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. 9, No. 12, 1978
Published online:
■ Photoaddition of Vinyl Ethers to N-Methylphtalimide. Competing 2+2 Processes
Paul H. Mazzocchi,* Saeko Minamikawa, and Michael Bowen
*Department of Chemistry, University of Maryland, College Park, Marykland 20742, U.S.A.
Abstract
The photochemical addition of vinyl alkyl ethers to N-methylphthalimide to give 3,4-benzo-6,7-dihydro-1-methylazepine-2,5-diones in a Π2 + σ2 process is found to compete with the Π2 + Π2 Paterno-Buchi reaction in this system.
Published online:
■ Reaction of Lactim Ethers with Carboethoxymethylpiperidines. A Synthesis of 1,9-Diazateroid
Takao Yamazaki,* Hiroki Takahata, Minoru Ishikura, and Masanori Nagata
*Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Toyama 930-0194, Japan
Abstract
Imine-enamine tautomerization was observed in methyl valelo-lactim (2) and methyl caprolactim (3), whereas rarely in methyl butyrolactim (1) on NMR. The evidence for the tautomerization was elucidated also by the chemical behaviors of the lactim ethers towards cyclic β-aminoesters such as, 2-carboethoxymethyl piperidine derivatives, which often gave two kinds of products probably resulted from both the imine and the enamine forms. This was applied to a synthesis of the 1,9-diazasteroid.
Published online:
■ Acid Catalyzed Methanolysis of N-Substituted 2-Amino-1,3,2-dioxaphosphorinane-2-oxides, an Observation of Retention Process
Toru Koizumu,* Yoshiko Kobayashi, and Eiichi Yoshii
*Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Toyama 930-0194, Japan
Abstract
Acid catalyzed methanolysis of cis N-substituted 2-amino-1,3,2-dioxaphosphorinane-2-oxides revealed that H+ catalyzed reaction proceeded by the complete inversion process while BF3 catalysis proceeded by the intervention of retention process.
Published online:
■ Reaction of o-Aminobenzamide Derivatives with Ethyl 3-Ethoxymethylene-2,4-dioxovalerate. Synthesis of Pyrrolo[1,2-a]quinazoline-1,5-diones
Takushi Kurihara* and Yasuhiko Sakamoto
*Faculty of Pharmaceutical Science, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan
Abstract
Reaction of ethyl 3-ethoxymethylene-2,4-dioxovalerate (1) with o-aminobenzamide derivatives gave 3-aminomethylene derivatives (4a,b and 5a), which were subsequently refluxed in ethanol to give rise to a mixture of pyrrolo[l,2-a]quinazoline-1,5-diones (6a,b and 7a) and 3,4-dihydro-4-oxoquinazoline analogue (8a,b and 9a) in moderate yields, respectively.
Published online:
■ Studies of Pyrazines. II. Synthetic Study of Hydroxypyrazine
Takeo Konakahara* and Yukio Takagi
*Department of Industrial Chemistry, Faculty of Science and Technology, Science University of Tokyo, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
Abstract
The effects of a reaction temperature and an alkali-addition velocity on the yield of hydroxypyrazine in the condensation of glycine amide hydrochloride with glyoxal, were discussed. The lower the reaction temperature, the higher was the yield of hydroxypyrazine, unless the reaction mixture was solidified. The effect of the alkali-addition velocity on the yield of the product was like that of pH on the rate of Shiff-base formation reaction, which shows a maximum value.
Published online:
■ Reactions of Benzo-1,2-dithiole-3-thione with N,N’-Dialkyl-1,2-diaminoethanes. Synthesis of o-Thioquinonemethides with a Ketene Aminal Group
Renji Okazaki, Kyung-Tae Kang, and Naoki Inamoto*
*Department of Chemistry, Scool of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033
Abstract
Benzo-1,2-dithiole-3-thione (2) reacted with N,N’-dialkyl-1,2-diaminoethanes (2) to give o-thioquinonemethides with a ketene aminal group (4-6) in high yields, which were found to be of considerable betain nature significantly different from previously known o-thioquinonemethides with a ketene thioacetal group (1).
