HETEROCYCLES

■ Structures of Sculponeatin A, B, and C, Three New Diterpenoids Having Unique Acetal Structures from Rabdosia sculponeata

Sun Han-dong, Lin Zhow-wen, Xu Yun-long, Yoshinori Minami, Teruyoshi Marunaka, Tsuneo Togo, Yoshio Takeda, and Tetsuro Fujita*

*Faculty of Pharmaceutical Sciences, University of Tokushima, Sho-machi, Tokushima 770-8505, Japan

Abstract

Three novel diterpenoids, sculponeatin A, B, and C have been isolated from the leaves of Rabdosia sculponeata (Vaniot) Hara and their structures were deduced from spectroscopic and chemical evidence.

■ New Contributions to Protopine Chemistry

Luis Castedo,* Amelia Perelta, Alberto Puga, José M. Saá, and Rafael Suau

*Facultad de Química y Sección de Alcaloides, Deparamento de Química Orgánica, C. S. I. C., Santiago de Compostela, Spain

Abstract

Protopine undergoes electrophilic aromatic substitution at C-12 by reaction with Br₂/HOAc and HNO₃/HOAc. Simpler alternative methods for the obtention of dihydrocoptisine and 13-oxycoptisine from protopine are also described.

■ Reaction of 2,3,6-Trimethylpyrimidin-4-one and Dimethyl Acetylenedicarboxylate

Takao Yamazaki,* Junko Tanii, Yoshiro Hirai, and Katsuhide Matoba

*Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Toyama 930-0194, Japan

Abstract

Treatment of 2,3,6-trimethylpyrimidin-4-one with dimethyl acetylenedicarboxylate(DMAD) gave tetramethyl 2,5-dimethyl-4-oxo-1,5-diazabicyclo[4.4.1]undecane-2,7,9-triene-7,8,9,10-tetracarboxylate(II) and tetramethyl 1,4,10-trimethyl-2-oxo-1,5-diazacyclodecane-3,5,7,9-tetraene-6,7,8,9-tetracarboxylate (III) in 36.2 and 27.9% yields, respectively. The reduction products with sodium borohydride and the catalytic-reduction products of II or III are also discussed.

■ Effect of Borate on the Decomposition of 2,4-Dihydroxy-7-methoxy-1,4-benzoxazin-3-one, a Hydroxamic Acid from Gramineae

Francisco J. Pérez and Hermann M. Niemeyer*

*Departamento de Química, Facultad de Ciencias, Unversidad de Chile, Casilla 653, Santiago, Chile

Abstract

Borate anion catalyzed the decomposition of the title compound, a resistance factor of Gramineae. The effect was attributed to the formation of a complex between borate and the open-chain hydroxamic acid intermediate in the decomposition reaction.

■ Formation of Dithioether Diactions of Cyclic Dithioethers in Concentrated Sulfuric Acid

Hisashi Fujihara, Akira Kawada, and Naomichi Furukawa*

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

Abstract

The dithioether dications of 5H,7H-dibenzo[b,g][1,5]dithiocin, 6H,12H-dibenzo[b,f][1,5]dithiocin, and 1,6-dithiacyclodecane were formed in the reaction of the corresponding S-oxides with conc. H₂SO₄.

■ Novel Rearrangement of 3-Acyl-5-acylamino-2,3-dihydro-1,3,4-thiadiazole 1-Oxides into 1,3,4-Oxadiazoles

Seiju Kubota,* Kouhei Toyooka, Naoya Yamamoto, Takayuki Kasai, and Masayuki Shibuya

*Faculty of Pharmaceutical Sciences, University of Tokushima, Sho-machi, Tokushima 770-8505, Japan

Abstract

Thermally, or in the presence of p-toluenesulfonic acid, 3-acyl-5-acylamino-2,3-dihydro-1,3,4-thiadiazole 1-oxides are transformed into 1,3,4-oxadiazoles, carbonyl compounds and sulfur.

■ First Synthesis of 4-Imidazolidinone

Yoshihiro Nitta,* Tamie Yamaguchi, and Toshiko Tanaka

*School of Pharmacy, Hokuriku University, 3-Ho, Kanagawa machi, Kanazawa 920-1181, Japan

Abstract

First synthesis of 4-imidazolidinone has been achieved via Beckmann rearrangement of 1-alkoxycarbonylazetidin-3-one oxime sulfonates with alumina, followed by removal of the alkoxycarbonyl groups.

■ Synthesis of Terpenoidal Alkaloid, Fabianine

Teruyo Sugita,* Junko Koyama, Kiyoshi Tagahara, and Yukio Suzuta

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

Abstract

Synthesis of a terpenoidal alkaloid, fabianine, was accomplished by application of Diels-Alder reaction of 1,2,3-triazine with enamine.

