Quinoline syntheses by reaction of hydrazoic acid with α,β-disubstituted cis-chalcones

Hydrazoic-sulfuric acid mixture converted cis-α-phenyl-β-benzoylchalcone (trans-dibenzoylstilbene, 4 ) into 2,3-diphenyl-4-benzoylquinoline ( 5 ) the structure of which was proved by debenzoylation to 2,3-diphenylquinoline. α,β-Diphenyl and cis-α,β-dibromochalcones similarly were converted respectively into 2,3,4-triphenylquinoline ( 19 ) and 2-phenyl-3,4-dibromoquinoline ( 20 ). The structure of 19 was shown by difference from the corresponding isoquinoline 21 (synthesized). Smith's mechanism for the analogous conversion of o-phenylbenzophenone into 9-phenylphenanthridine through the 9-fluorenol and the 9-hydroazide with loss of nitrogen and ring expansion, was supported by methyl label experiments using 2-(p-tolyl)benzophenone which gave a 53:47 mixture of 3- and 8-methyl-6-phenylphenanthridines. Applicability of the mechanism to the reactions with disubstituted cis-chalcones was shown by sulfuric acid conversions of two of these into indenol 22 and 2-bromo-3-phenylindenone ( 24 ), respectively. trans-Dibenzoylstilbene underwent resinification in sulfuric acid, giving the quinoline ( 5 ) only when hydrazoic acid was present.     

Anil-Synthese. 20. Mitteilung. Über die Herstellung von Stilbenyl-Derivaten des 1,2,4,-Oxadiazols

Preparation of Stilbenyl Derivatives of 1,2,4-Oxadiazoles Schiffs bases derived from 3- and 5-(p-formylphenyl)-phenyl-1,2,4-oxadiazoles and chloroanilines are reacted with various p-tolyl substituted aromatic heterocycles in the presence of dimethylformamide and potassium hydroxide to yield the corresponding heterocyclic substituted stilbenes (‘Anil synthesis’). The reactivity of 5-[4-(chlorophenylimino-methyl)phenyl]-3-phenyl-1,2,4-oxadiazoles is very low and side reactions will predominate.     

Photochemische Cycloadditionen von 3-phenyl-2h-azirinen mit Aldehyden. 31. Mitteilung über Photoreaktionen

Experiments concerning the photochemical condensation of 3-phenyl-2H-azirines 1 with aliphatic and aromatic aldehydes to 3-oxazolines 4 are fully described (cf. scheme 1 ). Photochemically nitrile methylides of type 2 are first formed, which then very quickly react thermally with the aldehydes in a regiospecific manner to give the 3-oxazolines 4 . Azirines monosubstituted in position 2 (l b and 1 c ) give mixtures of cis, trans-oxazoline isomers, in which the cis isomer predominates. The stereoselectivity of the cycloaddition reaction can be rationalized by a simple model (scheme 10). The stereoisomeric 3-oxazolines 4 are distinguishable in the NMR. spectra by the large homoallylic coupling constants between the H atoms on C(2) and C(5).     

Ringschlussreaktionen mit 2-(β-Styryl)benzylaminen 5-Phenyl-1H-2-benzazepine. 23. Mitteilung über siebengliedrige Heterocyclen

Cyclization reactions with 2-(β-styryl)benzylamines 5-Phenyl-1H-2-benzazepines Cyclization of the urea derivative 3 with POCl₃ to give 2-(4-methyl-1-piperazinyl)-4-phenylquinoline ( 4 ) was carried out in analogy to the quinoline synthesis of Foulds & Robinson. This reaction was used for the preparation of 2-benzazepines. The trisubstituted ureas 6 and 8 , derived from the 2-(β-styryl)-benzylamines 5 , were cyclized with POCl₃ to yield the 3-amino-5-phenyl-1H-2-benzazepines 7 and 9 , respectively. Similarly, cyclization of the corresponding acetyl-derivatives 10 gave the 3-methyl-5-phenyl-1H-2-benzazepines 12 . On the other hand, the disubstituted urea 15 , cyclized under the same conditions to the 1-methyl-1-phenylisoindoline derivative 16 , and 2-(β-styryl)benzylamine ( 5a ) on treatment with phosgene gave the isoindoline 17 in an analogous manner.     

