Aziridinyl ketones. XVIII. The rearrangement-dehydrogenation of cis-1-cyclohexyl-2-phenyl-3-aroylaziridines

The sequential nature of the unique rearrangement-dehydrogenation of cis-1-alkyl-2-aryl-3-aroylaziridines ( 1a-d ) into 2-alkylamino-3-arylindenones ( 2a-d ) when treated with a lithium amide has been established. Furthermore, a competitive degradation pathway has been discovered which leads to ω-aminoacetophenones and benzaldehyde, thereby accounting for the major product of this reaction. trans-1-Alkyl-2-aryl-3-aroylaziridines do not react with the lithium amides employed in these studies. Although 1-cyclohexyl-2-methyl-3-benzoylaziridine reacts with lithium amide to produce a 3-carbanion, neither a rearrangement-dehydrogenation to a 2-aminoindenone nor a more extensive degradation involving carbon-carbon bond cleavage is observed. Mechanistic pathways for these base catalyzed reactions are discussed.     

Esters Synthesis by Addition of Monocarboxylic Acids to exo-5-Substituted Bicyclo[2.2.1]hept-2-ene Hydrocarbons

New alicyclic esters were synthesized by addition at heating of aliphatic monocarboxylic saturated acids C₁-C₄ to exo-5-phenyl-, exo-5-cyclohexyl-, and exo-5-(cyclohex-3-enyl)bicyclo[2.2.1]hept-2-enes. Among the esters obtained the acetates has more pleasant odor with fruit tint, and they may be used as a component of synthetic perfumes.     

Reaction of 1-alkyl-2-aryl-3-(2-methyl-2,3-epoxypropionyl)aziridines with boron trifluoride etherate in methanol

The reaction of boron trifluoride etherate in methanol with trans-1-methyl(ethyl)-or cis-1-cyclohexyl-2-aryl-3-(2-methyl-2,3-epoxypropionyl)aziridines leads to the formation of the corresponding boron fluoride complexes on the nitrogen atom of the aziridine ring. Reaction with trans-1-cyclohexyl-2-phenyl-3-(2-methyl-2,3-epoxypropionyl)aziridines occurs with stereospecific opening of the aziridine ring to give diastereomeric 2-methyl-5-methoxy-5-phenyl-4-cyclohexylamino-1,2-epoxypen-tan-3-ones, as well as products from the opening of the epoxide and aziridine rings — tetrahydrofuranones and tetrahydropyranones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 596–600, May, 1986.     

Aziridinyl ketones XVII. The hydrogenation of 2-phenyl-3-aroylaziridines to aziridinylcarbinols

The sodium borohydride reduction of both cis and trans-1-cyclohexyl-2-phenyl-3-aroylaziridines provides in each case the corresponding carbinol as a mixture of the two possible diastereoisomeric racemates, whereas reduction of these ketones with lithium aluminum hydride or with lithium diisopropylamide provides only the racemate resulting from attack on the carbonyl group from the least hindered side. Catalytic hydrogenation of a cis aziridinyl ketone cleaved the aziridine ring and provided an amino carbinol.     

