HETEROCYCLES

■ Contents

■ The Chemistry of Calixpyrroles

Vinod K. Jain* and Hiren C. Mandalia

*Department of Chemisitry, School of Sciences, Gujarat University, Navrangpura, Ahmedabad 380009, Gujarat, India

Abstract

The calixpyrroles (meso-octasubstituted porphyrinogens), which are easy to make and functionalize, are a class of old but new hetero-calixarene analogue. This comprehensive review summarizes the progress made in chemistry of calixpyrroles in terms of their synthesis, structure, conformation, functionalization and applications in various fields.

■ Preparation and Structure of Bicycloalkane-Condensed Aryldiaziridines Accompanied by Pyrimidines

Pál Sohár, Antal Csámpai, Reijo Sillanpää, Ferenc Fülöp, and Géza Stájer*

*Institute of Pharmaceutical Chemistry, University of Szeged, P.O.Box 427 H-6701 Szeged, Hungary

Abstract

Di-exo- and di-endo-2-aminonorbornane/enemethanamines 1-3, di-exo-oxanorbornene derivative 4 and cis-cyclohexane and trans-4-cyclohexene analogues 5, 6 were reacted with p-chlorobenzaldehyde in the presence of N-bromosuccinimide in dichloromethane. Via the reactions of 1-6, condensed diaziridines 7-12 accompanied by pyrimidine derivatives 13-16 were prepared after isolation with column chromatography. The mechanisms proposed for alternative transformations were supported by DFT calculations. The structures of the new compounds were proved by IR and NMR spectroscopy and, for 7, 9 and 12, also by means of X-ray crystallography.

■ Domino Inverse Electron Demand Diels-Alder Reactions of Chromones with Ethyl Vinyl Ether

Jorge Heredia-Moya, Karsten Krohn,* Ulrich Flörke, Hernán Pessoa-Mahana, Boris Weiss-López, Ana Estévez-Braun, and Ramiro Araya-Maturana*

*Department of Organic and Physical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Casilla 233, Santiago 1, Chile

Abstract

(E)-Ethyl 3-(4-oxo-4H-chromen-3-yl)acrylate (3), (E)-3-(4-oxo-4H-chromen-3-yl)-2-propenenitrile (12) and their 5-hydroxy-derivatives 11 and 13 undergo alternative, solvent dependent, domino reactions with ethyl vinyl ether. Inverse electron demand Diels-Alder (IEDDA)-elimination-IEDDA generates isomeric tetracycles 15a-d and 16a-d. Instead, IEDDA-elimination-intramolecular elimination reactions provides xanthone 17 or 2-hydroxybenzophenones 18a-d, respectively. In non-polar solvents propenenitriles 12 and 13 experience a third alternative domino sequence: IEDDA-elimination-ene reaction, yielding the highly functionalized tricyclic compounds 21 and 22.

■ Synthesis of Novel Dipyrido-1,4-thiazines

Beata Morak-Mlodawska and Krystian Pluta*

*Department of Organic Chemistry, The Medical University of Silesia, Jagielloñska 4, 41-200 Sosnowiec, Poland

Abstract

An efficient synthesis of novel type of dipyrido-1,4-thiazine (4) was elaborated in the reactions of two pairs of 3,4-disubstituted pyridines in DMF. The reactions proceeded through the S→N type of the Smiles rearrangement of the resulting 4,4’-dipyridinyl sulfide. In the case of formation of 10-(3’-nitro-4’-pyridinyl)-2,7-diazaphenothiazine (5) double rearrangement was observed. 10H-2,7-diazaphenothiazine (4) was N-alkylated, N-arylated and N-heteroarylated to give 10-substituted (alkyl, arylalkyl, aryl, heteroaryl and dialkylaminoalkyl) derivatives (5) and (17-29). The NMR spectra were assigned with the help of the ¹H-¹H correlation (COSY) and NOE experiment of the methyl derivative (17). The crucial 10H-2,7-diazaphenothiazine (4) showed promising anticancer activity.