The electron-impact induced fragmentation of substituted 4-styrylquinolines

The fragmentation of 4-styrylquinoline (I), 4-(p-nitrostyryl)-quinoline (II), 4-(p-chlorostyryl)-quinoline (III), 4-(p-hydroxystyryl)-quinoline (IV), 4-(p-methoxystyryl)-quinoline (V), 4-(p-dimethylaminostyryl)-quinoline (VI) and 4-(p-cyanostyryl)-quinoline (VII) under electron-impact in the mass spectrometer is reported. The role and the influence of substituents on the fragmentation scheme is discussed. The loss of the substituents from the molecular ion is correlated with LCAOMO quantities.     

Photochemische Synthesen potentiell hypoglykämisch wirkender 3-Oxazoline

Photochemical Syntheses of 3-Oxazolines which Possibly Exhibit Hypoglycemic Activity Reactions of photochemically generated benzonitrile methylides 2 with carbonyl compounds 3 yielded 3-oxazolines of the types 5 and 6 (Scheme 1). Photooxidation of 5-[p-(dimethylamino)phenyl]-2,2-dimethyl-4-phenyl-3-oxazoline ( 5a ) gave 4′-(2,2-dimethyl-4-phenyl-3-oxazolin-5-yl)-N-methylformanilide ( 6r ) which could be transformed to 2,2-dimethyl-5-[p-(methylamino)phenyl]-4-phenyl-3-oxazoline ( 6s ) by photodecarbonylation. Thirty 3-oxazolines of types 5 and 6 have been synthesized and tested by oral and/or intraperitoneal administration to starved rats and obese-hyperglycemic mice.     

Study of two diastereomeric pairs of regiosomeric 2-isoxazolines by tandem mass spectrometry with electron impact ionization

On electron impact (EI) ionization, two cis/trans pairs of 4-methyl-5-phenyl and 4-phenyl-5-methyl regioisomeric 3-carbethoxy-2-isoxazolines showed normal mass spectra and mass-analysed ion kinetic energy (MIKE) spectra of metastable (MI) and collision-activated (CA) molecule ions, allowing unequivocal differentiation of the regioisomers. The cis/trans stereoisomers of each regioisomer showed very similar normal mass spectra. Very interestingly, the cis- and trans-4-phenyl-5-methyl stereoisomers appeared reasonably differentiated by the molecule ion MIKE spectra, whereas the 4-methyl-5-phenyl regioisomeric pair of stereoisomers did not. The influence of the phenyl substituent to the fragmentation processes was notable. Some fragments of interest were studied by comparison of their MIKE spectra with those of model ions, generated by EI from suitable substrates, including (i) the isomeric α,β-unsaturated oxime, namely ethyl (Z)-2-(hydroxymino)-3-methyl-4-phenylbut-3-enoate, a by-product of importance for the mechanism(s) of the addition/cycloaddition reactions of nitrile oxides to alkenes and (ii) trans-β-methylstyrene, a dipolarophilic reactant in the same reactions. The favoured heterocyclic C(5)–O(1) bond cleavage occurred only for the ionized 4-methyl-5-phenyl 2-isoxazoline pair, leading to a distonic ion of relevance, as it can represent either a reasonable precursor for both the isomerization to the ionized α,β-unsaturated oxime and the EI-induced cycloreversion yielding ionized β-methylstyrene, or the ionized form of a zwitterionic intermediate, which had been proposed previously for the addition/cycloaddition mechanism(s) in the solution phase, currently under study.     