Published online:
■ Selective N-Alkylation of Enaminone Anions Leading to 3-N-Aziridyl-, -Azetidyl-, and -Pyrrolidylcyclohex-2-en-1-ones
Hideo Iida,* Yoshifumi Yuasa, and Chihiro Kibayashi
*Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
Abstract
Double N-alkylation of 3-aminocyclohex-2-en-1-one (1) with 1,4-dibromobutane in the presence of sodium hydride gave 3-N-pyrroljdylcyclohex-2-en-1-one (6). The formation of the N-aziridyl and -azetidyL analogues (2 and 3) of 6 was achieved by internal N-alkylation of the N-ω-haloalkyl derivatives of 1 with appropriate strong bases.
Published online:
■ An Approach to the Skeleton of Rauwolfia Alkaloids: A General Synthesis of 3,8-Epoxy-7-keto-6-oxabicyclo[3.2.1]octane Derivatives
Toshio Suzuki, Seiko Kagawa, Akiko Tomino, Katsuo Unno, Tetsuji Kametani,* Tamiko Takahashi, and Yoshihiro Tanaka
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
Halolactonization of the Diels-Alder adduct (3a) derived from bis(trimethylsilyl)allene dicarboxylate (2) and furan, followed by a treatment of the products (5a) and (5c) with diazomethane, afforded the corresponding α,β-unsaturated methyl esters (5b) and (5d), respectively. Catalytic hydrogenation of both compounds provided the desired methyl esters (4a) and (4b) which were identical with the compounds derived from Arndt-Eistert reaction of the halolactonic acids (7a) and (7c), respectively.
Published online:
■ The Correction on the Structure of Diels-Alder Reaction Products of Furan Derivatives with Maleic Anhydride
Toshio Suzuki, Akiko Tomino, Seiko Kagawa, Katsuo Unno, Tetsuji Kametani,* Masataka Ihara, and Tamiko Takahashi
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
The structure of Diels-Alder adducts and related compounds prepared from furans and maleic anhydride was re-examined hy the 13C-NMR spectroscopy and our tentative structures were revised.
Published online:
■ Preparation of Polystyrene-bound 5-Deazaflavins and Their Use in Oxidation of Alcohol
Fumio Yoneda,* Yoshiharu Sakuma, Yoshiko Matsushita, and Yoshihiro Nitta
*Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-hon-machi, Kumamoto 862-0973, Japan
Abstract
The resins with 5-deazaflavin group attached to polystyrene via methylene linkage were prepared by condensation of the corresponding 10-alkyl-5-deazaflavins with chloromethyl- polystyrene. These resins oxidized benzyl alcohol under alkaline conditions to yield benzaldehyde in the same way as 5-deazaflavins themselves.
Published online:
■ A Dichotomy in the Reaction of 6-(N-Alkylanilino)-3-methyl-5-nitrouracils with a Mixture of Phospohrous Oxybromide and Dimethylformamide. Formation of Flavins or 5-Deazaflavins
Yoshihru Sakuma, Yoshiko Matsushita, Fumio Yoneda,* and Yoshihiro Nitta
*Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-hon-machi, Kumamoto 862-0973, Japan
Abstract
Treatment of 6-(N-alkylanilino)-3-methyl-5-nitrouracils (I) with a mixture of phosphorus oxybromide and dimethylformamide (POBr3-DMF) at 80° gave the corresponding isoalloxazines (flavins). On the other hand, treatment of I with POBr3-DMF at 150° led to the exclusive formation of pyrimido[4,5-b]quinoline-2,4(3H,10H)-diones (5-deazaflavins).
Published online:
■ The Chemistry of Diazaquinones
M. Quinteiro, C. Seoane, and J. L. Soto*
*Departamento de Química Orgánica I., Facultad de Química., Universidad Complutense de Madrid, Ciudad Universitaria, E-28040 Madrid, Spain
Abstract
This article presents a survey of the synthesis, properties and reactions of 3,6-pyridazinedione, 1,4-phthalazinedione and related compounds.