Thermal decomposition of 2-amino-3-aziridino-1,4-naphthoquinones

The course of the thermal decomposition of various 2-amino-3-substituted aziridino-1,4-naphthoquinones (Ia-g) was investigated. In all the cases, the thermal decomposition gave variable amounts of 2,3-diamino-1,4-naphthoquinone (II) and of substituted 1,2,3,4,5,10-hexahydrobenzo[g]quinoxaline-5,10-diones (IIIa-g) with complete stereospecificity. The decomposition of the aziridines Ib,f also gave significative amounts of 2-amino-3-allylamino-1,4-naphthoquinones (IVb,f). In the case of 2-amino-3-(2′-phenyl-3′-ethylaziridino)-1,4-naphthoquinone (Ig), the formation of trans-1-phenyl-1-butene (V), 2-(1-phenylpropyl)-1H-naphtho-imidazole-4,9-dione (VI), 2-phenyl-3-ethyl-3,4,5,10-tetrahydrobenzo[g]quinoxaline-5,10-dione (VII), 2-phenyl-3-ethyl-5,10-dihydrobenzo[g]quinoxaline-5,10-dione (VIII), and a mixture of cis- and trans-4H-2,3,5,6-tetra-hydro-2-phenyl-3-ethyl-5-iminonaphtho[1,2-b]oxazin-6-one (IX) also occurred. Hypotheses concerning the mechanism and the steric course of this reaction are given. The reaction is a general method for the stereospecific synthesis of 2,3-disubstituted 1,2,3,4,5,10-hexahydrobenzo[g]quinoxalines.     

Synthesis of pyrrolidine and tetrahydroazonine derivatives from <Emphasis Type="Italic">N</Emphasis>-[bis(ethoxycarbonyl)methyl]tetrahydropyridinium bromide and methyl acetylenedicarboxylate

The reaction of N-methyl-N-(diethoxycarbonyl)methyltetrahydropyridinium bromide with dimethyl acetylenedicarboxylate in the presence of triethylamine at room temperature afforded 1,2-dimethyl 1-ethyl 2-[(3-vinyl-1-methyl-3-phenyl-2-ethoxycarbonyl)pyrrolidin-2-yl]-ethene-1,1,2-tricarboxylate in 25% yield. Its structure was proved by XRD analysis. At cooling to −20°C the pyrrolidine yield signifi cantly decreased and 3,4-dimethyl 2,2-diethyl 1-methyl-7-phenyl-1,5,8,9-tetrahydro-2H-azonine-2,2,3,4-tetratcarboxylate was obtained in 31% yield.     

Ringschlüsse an Chinonylmethanfarbstoffen und analogen Merocyaninen. 2. Mitteilung. Dihydronaphthophenazinone; Beeinflussung der Löslichkeitseigenschaften durch Substitution,Isolierung und Charakterisierung einer Zwischenstufe des Ringschlusses

Cyclization Reactions of Quinonylmethane Dyes and Analogous Merocyanines. 2. Communication: Dihydro-oxo-naphto-phenazines. Correlation of Solubility and Substitution. Isolation and Characterization of an Intermediate Compound An intermediate compound of the cyclization reaction of 2-chloro-3-(1-cyclohexyl-3-methyl-1,2-dihydroquinoxalin-2-ylidenmethyl)-naphthoquinone was isolated and characterized by spectroscopic methods. 6-Chloro-8-cyclohexyl-5,8-dihydronaphtho[1,2-b]phenazinone was obtained as the final product of this reaction. Several more dihydronaphtho[1,2-b]phenazinone dyes were synthesized. The relationship of substitution and solubility of the dyes is discussed. The visible and ¹H-NMR. and some mass spectra of the dyes are given.     

Synthesis of isocoumarin, 1-isoquinolone and 4(1H)-quinolone derivatives via seleno-intermediates

The reaction of 2-styrylbenzoic acids 2 with N-phenylselenosuccinimide (N-PSS) affords 3-phenyl-iso-coumarin derivatives 3 and 3,4-dihydro-3-phenyl-4-(phenylseleno)isocoumarins 4 via selenolactonization. The reaction of 2-styrylbenzamides 5 and 1-(2-aminophenyl)-3-phenyl-2-peropen-1-one derivatives 11 with N-PSS also resulted in the formation of 1-isoquinolone 6 and 4(1H)-quinolone derivatives 12 , respectively.     

