KF-Al2O3 Induced the Condensation of 2-Nitrofluorene and Para-Substituted Acetophenones with Aromatic Aldehydes

In the presence of KF-Al₂O₃ as a solid base, 2-nitrofluorene 1 condensed with aromatic aldehydes 2a-f in methanol to give 2-nitrodibenzo-fulvenes 3a-f in high yield. The para-substituted acetophenones 4a-f reacted with cinnamic aldehyde to give 1, 5-diaryl-2, 4-pentadien-1-ones 6a-f in moderate yield.     

Synthesis of Linearly Fused Tetracyclic Heterocycles Through a Novel Base Catalyzed Intramolecular Rearrangement Involving Scission of N-N Bond

Synthesis of s-triazolothiadiazepinoquinolines 4a-f and the base catalyzed intramolecular facile rearrangement of 4a-f to s-triazolothiazinoquinolines 5a-f involving scission of N-N bond is reported.     

Regiocontrolled Incorporation and Annulation of Glucose into Spirothiazole and Spirothiazoloxazole Derivatives

ABSTRACT

Cyclic ketones 1a-f reacted with mercaptoacetic acid in benzene and/or toluene in the presence of p-toluenesulfonic acid afforded the corresponding spiro-1,3-oxathialanone derivatives (2a-f). Compounds 2a-f reacted with glucosamine hydrochloride in a mixture of pyridine and ethanol to yield 3-(2′-glucosyl)-2-spiro[1′-cycloalkyl]thiazolidin-4-one derivatives 4a-f. Reaction of 4a-f with fused sodium acetate in a mixture of acetic anhydride and acetic acid gave annulated spirothiazoloxazologlucose derivatives 6a-f. All the synthesized spiro derivatives were identified by conventional methods (IR, ¹H NMR spectroscopy and elemental analyses).     

Synthesis of Azafluorenones using Zeolites.

A convenient method for the synthesis of various azafluorenones (2a-f & 4a-d) by cyclization of substituted arylpyridines (1a-f & 3a-d) using zeolites are described.     

Hypervalent Iodine in the Synthesis of Bridgehead Heterocycles: A New Synthesis of 3, 5-Diarylthiazolo[2, 3-C]-s-triazoles

The synthesis of 3, 5-diarylthiazolo{2, 3-c}-s-triazoles (3a-f) has been accomplished by using a new method involving oxidation of arenecarbaldehyde-4-arylthiazol-2-ylhydrazones (2a-f) with iodobenzene diacetate (IBD) in dichloromethane by intramolecular cyclization in high yields.     

Synthesis of Novel Spiro Tetrahydrothiapyrano-Isoxazolines and Pyrazolines

Cis 2,6-Diphenyltetrahydrothiapyranone (1) was subjected to Wittig reaction to generate exocyclic double bond (2a-c). Cycloaddition of nitrile oxides and nitrile imines to the latter led to a novel spiro tetrahydrothiapyranoisoxazolines (3a-f) and spiro tetrahydrothiapyranopyrazolines (4a-f)     

Reactivity of 4-bromomethylquinoline derivatives towards glycine and thioglycolic acid. A new ring system

Condensation of 4-bromomethylquinoline derivatives1 a-1 c with glycine and thioglycolic acid gave the corresponding quinolylmethylglycine and quinolylmethylthioacetic acid derivatives2 a-2 c and2 d-2 f, respectively. Cyclization of2 a-2 f was affected either by polyphosphoric acid or concentrated sulphuric acid to give3 a-3 f. Chlorination of2 a-2 f and3 a-3 f were also accomplished.

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Die Reaktivität von 4-Brommethylchinolin-Derivaten gegenüber Glycin und Thioglycolsäure. Ein neues Ringsystem

Zusammenfassung Die Reaktion von 4-Brommethylchinolin-Derivaten1 a-c mit Glycin und Thioglycolsäure gab die entsprechenden Kondensationsprodukte2 a-c und2d-f.2 a-f konnten mit Polyphosphorsäure bzw. mit konzentrierter Schwefelsäure zu Benzo[c]-2,6-naphthyridinen3 a-f zyklisiert werden.2 a-f und3 a-f waren einer Chlorierung (POCl₃) zugängig.

     

A Convenient and Improved Procedure for the Cyanation of Enamines and 1,3-Dicarbonyl Compounds

The direct cyanation of enamines 2a-f using acylsubstituted cyanatobenzenes 1a-c and cyanatoanthraquinone 1d furnishes β-cyanoenamines 3a-f which upon hydrolysis afford the cyanoketones 4a,b. 2-Cyano-1,3-diketones 6a-c are obtained starting from compounds 5a-c and 1.     

Zur Kenntnis der Reaktionsfähigkeit alkylsubstituierter Thiomorpholine, 1. Mitt.

