Orthoamide. LI. Push-Pull-Butadiene und Heterocyclen aus CH2-aciden Verbindungen und Orthoamiden von Alkincarbonsäuren

Orthoamides. LI. Push-Pull-Butadienes and Heterocycles from Alkyne Carboxylic Acid Orthoamides and CH₂-acidic Compounds The acetylides 4b, 4f react with N,N,N′,N′,N″,N″-hexamethylguanidiniumchloride ( 5 ) to give the orthoamides 6b, 6f , resp. From CH₂-acidic compounds and the orthoamides 6a, c, e can be obtained the push-pull-substituted butadienes 8a–8aj . The 2,3,5-trimethyl-thiadiazolium salt 9 does not condense with 6e , as other CH₂-acidic compounds do, instead the vinylogous guanidinium salt 10a is produced. On heating, the ketenaminals 8d, aa cyclize to give the pyridone-carbonitriles 11a, b , resp. From 4-amino-coumarins 12 and the orthocarboxylic acid amideacetals 13a, b and the ketenaminal 16 resp., the amidines 14a–c and the heterocyclic compounds 15a–c resp., are formed. The enamines 17a–c, 19a, b react with the orthoamides 6a–f to give the pyridine derivatives 18a–1, 20a–h and 21a, b , resp. Analogously, from 6-aminouracil 22 and 6a, b, e, f are formed the pure 7-dimethylaminopyrido[2,3-d] pyrimidines 23a, b or mixtures of compounds 23c, d and the isomeric 4-dimethylamino-pyrido[2,3-d]pyrimidines 24a, b resp., which can be separated via their salts 25a,b/26a,b . The heterocyclic compounds 30a–d, 32a,b can be prepared from the pyrazole derivatives 28, 31 resp. and the orthoamides 6a–f .     

Synthese und Reaktionen von 1,3-Azaphosphorinan-2-thionen

Synthesis and Reactions of 1,3-Azaphosphorinane-2-thiones Aminopropylphosphines, R P(H) (CH₂)₃ NH₂, react with carbon disulfide to give 1,3-azaphosphorinane-2-thiones. In presence of strong bases the title compounds are converted by alkyl halides into 2-alkylthio-3, 4, 5, 6-tetrahydro-1, 3-azaphosphorines whereas in absence of bases quaternization at the phosphorus atom occurs to give 2-thiono -1,3-azaphosphorinanium salts. The structures of the compounds prepared are elucidated by IR. ¹H-n.m.r. and mass spectra.     

Strukturaufklärung von ausgewählten nitro- und sulfonsäuresubstituierten 1,2-Naphthochinon-2-diaziden

Structure Determination of Selected Nitro and Sulfonic Acid Substituted 1,2-Naphthoquinone-2-diazides Selected nitro derivatives of 1,2-naphtoquinone-2-diazide 2 and 5 have been synthesized, the position of the NO₂-group has been unambigously determined by means of ¹H and ¹³C n.m.r. spectroscopy, and the structure of these compounds has been comprehensively determined in relation to unsubstituted 1 and sulfonic acid substituted derivatives 3 , 3a , 4 and 4a . Furthermore, the spectroscopical behaviour, especially in the uv/vis region, was examined in correlation to quantum chemical calculations.     

Synthese substituierter 2-Aminochinolin-1-oxide durch reduktive Cyclisierung substituierter 3-(2-Nitrophenyl)acrylnitrile

Synthesis of Substituted 2-Aminoquinoline-1-oxides by Reductive Cyclization of Substituted 3-(2-Nitrophenyl)acrylonitriles An approach to the class of 2-aminoquinoline-1-oxides is given based on reductive cyclization of appropriate substituted 3-(2-nitrophenyl)acrylonitriles. Thus, 2-nitrobenzylidene compounds 1 a – d have been reductively cyclized by H₂/PtO₂ or H₂/Pd-C under normal conditions to form N-oxides 2 a – d . ¹H-NMR data show that 1 d has to be regarded as ethyl(Z)-2-cyano-3-hydroxy-3(2-nitrophenyl)acrylate. The analogous (2-nitrobenzoyl)acetonitrile 3 , however, did not cyclize under the same conditions, but yielded anthraniloylacetonitrile 4 . The results are discussed in comparison with the reaction behaviour of structural related nitronitriles under comparable conditions. A short survey of reactions leading to heterocyclic N-oxides by reductive cyclization of nitro compounds is given.     

Katalytische Spaltung substituierter 1,3-Dioxane

Catalytic Cleavage of Substituted 1,3-Dioxane The catalytic cleavage of 4-phenyl-1,3-dioxane and 4-methyl-4-phenyl-1,3-dioxane using palladium or CuO Cr₂O₃ BaCrO₄ catalysts was studied in this work. The hydrogenolysis of cited 1,3-dioxanes using CuO Cr₂O₃ BaCrO₄ catalyst gives 3-phenyl-1-propanole and 3-phenyl-1-butanole, resp. in high yields. It is possible to obtain these primary alcohols also by pressureless cleavage using the palladium catalysts in a hydrogen atmosphere. The cleavage of 4-phenyl-1,3-dioxane in the inert atmosphere produced propiophenone selectivelly. The byproducts of the reactions were identified and the reaction scheme of the catalytic cleavage is suggested.     

