 2,6-dialkyl-4-methylpyrylium salts, unsaturated ketones and isobutane. Compared to acylation of other isoparaffins, better yields are obtained due to an autocatalytic process.

■ Studies on Pyridazine Compounds, XIV. Cyclization of Pyridazinylhydrazones

Géza Szilágyi, Márta Sóti, Péter Mátyus, and Endre Kasztreiner

*Institute for Drug Research Ltd., H-1325 Budapest, POB 82, Hungary

Abstract

Under suitable thermal or basic conditions pyridazinylhydrazones are transformed to the desmotropic pyridazinylpyrazolinones, the structure of which was proven by alkylation and acylation.

■ A Phenanthroid Lactone, Steroid and Lignans from Aristolochia indica

Basudeb Achari, Soumitra Bandyopadhyay, Chitta R. Saha, and Satyesh C. Pakrashi

*Indian Institute of Chemical Biology, Calcutta-700 032, India

Abstract

Aristololide, a new phenanthroid lactone characterised as 1b, has been isolated from the roots of Aristolochia indica Linn., along with 5α-stigmastane-3,6-dione, (—)-cubebin and (—)-hinokinin.

■ Non-oxidative Photocyclization of 2-Aroyl-1-methylene-1,2,3,4-tetrahydroisoquinolines

Takeaki Naito, Kotomi Katsumi, Yukiko Tada, and Ichiya Ninomiya

*Kobe Women’s College of Pharmacy, Motoyamakita, Higashinad, kobe, Hyogo 658, Japan

Abstract

Non-oxidative photocyclization of the enamides (2c,d,e) in benzene at low temperature afforded a new type of the lactams (4c,d,e) and (8) which have a common dihydrobenzene moiety and were readily transformed into the corresponding dehydrolactams (5c,d,e) and (7), thus firmly established the reaction course of photocyclization of these enamides under non-oxidative condition.

■ Asymmetric Synthesis of Dibenzo[a,g]quinolizines Related to Photoberberine Alkaloids

Takeaki Naito, Kotomi Katsumi, Yukiko Tada, and Ichiya Ninomiya

*Kobe Women’s College of Pharmacy, Motoyamakita, Higashinad, kobe, Hyogo 658, Japan

Abstract

Reductive photocyclization of enamides in the presence of a chiral metal hydride complex was systematically investigated in order to establish as a general asymmetric route for the synthesis of berbines and 13-methylberbines.

■ Synthesis of Heterocyclic Compounds XXXV. Thiopyridones from α-Benzoylcinnamonitriles

M. Jesús Rubio, Carlos Seoane, and José L. Soto

*Departamento de Química Orgánica, Facultad de Química, Universidad Complutense de Madridas, Ciudad Universitaria, E-28040 Madrid, Spain

Abstract

2-Pyridothiones (IV) are obtained from the reaction of α-benzoylcinnamonitriles (I) with cyanothioacetamide (II). Disulphides V result as well from the reaction. Transformation of IV into V and of V into IV, as well as methylation of IV and their hydrolytic conversion into pyridones VI are also described. Pyridones VI can also be obtained from methylthiopyridines VIII.

■ Studies on Pyrimidine Analogues: Reaction of Isoxazolo[3,4-d]pyrimidine with Active Methylene Compounds

Attaluri Siva Prasad, Jagir Singh Sandhu, and Jogendra Nath Baruah

*Division of Natural Products Chemistry, Regional Reseach Labratory (CSIR), Jorhat-6, Assam, India

Abstract

5,7-Dimethylisoxazolo[3,4-d]pyrimidine-4,6(5H,7H)-dione is found to react with a variety of active methylene compounds yielding novel pyrido[2,3-d]pyrimidine-2,4(1H,3H)-dione oxides.

■ Selenium Substituted Spiro Phosphorus Heterocycles

Christo M. Angelov

*Department of Chemistry, Higher Pedagogical Institute, 9700 Shoumen, Bulgaria

Abstract

The reaction of cyclohexylideneethenylphosphonic acid and its esters with arylselenenyl chlorides leads to the formation of 4-arylseleno-2-oxo-1-oxa-2-phospha-spiro(4,5)-3-decene derivatives. The dichloride of this acid with the same reagents cyclized only in the presence of sulfur dioxide.

■ One-Pot Acylation System Using Pyrazinethiols

Akihiro Ohta, Makoto Shimazaki, Naomichi Tanekura, and Sadayuki Hayashi

*Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan

Abstract

3,6-Dialkyl-2-pyrazinethiolcarboxylic esters, prepared from 3,6-dialkyl-2-pyrazinethiols, sodium and acyl chlorides in DME, were found to be convenient acylating reagents for amines and hydroxy compounds. Preparation of 3,6-dialkyl-2-pyrazinethiolcarboxylic esters and the following acylation were achieved in a one-pot system. The competition reaction on benzoylation showed that this one-pot system gave rise to the selectivity between acylations of amines, alcohols, and phenols.

■ Furans and Pyrans from γ- and δ-Ketonitriles

José L. Soto, Carlos Seoane, Nazario Matrín, and Luis A. Blanco

*Departamento de Química Orgánica, Facultad de Química, Universidad Complutense de Madridas, Ciudad Universitaria, E-28040 Madrid, Spain

Abstract

The spontaneous cyclization of δ-ketonitriles resulting from the reaction of malononitrile with either 1,2,3-triaryl-3-chloropropanones (II) or 1,2,3-triarylpropenones (III) in a basic medium leads to 2-amino-4,5,6-triaryl-3-cyano-4H-pyrans (V). On the other hand II and III react with potassium cyanide and an aromatic aldehyde in a hydroalcoholic medium to give γ-ketonitriles which cyclize to 2-arylideneimino-3,4,5-triarylfufans (VIII).