Zusammenfassung Die Darstellung einigerMannichbasen (3 a-f) bzw.Mannich-basen-hydrochloride (2 a-f) und zahlreicher s-Triazin-Derivate (4 a-d, 5 a–m, 6 a–w, 7 a–e, 8 a–d, und9 a–l) auf Basis des unsubstituierten Thiomorpholins (1 a) sowie C-mono-[2-Methylthiomorpholin (1 b) und 2-Äthylthiomorpholin (1 c)] und C-dialkylierter Thiomorpholine [2-Methyl-3-äthylthiomorpholin (1 d)] wird beschrieben.

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Concomitant action of elementary sulfur and gaseous ammonia upon ketones, LXXIX: On the reactivity of alkyl substituted thiomorpholines, I

The preparation of someMannichbases (3 a-f) andMannich base hydrochlorides (2 a-f), resp., and numerous s-triazine derivatives (4 a-d, 5 a–m, 6 a–w, 7 a–e, 8 a–d, and9 a–l) based upon unsubstituted thiomorpholine (1 a) as well as C-mono-[2-methylthiomorpholine (1 b) and 2-ethylthio-morpholine (1 c)] and C-dialkylated thiomorpholines [2-methyl-3-ethylthiomorpholine (1 d)] is described.

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HerrE. Wilms dankt der Deutschen Texaco AG. für die Gewährung eines Stipendiums herzlichst.     

N,N-Dimethylamination of Acid Chlorides with Dmf

A solution of acid chlorides 3a-g in DMF solvent was refluxed to give N,N-dimethylamides 4a-f and 5g in excellent yields.     

Azo compounds and Schiff 's bases derived from 5-(4-pyridyl)-2-amino-1,3,4-thiadiazole: synthesis,mesomorphic properties and structural study by semi-empirical calculations

The synthesis and liquid crystalline properties of new Schiff 's bases (series 3a-f) and azo compounds (4a-f) incorporating pyridine and 1,3,4-thiadiazole rings are reported. The first homologues in the series of Schiff's bases (3a-c) show a monotropic mesophase and the homologues 3d-f display an enantiotropic SmA phase. The only azo compounds to exhibit liquid crystalline properties are the homologues 4e, f which show a monotropic nematic phase. These series are compared with Schiff's bases and azo compounds analogues (series 5 and 6), previously reported by us and an AM1 study of the structure/mesomorphic property relationship is described.     

A Facile Synthesis of 6-Substituted Benzimidazo[1,2-c]-Quinazolines Under Microwave Irradiation

Microwave irradiation promoted the high-yield cyclocondensation of ortho esters (1a-f) with 2-(2-aminophenyl)benzimidazole (2), as the catalyst was no longer needed.     

A Short Way to Esters of 1-Oxyl-2,2,5,5-Tetramethylpyrrolidine-3-carboxylic Acid by Favorski Rearrangement

The reaction of 3-bromo-4-oxo-l-oxyl-2,2,6,6-tetramethylpiperidine (1) with a solid sodium, alkoxide of primary or secondary alcohol provides a short way to prepare ester of 3-carboxy-1-oxyl-2,2,5,5-tetramethylpyrrolidine where the ring contraction from six (1) to five (6a-f) in a Favorski rearrangement occurs.     

Pseudoesters and Derivatives. XXXI1. Synthesis of 5-Ethylthio-, 5-Ethylsulfinyl- and 5-Ethylsulfonylfuran-2(5H)-ones

Convenient syntheses of 5-(ethylthio) furan-2(5H)-ones 2a-k from the appropriate 5-methoxyfuran-2(5H)-one 1a-g are described. The oxidation to the corresponding sulfoxides 5a-c and sulfones 6a-f is also reported.     

Phase Transfer Catalyzed Synthesis of Ferrocenoylcyclopropans

1-Phenyl-2-aryl-3-ferrocenoylcyclopropanes 3a-f have been prepared in moderate yield by the cycloaddition of the ylide generated in situ from triphenylbenzylarsonium bromide 2 to 1-oxo-3-aryl-2-propenylferrocenes 1a-d and 1,1'-di(-1-oxo-3-aryl-2-propenyl)ferrocenes le-f under phase transfer catalystic conditions.     

Tetralone Esters as Intermediates for the Synthesis of Podophyllotoxin Derivatives Via Cyclopropanation of Chalcones

Cyclopropyl ester (8a-f) were synthesized by the cyclopropanation of chalcones (7a-e) in dry benzene using powdered sodium in 80-85% yield. Preparation of tetralone ester (4a-e), an intermediate for the synthesis of podophyllotoxin derivatives by Lewis acid (SnCl₄) catalyzed cyclization of (8a-e) is also described here.     