Catalytic Potential of Pyrazolone Based Dioxidomolybdenum(VI) Complexes for Multicomponent Biginelli Reactions,Epoxidation of Olefins and Oxidative Bromination of Phenol Derivatives

Three different types of dioxidomolybdenum(VI) complexes of 4-acetyl-3-methyl-1-phenyl-5-pyrazolone (Hmp, I )), 3-methyl-1-phenyl-4-propionyl-5-pyrazolone (Hpp, II ), 4-butyryl-3-methyl-1-phenyl-5-pyrazolone (Hbutp, III ), and 4-isobutyryl-3-methyl-1-phenyl-5-pyrazolone (isobutp, IV ) have been isolated and characterized by various spectroscopic (FT-IR, UV/Vis, ¹H and ¹³C NMR) techniques, thermal analysis and single crystal X-ray analysis. These complexes adopt a distorted six-coordinate octahedral geometry where ligands act as bidentate, coordinating through the two O atoms. These complexes have been used as catalysts to explore a single pot multicomponent (benzaldehyde or its derivatives, urea/thiourea and ethyl acetoacetate/phenyl acetoacatate) Biginelli reaction producing biologically active 3,4-dihydropyrimidin-2-(1H)-one and 3,4-dihydropyrimidin-2-(1H)-thione based biomolecules under solvent-free conditions. Presence of H₂O₂ improves the yield of dihydropyrimidin-2-(1H)-one but it acts as poison for the later molecule. Epoxidation of internal and terminal alkenes mainly resulted in the formation of the corresponding epoxide. The catalytic oxidative bromination of thymol, a reaction facilitated by vanadium dependent haloperoxidases, resulted in the formation of three product namely 2-bromothymol, 4-bromothymol and 2,4-bromothymol. Other phenol derivatives have also been brominated effectively.     

Reaction of R-(+)-2-benzylideneaminobutan-1-ol with ethylene phosphorochloridite. Stereospecific formation of (3R,5R)-2-(2-chloroethoxy)-5-ethyl-2-oxo-3-phenyl-1,4,2-oxazaphosphorinane

The reaction of R-(+)-2-benzylideneaminobutan-1-ol with ethylene phosphorochloridite afforded phosphorus-epimeric (3R,5R)-2-(2-chloroethoxy)-5-ethyl-2-oxo-3-phenyl-1,4,2-oxazaphosphorinanes. The phosphorinane-ring closure proceeded stereospecifically and occurred only from one of the diastereofacial sides (re) of the C=N bond.     

Structural modifications in imide-aryl ether phenylquinoxaline random copolymers

A rigid rod polyimide derived from biphenyldianhydride (BPDA) and p-phenylenediamine (PDA) was modified by the incorporation of diamines containing performed phenylquinoxaline and aryl ether linkages, and the morphology and mechanical properties of the resulting imide-aryl ether phenylquinoxaline copolymers were investigated. These phenylquinoxaline containing diamines, 1, 4-bis[6-(3-aminophenoxy)-3-phenyl-2-quinoxalinyl] benzene and 1, 4-bis[6-(4-aminophenoxy)-3-phenyl-2-quinoxalinyl] benzene, were prepared by a novel nucleophilic aromatic substitution reaction of 1,4-(6-fluoro-3-phenyl-2-quinoxalinyl) benzene with either 1, 3- or 1, 4-aminophenol in the presence of K₂CO₃, respectively. The diamines were utilized as co-monomers with BPDA and PDA to synthesize poly(amicacids.) Films were cast and cured (350°C) to effect imidization, affording films which showed high elongations and moduli. The copolymers with high phenylquinoxaline compositions displayed T_g's in the 300°C range, and the thermal stability of the copolymers was comparable to that of the parent polyimide. The copolymers also showed improved auto- or self-adhesion, particularly those which showed a T_g, allowing sufficient molecular motion for interdiffusion.     