■ A New Aporphine Alkaloid, Fissoldine from Fissistigma oldhamii (Hemsl.) Merr.

Sheng-Teh Lu and Yany-Chang Wu

*School of Pharmacy, Kaohsiung Medical College, 100 Shih Chuen 1st Rd., Kaohsiung 80708, Taiwan, R.O.C.

Abstract

A new aporphine alkaloid, fissoldine, has been isolated from Fissistigma oldhamii and elucidated as (R)-1,2-methylenedioxy-9-methoxy-11-hydroxynoraporphine (3) by the spectral and chemical evidences.

■ A Short Improved Synthesis of N-Substituted 5-Aza-2-oxa-3-oxo-bicyclo[2.2.1]heptanes

Margaret M. Bowers-Nemia and Madeleine M. Joullié

*Department of Chemistry, University of Pennsylvania, 231 South 34th Street Philadelphia, PA 19104-6323, U.S.A.

Abstract

N-Substituted 5-aza-2-oxa-3-oxo-bicyclo[2.2.1]heptanes are conformationally rigid models that have been used in several ¹H-NMR studies. They have previously been obtained by multistep processes. We have devised a one step synthesis for these compounds. The utility of this new route has been demonstrated for five differently N-substituted substrates.

■ Reactivity of 3-Diazopyrroles. Part 2.

Gaetano Dattolo, Girolamo Cirrincione, Anna Maria Almerico, Giuseppe Presti, and Enrico Aiello

*Instituto di Chimica Farmaceutica e Tossicologica, Università digli Studi di Palermo, Via Archirafi 32, 90123 Palermo, Italy

Abstract

3-Diazopyrroles 8 were prepared as key compounds for an alternative route to synthetize 1H-pyrrolocinnoline. However under the acidic conditions, decomposition and intermolecular coupling reactions were only observed.

■ The Chemsitry of Drugs. III. Acid Hydrolysis of Antimalarial 5-Alkoxy-6,6-dimethyl-5,6-dihydro-s-triazines

Balbir S. Bajwa, Nancy Acton, and Arnold Brossi

*Natural Products Research Center, Department of Chemistry, University of New Brunswick, Bag Service #45222, Fredericton, New Brunswick, E3b 5A3, Canada

Abstract

5-Alkoxy-6,6-dimethyl-5,6-dihydro-s-triazines undergo a fragmentation reaction in refluxing 1N HCl. The hydrolytic degradation of the antimalarial WR 99210 belonging to this class of compounds was investigated.

■ 1,2,3,5-Thiazolo[1,2-b]pyrazoliumolate-S,S-dioxides, Synthesis and Structure of a Novel Mesoionic System

Willy Friedrichsen, Andreas Böttcher, and Tony Debaerdemaeker

*Institut für Organische Chemie, Universität Kiel, Olshausenstrasse. 40, D-24098 Kiel, Germany

Abstract

The synthesis of the title compounds (2a and 2b) is described. The structure of 2b has been clarified by X-ray crystallography.

■ A New Method for the Synthesis of the 1,3-Diazetidin-2-ones by the Ozonolysis of the 2-Oxo-1,3-diazabicyclo[2.2.0]hex-5-enes

Takehiko Nishio, Naoko Nakajima, Choji Kashima, and Yoshimori Omote

*Department of Chemistry, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba-shi, Ibaraki, 305-8571, Japan

Abstract

Ozonolysis of the 2-oxo-1,3-diazabicyclo[2.2.0]hex-5-enes (2) in dichloromethane gave the 1,3-diazetidin-2-ones (3) in good yields, while ozonolysis of (2) in methanol gave the 1,3-diazetidin-2-ones (3), the cyclic acetals (4), and the unstable semi-acetals (5), which were identified as the acetate derivative (6).

■ Substituent Effects in the Reductive Photocyclization of Enamides

Takeaki Naito, Yukiko Tada, and Ichiya Ninomiya

*Kobe Women’s College of Pharmacy, Motoyamakita, Higashinad, kobe, Hyogo 658, Japan

Abstract

Variously substituted and hydrogenated lactams (5,6,8,10,11,15,16,17,20,and 25) were prepared by reductive photocyclization of a variety of enamides (4,7,9,14,19, and 22) which carry either electron-donating or attracting substituents on the benzoyl group of the respective enamide.

■ Synthesis of 13-Aza-16-oxa, 13-Aza-16-thia- and 13,16-Diazasteroidal Compounds through Cyclization of N-Acyliminium ion Intermediates

Shinzo Kano and Yoko Yuasa

*School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan

Abstract

5,5-Dimethyl-2,4-oxazolidinedione, 2,4-thiazolidinedione and 5,5-dimethylhydantoin were coupled with 2-(3,4-dihydro-1-naphthyl)ethyl alcohol by an application of Mitsunobu’s method to give the corresponding N-substituted products (5)-(7), respectively. Reduction of 5-7 with diisobutylaluminium hydride, followed by cyclization of the reduction products with formic acid yielded the 13-aza-16-oxa- (11), 13-aza-16-thia- (12) and 13,16-diaza-1,3,5 (10), 9(11)-estratetraen-17-one (13), respectively.

■ Carbon-13 Nuclear Magnetic Resonance in Alkaloid Chemistry

Thomas A. Broadbent and Edward G. Paul

*Department of Chemistry, Brigham Young University, Provo, UT 84602, U.S.A.