Synthesen und ungewöhnliche Mesophasensequenzen von Kohlenwasserstoffen eines neuartigen Typs nicht-calamitischer Flüssigkristalle

Abstract

Mehrere Vertreter einer neuen Familie thermotroper, nicht-calamitischer Flüssigkristalle, die p-substituierten, biaxialen und zentrosymmetrischen 1,2,3,5,6,7-Hexakis(phenylethinyl)naphthaline 3a-f, wurden in einer Pd-kataly-sierten CC-Kupplungsreaktion aus dem entsprechenden Hexabromnaphthalin und verschiedenartig monosubstituiertem Acetylen (2a-f) synthetisiert. Diese Synthesemethode stellt ein vielversprechendes, ‘Lego-artiges’ Aufbauprinzip für Mesogene mit flächendeckenden, hoch ungesättigten und konjugierten π-Systemen als neuen Typ von ‘Super-disc-Kernen’ dar. Die stabilen Mesophasenbereiche von 3a-f reichen von c. 42 bis 180 K. Mit einer Ausnahme (3a) zeigen alle neuen Verbindungen eine stabile, fluide N_D-Phase. Während ein Kohlenwasserstoff dieser Serie (3e) sowie der Hexaether 3f nur eine Mesophase ausbilden, zeigen die vier Kohlenwasserstoffe 3a-d Multimesomorphismus mit einer inversen Phasen-sequenz (C → N_D → 2 D → I) bei den mittleren Homologen 3b-d. Beim schnellen Heizen der N_D-Phase des Kohlenwasserstoffs 3d ist kurzfristig eine instabile reentrant-isotrope Phase zu beobachten, die sich in eine columnare Mesophase umwandelt. der Vergleich der Kohlenwasserstoffe 3a-e mit dem Hexaether 3f läßt erstmals bei nicht-calamitischen Flüssigkristallen schlüssig einen elektronischen Effekt von Sauerstoffatomen, den Bindegliedern zwischen den leicht polarisierbaren ‘Super-disc-Kernen’ und den Lateralfunktionen, auf die Stabilität ihrer N_D-Phasen nachweisen. Sauerstoffatome in diesen Positionen stabilisieren die N_D-Phase, oder, mit anderen Worten, destabilisieren columnare Mesophasen.     

Über die Darstellung von substituierten 3,4-Dihydro-2(1H)-pyrimidin-iminen und 2-Aminopyrimidinen aus Guanidin und α,β-ungesättigten Ketonen

Guanidine reacts with the 2-alken-1-ones4 a-f and5 to give the unstable dihydropyrimidinimines (or-amines respectively)8 a-f (I, II or III respectively) and the hexahydroquinazolinimine (-amine)9 (I, II or III);8 a-f lose H₂, partly in the course of the reaction, partly during recrystallization to yield the 2-pyrimidinamines10 a-c, e, f, and the 4-methyl-5,6,7,8-tetrahydro-2-quinazolinamine11. With picric acid the unstable compounds8 d, f and9, resp. are converted into the stable 2-amino-3,4-dihydro-1H-2-pyrimidinylium picrates12 d and into the 2-amino-4-methyl-3,5,6,7,8,8 a-hexahydro-1H-2-quinazolinium picrate (13 resp.14, 15)¹⁸, whereas8 e reacts with HCl to give the chloride12 e. The structures of12 d-f follow from their NMR-spectra, and of10 a-c, e, f and11 by alternative syntheses by known methods^12–17 (e.g. from -diketones and guanidine). The reaction of8 d-f and9 to10 d-f and11 respectively is compared with previously described dehydrogenation and disproportionation reactions, especially of 3,4-dihydro-2(1H)-pyrimidinones (6 d ⁴,23 ²⁰) and-thiones (30 ¹) of similar structure and formulated as a base-catalysed elimination of H₂.

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HerrnA. Fuchsgruber danken wir für die Aufnahme und Hilfe bei der Interpretation der NMR-Spektren.     

A Convenient Synthesis of 3-Benzoylindolizine-5-carbaldehydes

3-Benzoylindolizine-5-carbaldehydes (4a-f), which could be used as derivatization reagents for amino compounds in HPCE were synthesized based on the 1,3-dipolar cycloaddition of 1-phenacyl-2-(1,3-dioxolan-2-yl)pyridinium ylide with alkenes in the presence of TPCD.     

New Biologically Active N-(Tetrahydrobenzothienopyrimidin-4-YL)-Amino Acids,Thiourethane, Sulfonamides and Related Compounds

Abstract

Some derivatives of thieno[2,3-d]pyrimidine containing amino acids 3a-i, imidazoles 4a-f, isothiocyanate 5, thiourethane 6, triazine 8, pyrimidine 10, sulphonamides 13a-d, 14, pyrazole 16 and pyrazolone 17 were synthesized. The structural assignments of the new compounds were based on analytical, spectroscopic measurements and chemical reactions. Some of the obtained compounds showed interesting antimicrobial activities.