Synthesis and Reactions of 5-Amino-3-(3-methyl-5-oxo-1-phenyl-2-pyrazolin-4-yl)-7-phenyl-7 H -thiazolo[3,2- a ]pyrimidine-6-carbonitrile

5-Amino-3-(3-methyl-5-oxo-1-phenyl-2-pyrazolin-4-yl)-7-phenyl-7H-thiazolo[3,2-a]pyrimidine-6-carbonitrile was synthesized via the reaction of 4-(2-aminothiazol-4-yl)-3-methyl-1-phenyl-2-pyrazolin-5-one with benzylidene malononitrile and was then transformed to related fused heterocyclic systems. The antifungal and antibacterial studies revealed in some cases excellent biocidal properties.     

Synthesis and Reactions of 5-Amino-3-(3-methyl-5-oxo-1-phenyl-2-pyrazolin-4-yl)-7-phenyl-7<Emphasis Type="Italic">H</Emphasis>-thiazolo[3,2-<Emphasis Type="Italic">a</Emphasis>]pyrimidine-6-carbonitrile

Summary. 5-Amino-3-(3-methyl-5-oxo-1-phenyl-2-pyrazolin-4-yl)-7-phenyl-7H-thiazolo[3,2-a]pyrimidine-6-carbonitrile was synthesized via the reaction of 4-(2-aminothiazol-4-yl)-3-methyl-1-phenyl-2-pyrazolin-5-one with benzylidene malononitrile and was then transformed to related fused heterocyclic systems. The antifungal and antibacterial studies revealed in some cases excellent biocidal properties.     

Synthesis and structure determination of isomeric 7- and 8-chloro-1,5-benzodiazepine derivatives

Reaction of 4-chloro-1,2-benzenediamine with 3,3-dimercapto-1-phenyl-2-propen-1-one afforded, as expected, a mixture of 7-chloro and 8-chloro-1,3-dihydro-4-phenyl-2H-1,5-benzodiazepine-2-thione. After separation of the two components and further reaction, their structure was established by chemical degradation of 7-chloro-2-(2-diethylaminoethylthio)-4-phenyl-3H-1,5-benzodiazepine to 5-chloro-1,3-dihydro-1-methyl-2H-benzimidazol-2-one. The structure was also confirmed by single X-ray analysis of 7-chloro-2-(2-diethylaminoethylthio)-4-phenyl-3H-1,5-benzodiazepine.     

The structure of the diazonium coupling products of phenacyl thiocyanate and phenacyl selenocyanate with diazotized 3-phenyl-5-aminopyrazole

The reaction of diazotized 3-phenyl-5-aminopyrazole with phenacyl thiocyanate 1a and phenacyl selenocyanate 1b afforded directly 2-imino-3-(3-phenyl-5-pyrazolyl)-5-benzoyl-2,3-dihydro-1,3,4-thiadiazole monohydrate 9a and 2-imino-3-(3-phenyl-5-pyrazolyl)-5-benzoyl-2,3-dihydro-1,3,4-selenadiazole monohydrate 9b , respectively. The products 9a and 9b were also obtained from the reaction of C-benzoyl-N-(3-phenyl-5-pyrazolyl)formohydrazidoyl bromide 10 with potassium thiocyanate and potassium selenocyanate, respectively. Acetylation, benzoylation, and nitrosation of 9 afforded the corresponding diacetyl, dibenzoyl, and nitroso derivatives 11-13 , respectively. Cyclization of C-benzoyl-N-(3-phenyl-5-pyrazolyl)-nitrilimine 6 was shown to give the pyrazolo [5,1-d]triazole 8 and not the pyrazolo[5,1-c]-as-triazine derivative 7 , as previously reported.     