■ Facile Synthesis of 2-Substituted Indoles from o-Bromoaniline

Takao Sakamoto, Yoshinori Kondo, and Hiroshi Yamanaka*

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan

Abstract

The condensation of ethyl o-bromocarbanilate (4) with trimethylsilylacetylene in the presence of dichlorobis(triphenylphosphine)palladium, followed by treatment with sodium ethoxide in boiling ethanol gave indole (3a) in 72 % overall yield from 4. Similarly, 2-substituted indoles (3b,c) were synthesized from 4 and the corresponding 1-alkynes.

■ Oxidation of 2,5-Dihydro-1,2,3-triazines by m-Chloroperbenzoic Acid

Takashi Itoh, Akio Ohsawa, Terumitsu Kaihoh, and Hiroshi Igeta*

*School of Pharmaceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan

Abstract

2,5-Dihydro-1,2,3-triazines were oxidized by m-chloroperbenzoic acid to give only 1,2,3-triazine 2-oxides, while the oxidation of 1,2,3-triazines yielded the mixtures of 1- and 2-oxides. In case of adopting 2-methyl-2,5-dihydro-1,2,3-triazines as starting materials, 2-methyltriazoles and 2,5-dihydro-5-oxo-1,2,3-triazines were obtained.

■ Reaction of Cyclic Thioimidates with Methyl 3-Oxo-4-pentenoate (Nazorav‘s Reagent). Total Synthesis of (+)-Epi-lupinine

Hiroki Takahata, Kyoko Yamabe, Toshiaki Suzuki, and Takao Yamazaki*

*Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Toyama 930-0194, Japan

Abstract

Annulation of cyclic thioimidates with Nazarov’s reagent in the presence of mercuric chloride gave indolizidine and quinolizidine derivatives. Stereospecific transformation of the quinolizidine to (+)-epi-lupinine is described.

■ Honyumine, a New Linear Pyranoacridone Alkaloids from Citrus grandis Osbeck

Tian-Shung Wu,* Shiow-Chyn Huang, Ting-Ting Jong, Jeng-Shiow Lai, and Hiroshi Furukawa

*Department of Applied Chemiastry, Providence College of Arta and Science, Shalu 43309, Taichung Hsien, Taiwan, R.O.C.

Abstract

A linear pyranoacridone alkaloid, honyumine, was isolated from the root bark of Citrus grandis Osbeck, and the structure was assigned as formula 1.

■ Preparation of New 3-Substituted N-Bensyl-5-phenylpyrrolin-2-ones

Ali Abdul Hussain Saeed*

*Department of Chemistry, College of Science, University of Basrah, Basrah, Iraq

Abstract

Amination of γ-benzoylpropionic acid by benzyl and p-chlorobenzylamine gave new 3-substituted N-benzyl-5-phenylpyrroline-2-ones in high yield. The products were identified by nmr, ir, mass, and uv-visible spectrosoopy.

■ A 2-D NMR Structure Determination of Guan-Fu Base Z, a New Diterpene Alkaloid from the Chinese Herb Guan-Bai-Fu-Tzu (Aconitum koreanum)

Manfred G. Reinecke,* William H. Watson, De chang Chen, and Wen mei Yan

*Department of Chemistry, Texas Christian University, Fort Worth, Texas 76129, U.S.A.

Abstract

By analysis of the ¹H-, ¹³C-, and 2-D-nmr spectra (DEPT, ¹J-HETCOR, ^2,3J-HETCOR, HOMCOR) of a new alkaloid, Guan-fu base Z, from Aconitum koreanum its structure was determined to be that of 2-isobutyryl-14-hydroxyhetisine. All the carbon and all but two of the hydrogen resonances could be assigned.

■ Synthesis of Vinca Alkaloids and Related Compounds. XXVIII. Novel Type Rearrangement of an Indole[2,3-a]quinolizidine into Indolizino[8,7-b]indole

Zsuzsanna Kardos-Balogh, Ferenc Sóti, Mária Incze, Mária Kajtár-Peredy, and Csaba Szántay*

*Central Research Institute for Chemistry, Hungarian Academy of Sciences, H-1025 Budapest, Pusztaszeri ut 59-67, P.O.Box 17, Hungary

Abstract

Internal acylation of indolo[2, 3-a]quinolizidine derivatives may lead either to 3-acylindolenines or to indolizino[8,7-b]indole derivatives depending on the structural properties of the starting materials.

■ Nitrogen Brodgehead Compounds. Part 58. Nucleophilic Ring Cleavage of 1-Thia-2a,5a-diazaacenaphthene Ring

István Bitter,* Gábor Tóth, Béla Pete, István Hermecz, Kálmán Simon, and Zoltán Mészáros

*Department of Organic Chemical Technology, Technical University of Budapest, H-1521 Budapest, Gellért tér 4, Hungary

Abstract

1-Thia-2a,5a-diazaacenaphtene ring is cleaved by amines affording thiazolo[4,5-b]pyridine derivatives which undergo degenerate ring transformation.