Studies on quinones. XII. Cycloketalization of michael adducts from hydroxyquinones

The reaction of 2-hydroxy-3-(1-phenyl-3-oxobutyl)-1,4-naphthoquinone ( 1 ) with either acidic methanol or a mixture of trimethyl orthoformate, methanol and ammonium chloride resulted in the formation of the p-quinonic cycloketals: trans- and cis-4-phenyl-2-methyl-2-methoxy-3,4-dihydro-2H-naphtho[2,3-b]pyran-5,10-dione ( 2a,2b ). Cyclization of the Michael adducts 6, 10 and 11 , which are structurally related to 1 , with trimethyl orthoformate-methanol-ammonium chloride gave the corresponding p-quinonic cycloketals 7, 12 and 13 . The structures of the regioisomers 2a and 2b are proposed based on the spectral properties of compound 7 and by analysis of its proton nmr spectra.     

Propellanes. Part LXXVIII. Preparation of Several Triaza[3.3.3]propellanes and an Oxadiaza[3.3.3]propellane

3,7,10-Tribenzyl-3,7,10-triaza[3.3.3]propellane ( 4a ), 3,7-dibenzyl-10-phenyl-3,7,10-triaza[3.3.3]propellane ( 4c ), 3,7-dibenzyl-10-(p-tolyl)-3,7,10-triaza[3.3.3]propellane ( 4b ), and 3-oxa-7,10-diaza[3.3.3]propellane ( 6 ) have been prepared.     

11. Anil-Synthese. 16. Mitteilung. Über die Herstellung von styryl-derivaten des 2-phenyl-imidazo [1,2-a]pyridins

Preparation of styryl derivatives of 2-phenyl-imidazo [1, 2-a]pyridine 2-(p-Tolyl)-imidazo [1, 2-a]pyridines and 7-methyl-2-phenyl-imidazo [1,2-a]-pyridines can be converted, in dimethylformamide, on reaction with anils of aromatic aldehydes in the presence of potassium hydroxide or potassium t-butoxide, into the corresponding 2-(stilben-4-yl)- and 2-phenyl-7-styry1-imidazo [1, 2-a]-pyridines (‘Anil-Synthesis’). The 2-(p-tolyl)-imidazo [1,2-a]pyridines react far less readily than the 7-methyl-2-phenyl-imidazo[1,2-a]pyridines.     

Palladium-catalyzed vinylation of cyclohexenes using a directing-group strategy

Palladium-promoted vinylation of cyclohexenes via employment of a directing-group strategy to yield the coupled vinyl cyclohexenes with excellent regio- and stereoselectivity was studied. Typically, reaction of 2-(cyclohex-2-en-1-yl)-N-tosylacetamide ( 1a ) with (Z)-styryl bromides ( 2 ) gave cis-2-[(E)-styryl]cyclopent-3-en-1-yl-N-tosylacetamides in good to excellent yields. It is noticed that (Z)-styryl moiety was inverted into (E)-form in products. Unfortunately, (E)-styryl bromide substrates were not suitable for this reaction under the condition investigated. Further studies on norbornene system, we found that palladium-catalyzed reaction of endo-N-tosylbicyclo[2.2.1]hept-5-ene-2-carboxamide ( 6 ) with styryl bromides gave the Aza-Heck type products.     

Photochemistry of 3-aryl-2-isoxazoline1

3-Phenyl-2-isoxazoline (1) was irradiated to give 4-phenyl-2-oxazoline (3), β-aminoaldehyde (14) and benzonitrile from its π-π^* singlet excited state. Several related derivatives afforded similar photoproducts on irradiation. The quantum yields of the photoreactions were dependent on the magnitudes of the singlet energies of the 2-isoxazolines. p-Cyanophenyl-2-isoxazoline (1c) formed a one-to-one photoadduct (22) with benzene.     