Ringschlüsse an Chinonylmethanfarbstoffen und analogen Merocyaninen. 6. Mitteilung. Über die Reaktivität des Cyclohexylrestes in 2-Chlor-3-[(1-cyclohexyl-6-fluor-3-methyl-1H-chinoxalin-2-yliden)methyl]-1,4-naphthochinon

Ring Closure in Quinonylmethane Dyes On the Reactivity of the Cyciohexyl Moiety in 2-Chloro-3-[(1-cyclohexyl-6-fluoro-3-methyl-1H-quinoxalin-2-ylidene)niethyl]-1,4-naphthoquinonc The reactive title compound ( 1a , X = F , R ¹ = C⁶H¹¹, R ²=Cl) was obtained from the reaction of 1-cyclohexyl-6-fluoro-2,3-dimethylquinoxalinium perchlorate with 2,3-dichloro-1,4-naphthoquinone. Upon treatment with pyridine and acetic acid in acetone and separation of the desired naphthophenazinone 2a , an unexpected azepinoquinoxaline 4a was isolated. The structure of 4a was determined by its mass and 360-MHz-¹H-NMR. spectra in connection with decoupling experiments.     

Reaction of 3-hetero-substituted 2-phenyl-4-thioxo-3,4-dihydro-quinazolines with acyl chlorides and phenacyl bromides

Some 2, 5-disubstituted 1, 3, 4-thiadiazoles 5 were obtained by reaction of 3-amino-2-phenyl-4-thioxo-3, 4-dihydroquinazoline ( 1 ) with acyl chlorides. Reaction of 3-hydroxy-2-phenyl-3, 4-dihydroquinazoline ( 3 ) with phenacyl bromides was carried out either in dry acetonitrile or dimethylformamide to give 2-phenyl-4-phenacylthio-3-quinazolinium N-oxides 7 or 2-phenyl-4-phenacylidene-1H-3-quinazolinium N-oxides' 8 , respectively.     

Cinnoline chemistry. XIV. 3-cyclohexylcinnolines

The synthesis of 3-cyclohexyl-6,7-dimethoxy-1H-4-cinnolone ( 4 ), 4-chloro-3-cyclohexyl-6,7-dimethoxycinnoline ( 5 ) and 8-bromo-3-cyclohexyl-6,7-dimethoxy-1H-4-cinnolone ( 6 ) are reported.     

Oxidation and photochemical reactions of 3-phenyl-2H-1,4-benzoxazines

3-Phenyl-2H-1, 4-benzoxazines 4-oxides are light sensitive compounds, irradiation leads to 3-phenyl-2H-1,4-benoxazines and to their 3-oxidized derivatives, whenever possible. Intermediate oxaziridines are formed during the photolysis and transformed into stable nitroxide radicals. The structure of these radicals was confirmed through peracid oxidation of 3-phenyl-2H-1,4-benzoxazines and 3-phenyl-3, 4-dihydro-2H-1,4-benzoxazines. A reaction mechanism is proposed on the basis of experimental observations.     

1,3-Dipolare Cycloadditionen von 2-(Benzonitrilio)-2-propanid mit 4,4-Dimethyl-2-phenyl-2-thiazolin-5-thion und Schwefelkohlenstoff

1,3-Dipolar Cycloadditions of 2-(Benzonitrilio)-2-propanide with 4,4-Dimethyl-2-phenyl-2-thiazolin-5-thione and Carbon Disulfide Irradiation of 2,2-dimethyl-3-phenyl-2H-azirine ( 11 ) in the presence of 4,4-dimethyl-2-phenyl-2-thiazolin-5-thione ( 7 ) yields a mixture of the three (1:1)-ad-ducts 8 , 12 and 13 (Schemes 3 and 6). The formation of 8 and 12 can be explained by 1,3-dipolar cycloaddition of 2-(benzonitrilio)-2-propanide ( 1b ) to the C, S-double bond of 7. Photochemical isomerization of 12 leads to the third isomer 13 (Schemes 3 and 7). Photolysis of the azirine 11 in the presence of carbon disulfide gives a mixture of two (2:l)-adducts, namely 12 and 13 (Scheme 4). A reaction mechanism via the intermediate formation of the 3-thiazolin-5-thione b is postulated. The structure of the heterocyclic spiro compound 13 has been established by single-crystal X-ray structure determination (cf. Fig. 1 and 2).