■ On the Photo-chemical and Thermal Reactions of the Cyclobutene-iron Complexes Involved in Heteroarotic Bicyclo[3.2.0]heptadiene System

Makoto Nitta,* Hiroyuki Miyano, and Tomoshige Kobayashi

*Department of Chemistry, School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan

Abstract

Photochemical reaction of tetracarbonyl(6-7-η-4-phenyl-2-oxa-3-azabicyclo[3.2.0]hepta-3,6-diene)iron to give 2-phenylpyridine and 2-formyl-5-phenylpyrrole was studied. Furthermore, photochemical and thermal reactions of tetracarbonyl(6-7-η-2-ethoxycarbonyl-2,3-diazabicyclo[3.2.0]hepta-3,6-diene)iron were found to undergo decomplexation, N-N bond cleavage leading to 1-(N-ethoxycarbonyl)amino-4-cyano-1,3-butadiene, and dimerization of the cyclobutene moiety incorporating carbonyl group.

■ On the Reactiond of 2-Chloronicotinic Acid with 2-Aminobenzothiazole

Javier Garin, Enrique Meléndez, Francisco L. Merchan,* and Tomás Tejero

*Department of Chemistry, University of Zaragoza, 50009-Zaragoza, Spain

Abstract

The results of the reaction of 2-chloronicotinic acid with a series of 2-aminobenzothiazoles are reported. Under reflux of xylene the major product is the corresponding N-(2-benzothiazolyl)-1,2-dihydro-2-oxonicotinamide. Its structure is confirmed by an alternative synthesis and a possible explanation for its formation is provided. The results of the reaction of 2-aminobenzothiazole with 2-chloronicotinoyl chloride and methyl 2-chloronicotinate are also summarized.

■ s-Triazolo[4,3-a][1,3]diazacycloalkanes III. A Novel Synthesis of 2-Aryl-3-oxo-2,3,5,6,7,8-hexahydro-s-triazolo[4,3-a]pyrimidines

Izabella Krezel*

*Department of Pharmaceutical Chemistry, 90-145, Lodz, Narutowicza 120a, Poland

Abstract

A novel synthesis of s-triazolo[4,3-a]pyrimidines is described. Arylhydrazine hydrochlorides react easily with 1-ethoxycarbonyl-2-methylthio-1,4,5,6-tetrahydropyrimidine to form hydrochlorides of cyclic arylaminoguanidines, which are then cyclized in aqueous K₂CO₃ medium into s-triazolo[4,3-a]pyrimidines.

■ Synthesis of Pyridazine, Pyridazin-3-one, 2-Aminopyrrole and 2,5-Diaminopyridine Derivatives from Dicyanomethylene Compounds

Abdou Osman Abdelhamid* and Nosrat Mostafa Abed

*Department of Chemistry, Faculty of Science, University of Cairo, Giza, Egypt

Abstract

Aromatic diazonium chlorides react with dicyanomethylene compounds 1-3 and 18 to give the hydrazone derivatives which are readily cyclized into pyridazine 8-10 and pyridazine-3-one 19 respectively. 2-Aminopyrrole 11-13 and dihydropyridazin-3-one 20 are obtained by the reaction of 8-10 and 19 with zinc dust in the presence of acetic acid. Also the reaction of acetoacetanilide with malononitrle in acetic acid and piperidine as a catalyst was studied. The structures of the compounds obtained have been assigned on the basis of elemental analyses and spectral data.

■ Demethylations in the Cularine Series

Angel Rodriguez de Lera, Carmen Villaverde, and Luis Castedo*

*Facultad de Química y Sección de Alcaloides, Deparamento de Química Orgánica, C. S. I. C., Santiago de Compostela, Spain

Abstract

Selective demethylation in 7,4’,5’-substituted cularine compounds can be achieved under two different sets of conditions (acidic and nucleophilic). Less satisfactory results are obtained in the 7,3’,4’-substituted analogs.

■ The Reduction of Trifluoroacetophenone by Methyl-substituted Dihydronicotinamides

Jan Bossaerts, Roger Dommisse, and Frank Alderweireldt*

*Labratory of Organic Chemistry, University of Antwerp (RUCA), Groenenborgerlaan 171, B-2020 Antwerp, Belgium

Abstract

In a series of methyl-substituted 1-(2,6-dichlorobenzyl)-1,4-dihydronicotinamides, compounds with a methyl group α to the pyridine nitrogen have a free energy of activation which is at least 7.5 kJ/mol lower than those without methyl or with methyl on the 5-position.