Reductive Activation of Arenes: XVI. Anionic Products from Reduction of p-Tolunitrile with Sodium in Liquid Ammonia and Their Reaction with Butyl Bromide

Study of oxidation, protonation, and alkylation of the products obtained by one- and two-electron reduction of p-tolunitrile with sodium in liquid ammonia showed that these products are, respectively, p-tolunitrile radical anion and 1-cyano-4-methyl-2,5-cyclohexadienyl anion. The latter is formed by protonation of p-tolunitrile dianion with ammonia. The two-electron reduction involves protonation of p-tolunitrile dianion with initial p-tolunitrile, which gives rise to 4-cyanobenzyl anion. The yield of the latter depends on the order of mixing of the reactants. The anionic reduction products react with butyl bromide to afford products corresponding to ipso alkylation with respect to the cyano group, 4-butyltoluene and 3-butyl-3-cyano-6-methyl-1,4-cyclohexadiene, as well as the alkylation product at the benzylic position, 4-pentylbenzonitrile. The formation of 4-butyltoluene indicates the possibility for selective synthesis of p-alkyltoluenes by reductive alkylation of p-tolunitrile.     

Photoreaktionen von 5-Phenyl-pyrazolinen. Vorläufige Mitteilung

On irradiation in benzene 1-methyl-5-phenyl-Δ²-pyrazoline ( 1 ) is partly converted into trans- and cis-1-methylazo-2-phenyl-cyclopropanes ( 2 and 3 ) in the ratio of 23:77. Both 2 and 3 on thermal treatment are reconverted to 1 . A concurrent thermal equilibration of 2 and 3 is also observed. 1, 3-Dimethyl-5-phenyl-Δ²-pyrazoline ( 5 ) on irradiation in benzene yields the corresponding trans- and cis-1-methylazo-1-methyl-2-phenyl-cyclopropanes ( 6 and 7 ). In contrast similar treatment of 5-phenyl-Δ²-pyrazoline gives benz- and cinnamaldazine ( 9 and 11 ) along with the corresponding mixed aldazine ( 10 ).     

Reactions of styryl and phenylethynyl sulfones with some CH-acids

Reactions of methyl and p-tolyl phenylethynyl sulfones with enolated of dimethyl malonate and malononitrile lead to the formation of sulfonyl-substituted derivatives of ethylidenemalonic acid. Methyl (E)-β-styryl sulfone reacts with sodium enolates of dimethyl malonate, malononitrile, and methyl cyanoacetate to give common Michael adducts.     

Synthesis of functionally substituted isoxazole and isothiazole derivatives

Acylation of benzene and toluene with 5-phenyl- and 5-(p-tolyl)isoxazole-3-carbonyl chlorides gave 5-phenyl(or p-tolyl)isoxazol-3-yl phenyl(or p-tolyl)ketones which were reduced to the corresponding alcohols with sodium tetrahydridoborate in propan-2-ol. Selective reduction of the carboxy group in 4,5-dichloroisothiazole-3-carboxylic acid was achieved by the action of BH₃, and the aldehyde group in 4-formyl-2-methoxyphenyl 5-arylisoxazole-3-carboxylates and 4,5-dichloroisothiazole-3-carboxylates was reduced to hydroxymethyl group with sodium triacetoxyhydridoborate in benzene. Acylation of the resulting hydroxymethyl derivatives with 5-arylisoxazole- and 4,5-dichloroisothiazole-3-carbonyl chlorides afforded the corresponding esters containing two azole fragments in their molecules.     

Synthesis,polymerization, and copolymerization of lactam-substituted styrenes

Four new substituted styrene derivatives carrying lactam rings (2-pyrrolidone or 2-piperidone) in para position have been synthesized, namely 4-(2-oxo-3-methylene-pyrrolidinyl)styrene, 4-(2-oxo-3-methylene-piperidinyl)styrene, 4-(p-styryl)-2-pyrrolidone, and 4-(p-styryl)-2-piperidone. Their homopolymerization and copolymerization with styrene, methyl methacrylate, and acrylic acid have been considered. By ring opening of the side lactam groups, the homopolymers are transformed into the corresponding poly aminocarboxylic acids.     