■ 1-Substituted 4-Hydroxy-3-quinolinesulfonic Acids – Preparation and Structures

Leszek Skrzypek* and Kinga Suwinska

*Department of Organic Chemistry, The Medical University of Silesia, Jagiellonska 4, 41-200 Sosnowiec, Poland

Abstract

1-Methyl and 1-ethyl-1,4-dihydro-4-oxo-3-quinolinesulfonic acids were synthesized from 4-chloro-3-quinolinesulfonyl chloride. It was shown that the acids and their 1-H substituted analogues form a betain having a hydroxy substituent located in position 4 and a sulfonate anion group in position 3. However, the sodium salts of the acids take a form of a quinolone tautomer.

■ Intramolecular Nitrilimine Cycloadditions to the Thiophene and the Furan Rings

Giorgio Molteni,* Sara Mondini, and Alessandro Ponti

*Dipartimento di Chimica Organica e Industriale, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy

Abstract

The dipolarophilic behaviour of furan and thiophene rings have been exploited in the intramolecular cycloadditions of nitrilimines. These labile intermediates were generated from the corresponding hydrazonoyl chlorides by treatment with silver carbonate. The extent of formation of tricyclic cycloadducts was strongly dependent on the substitution pattern of the heteroaromatic ring, thus reflecting the HOMO-dipole controlled nature of the cycloaddition.

■ Stereoselective Synthesis of Polyfunctionalized Aziridines

Luigino Troisi,* Catia Granito, Emanuela Pindinelli, and Ludovico Ronzini

*Department of Sciences and Biological and Environmental Technologies, University of Lecce, Via Prov.le Lecce-Monteroni, 73100 Lecce, Italy

Abstract

1,2,3-triHeterocycle-substituted aziridines were prepared by coupling of (α-chloroalkyl) oxazolinyllithium compounds with diheteroaryl imines. The trapping by different electrophiles of the corresponding aziridinyl anions, generated by treatment with strong bases, was investigated. The stereoselectivity of the synthesis and the functionalization reactions was studied highlighting the different stabilizing effects of the heterocycle substituents.

■ Synthesis of Thymine Polyoxin C by Using L-Threonine Aldolase-Catalyzed Aldol Reaction

Toshihiro Nishiyama, Swapnil Surendra Mohile, Tetsuya Kajimoto,* and Manabu Node*

*Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan

Abstract

Thymine polyoxin C (2), a common partial structure of polyoxin H (3) and J (4) having anti-fungal activity, was formally synthesized from D-ribose in good overall yield by using L-threonine aldolase-catalyzed reaction as a key step, which affords novel β-hydroxy-α-L-amino acids from glycine and aldehydes in an aqueous medium.

■ Synthesis of 1,2,4-Triazolo[3,2-b]benzothiazoles by Photolysis of Sulfilimines Having a (Methylthio)carbonimidoyl Group

Masahiko Takahashi* and Shohtaroh Satoh

*Department of Materials Science, Faculty of Engineering, Ibaraki University, Hitachi, Ibaraki 316-8511, Japan

Abstract

The reaction of dimethyl N-(2-benzothiazolyl)dithiocarbonimidates (4) with N-unsubstituted S,S-diphenylsulfilimine (1) gave N-[N-(2-benzothiazolyl)methylthiocarbonimidoyl]-S,S-diphenylsulfilimines (5), which were cyclized by phtolysis to 1,2,4-triazolo[3,2-b]benzothiazoles (7).

■ Synthetic Methods for Preparing 1,3-Di(2-pyridyl)azulene

Mitsunori Oda,* Sayaka Kishi, Nguyen Chung Thanh, and Shigeyasu Kuroda

*Department of Chemistry, Faculty of Science, Shinshu University, Asahi, Matsumoto 390-8621, Japan

Abstract

The title compound was synthesized either by introduction of another pyridine ring into 3-(2-pyridyl)-1,2,3,8-tetrahydroazulen-1-one or by Stille and Negishi double cross-coupling reactions of 1,3-dihaloazulenes with the corresponding 2-pyridyl reagents.