■ Solvent and Temperature Effects on the Nucleophilic Addition of Organolithiums to 3-(4,4-Dimethyloxazolin-2-yl)pyridine. Synthesis of Stabilized 1,2-, 1,4- and/or 1,6-Dihydropyridines

Sushil K. Dubey and Edward E. Knaus*

*Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada

Abstract

The reaction of 3-(4,4-dimethyloxazolin-2-yl)pyridine (1) with nucleophilic organolithium reagents afforded stabilized N-unsubstituted 1,2-, 1,4- and/or 1,6-dihydropyridines. Reaction of 1 with phenyllithium gave a mixture of 1,2- (2) and 1,4-dihydropyridines (3) whereas reaction with n-butyl- and methyllithium afforded a mixture of 1,2- (2), 1,4- (3) and 1,6-dihydropyridines (4). The regiochemistry of the nucleophilic substitution reaction was dependent upon reaction solvent, reaction temperature and the nature of the organolithium reagent. Reactions carried out using the less polar ether as solvent, provided higher yields of C-2 (2) and C-6 (4) substituted products, whereas reactions performed in tetrahydrofuran provided higher yields of C-4 substituted products (3). A decrease in reaction temperature, increased the yield of the 1,4-dihydro isomer (3) in both solvents. Reactions employing phenyllithium were more regioselective than those utilizing n-butyl- and methyllithium.

■ New Synthesis of Dihydro- and Tetrahydro-1,5-benzodiazepines by Reductive Condensation of o-Phenylenediamine and Ketones in the Presence of Sodium Borohydride

Hilda R. Morales, Arturo Bulbarela, and Rosalinda Contreras*

*Departmento de Química del Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional, Apartado 14-740, México, D.F., 07000, Mexico

Abstract

Dihydro- and tetrahydro-benzodiazepines have been synthesized from o-phenylenediamine dihydrochloride and aliphatic ketones in the presence of sodium borohydride.

■ A Novel Synthesis of Benzo-1,4-dithiene

Benito Alcaide, Joaquín Plumet,* and Ignacio M. Rodriguez-Campos

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

Abstract

A novel synthesis of benzo-1,4-dithiene from1-oxanorbornen-2-one is described.

■ Polycyclic N-Hetero Compounds. XXI. Synthesis of Novel Ring System, 4H-Imidazo[1’,2’:1,6]pyrimido[5,4-d][1]benzazepine as B-Homo-6,11,13,15-tetraazastereoidal Analogue

Takashi Hirota,* Masami Fukukoto, Kenji Sasaki, Tetsuo Namba, and Shohei Hayakawa

*Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Okayama 700-8530, Japan

Abstract

A synthesis of 4H-imidazo[1’,2’:1,6]pyrimido[5,4-d][1]benzazepine (XIIIa) having a novel ring system is described. Methyl anthranilate (IVa) was converted to 4-(2-hydroxyethylamino)-6,7-dihydro-5H-primido[5,4-d][1]benzazepine (XIa) in several steps and XIa was cyclized to XIIIa. A synthesis of 8-chloro derivative of XIIIa is also described.

■ Synthesis of (1,6aβ,10aβ)-Decahydro-5-methyl-1-phenyl-1H-2,5-benzoxacine

John H. Musser,* Philip F. VonVoightlander, and Jacob Szmuszkovicz

*CNS Research, The Upjohn Company, Kalamazoo, MI 49001, U.S.A.

Abstract

The synthesis of epimeric (1,6aβ,10aβ)-decahydro-5-methyl-1-phenyl-1H-2,5-benzoxazines is described.

■ Deoxydative Substitutions of Pyridine 1-Oxides by Thiols

Ludwig Bauer* and Supalik Prachayasittikul

*Department of Medical Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, P.O.Box 6998, Chicago, IL 60680, U.S.A.

Abstract

Deoxydative substitutions of pyridine 1-oxides by thiols in the presence of a variety of acid chlorides and anhydrides provide a mixture of 2- and 3-pyridyl sulfides. In addition to these sulfides, there were also isolated some interesting tetrahydropyridyl sulfides from some of the reactions conducted in acetic anhydride. Modes of formation of the various products are discussed.

■ The Reactivity of N-Substituted Pyridinium Salts

Wanda Sliwa*

*Institute of Chemistry, Pedagogical University, 25-020 Kielce, Poland

Abstract

Reactions of N-substituted pyridinium salts, along with some data concerning their properties and applications are described.

■ Synthesis of Heterocycles Using Trifluoropyruvic Acid Hydrate

M. Elsaid Mustafa, Akio Takaoka, and Nobuo Ishikawa

*Department of Chemical Technology, Faculty of Engineering, Tokyo Institute of Technology, 2-12-1,Oh-Okayama, Meguro-ku, Tokyo 152-8552, Japan