Studies on DNA binding behavior of biologically active Cu(II) complexes of Schiff bases containing acyl pyrazolones and 2-ethanolamine

Pyrazolone derivatives (Z)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one [PMP-EA] (1), (Z)-1-(3-chlorophenyl)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1H-pyrazol-5(4H)-one [MCPMP-EA] (2), and (Z)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1-p-tolyl-1H-pyrazol-5(4H)-one [PTPMP-EA] (3) have been synthesized and characterized. The molecular geometry of 2 has been determined by single-crystal X-ray study. These ligands exist in amine-one tautomeric form in the solid state. Three copper(II) complexes, [Cu(PMP-EA)(H₂O)₂] (4), [Cu(MCPMP-EA)(H₂O)₂] (5), and [Cu(PTPMP-EA)(H₂O)₂] (6), respectively, have been synthesized using these ligands and characterized by microanalytical data, molar conductivity, IR, UV–Visible, FAB-Mass, magnetic measurement, TG-DTA studies, and ESR spectral studies; Cu(II) is five-coordinated with [ML(H₂O)₂] composition. The interaction of the complexes with CT-DNA (calfthymus) was investigated using different methods. The results suggest that the copper complexes bind to DNA via intercalation and can quench the fluorescence intensity of EB bound to DNA.     

Azimine. VI. 1-Alkoxycarbony 1-2,3-dialkyl- und -2,3-diaryl-azimine

Azimines VI: 1-Alkoxycarbonyl-2,3-dialkyl- and -2,3-diarylazimines Alkoxycarbonyl-nitrenes 2 – generated in situ by α-elimination from N-[(4-nitrophenyl)-sulfonyloxy]carbamates 4 – were reacted with six aliphatic and aromatic azo compounds to yield 1-alkoxycarbonyl-azimines 11 (R′ = Alkyl). Thus, (2Z)- or (2E)- 1 -alkoxycarbonyl-2,3-diisopropyl-azimines ( 8 or 9 ) were obtained stereospecifically from (E)- or (Z)-1,1′-dimethylazoethane ( 5 or 6 ) and 1-alkoxycarbonyl -2,3-(cis-1,3-cyclopentylene)-azimines ( 10 ) resulted from 2,3-diazabicyclo[2.2.1]-2-heptene ( 7 ), always using both ethoxy- and methoxycarbonyl-nitrene ( 2a and 2b ). With 2a , (E)-azobenzene ( 14 ) was converted only to a single stereoisomer of 1-ethoxycarbonyl-2,3-diphenyl-azimine ( 17 ) and both stereoisomers of azo(p-toluene) ( 15 or 16 ) reacted to give the same stereoisomer of 1-ethoxycarbonyl-2,3-di(p-tolyl)-azimine ( 18 ).     

Electrocyclic reactions of tetraenes: Influence of terminal substituents

Conjugated tetraenes with both central double bonds of cis configuration undergo a series of thermal reactions, the observable products being markedly dependent on the nature of the terminal substituents. Dimethyl 2E,4Z,6Z,8E-decatetraene-1,10-dioate (16) was prepared and found to cyclize readily at 50° to trans dimethyl 2,4-bicyclo[4.2.0)octadiene-6,7-dicarboxylate (18). This reaction proceeds to equilibrium, and the rates and equilibrium constants at the indicated temperatures are: 3.0 × 10^-5 sec^-1 ?40°; 8.2 × 10^-5 sec^-1, 16.0,50°; ?10.0,75°; ?7.47,100° with the equilibrium favoring (18). A sample of 1,8-diphenyl-1E,3Z,5Z;7E-octatetraene (1) showed no reaction below 120°, and at 175° all trans 1,8-diphenyl-octatetraene, cis and trans stilbenes, trans-5-phenyl-6(cis-styryl)-1,3-cyclohexadiene cis-5-phenyl-6-(trans-styryl)-1,3-cyclohexadiene, and cis and trans 6,8-diphenyl-tricyclo[3.2.1.0^2.7]oct-3-enes were formed. At 100° in the presence of excess dimethyl acetylenedicarboxylate 1 gave dimethyl trans-3,4-diphenyltricyclo[4.2.2.0^2.5]deca-6,9-dien-6,7-dicarboxylate. Finally 1,4-di(1-cyclohexen-1-yl)-1,3-batadiyne, hydrogenated over a Lindlar catalyst, gave only tricyclo[10.4.0.0^6,11]hexadeca-1,3,5-triene.