Ein einfacher Weg zur Herstellung chlorsubstituierter Arylazobenzen-, Arylazonaphthalen- und Arylazopyrazol-Derivate

A Simple Route for the Synthesis of Chlorosubstituted Arylazobenzenes, Arylazonaphthalenes, and Arylazopyrazoles The reaction of arylazophenoles and arylazohydroxypyrazoles (or their tautomer hydrazones) 10, 11 , and 15 with POCl₃ in dimethylformamide yields chlorosubstituted arylazobenzenes or arylazopyrazoles 12, 13 , and 16 , resp., in moderate to high yields. The substitution of the OH-group by the Cl-moiety is favoured by acceptor substituents in the aryl fragments ortho- and/or para-linked to the azo group. In case that arylazocompounds derived from resorcinol are used the substitution reaction runs in a stepwise manner giving raise to the formation of o-hydroxy-p-chlorosubstituted azo compounds 18 primarily and then of dichlorosubstituted azo compounds 19 .     

Stereochemische Gesichtspunkte zu der Reaktion zwischen Cyclohexylidenacetaldehyden und Mercaptanen

Some Stereochemical Aspects of the Reaction between Cyclohexylidene Acetaldehydes and Thiols The reaction between cyclohexylidene acetaldehyde, 4-methyl-cyclohexylidene acetaldehyde resp. 4-tert.-butylcyclohexylidene acetaldehyde and thioglycolic acid thioglycolic acid methylester, benzylthiol resp. isopropylthiol and catalytical amounts of conc. HCl gave 60% cyclohexylidene acetaldehyde dimercaptales 1 – 3 . In addition to these compounds i t was also obtained in 40% a mixture of 46% cis and 54% trans forms of the cyclohexane derivatives 4–9. Double magnetic non equivalent methylenic protons were found in the compounds 2a – 2c and 3a – 3c and double magnetic non equivalent geminal methyl groups in the compounds 2d and 3d . ⁴J_H,H couplings were observed in 1–3. The reaction mechanisms of the formation of the compounds 4–9 as well as the ¹H-n.m.r. spectra of the compounds 1–9 were discussed.     

1H- und 13C -NMR-spektroskopische Untersuchungen an substituierten 1, 1-Dioxo-1, 2-thiazinen; Additivität der Substituenteneffekte

¹H- and ¹³C-N.M.R. Spectroscopic Investigations of Substituted 1, 1-Dioxo-1, 2-thiazines; Additivity of the Substituent Effects . The influence of various XCH₂ substituents (X: Cl, Br, I, SCN, SO₂CH₃, SC(NH₂)₂^⊕, Py^⊕) in the 3-, 5- and 3, 5-position of the 1, 1-dioxo-2-phenyl-1, 2-thiazine on the ¹H- and ¹³C-n.m.r. chemical shifts of the ring atoms is described. The substituent effects are additive. The ¹H- and ¹³C-n.m.r. chemical shifts of the 3, 5-substituted 1, 1-dioxo-1, 2-thiazines can be calculated from increments derived from the 3- and 5-substitued compounds.     

Study of third‐order optical nonlinearities of substituted hydrazones in PMMA

We investigated the third‐order nonlinear optical properties of donor–acceptor substituted hydrazones doped into PMMA matrix using single beam Z‐scan technique at 532 nm. The magnitude of third‐order susceptibility, χ⁽³⁾ is of the order of 10⁻¹³esu. The nonlinear refractive index, n₂ and the molecular second order hyperpolarisability, γ_h are of the order of 10⁻¹¹esu and 10⁻³²esu, respectively. The compounds exhibit larger third‐order NLO properties in PMMA host when compared to the pure compounds. The study reveals that these hydrazones are a good candidate of nonlinear optical materials for photonic applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Heterocyclisch substituierte Arendiazoniumsalze mit erweiterter spektraler Empfindlichkeit. II. 4-(1-Heterocycliden-2,3-diaza-prop-2-en-3-yl)-benzendia-zoniumtetrafluoroborate

Heterocyclic Substituted Arenediazonium Salts with a Long-wave-length Range of Sensitivity. II. 4-(1-Heterocycliden-2,3-diaza-prop-2-en-3-yl)-arenediazonium tetrafluoroborates The title compounds ( 3 ) are obtained by reaction of aromatic bis-diazonium salts with substituted 2-benzylidene-1,3-dithioles and 2-benzylidene-1,3-diselenole, respectively. The maximum of the long wave-length absorption band of 3 varies from 580 nm up to 665 nm depending on the structure of the compound. The quantum yields of the photolysis of the diazonium salts 3 are low (1 · 10⁻⁴ to 7 · 10⁻³). The azo dyes obtained from 3 with usual azo-couplers absorb in a shorter wave-length range than the corresponding diazonium salts themselves (hypso-coupling effect).     

Photochemie und Photophysik von 3-(2-Isoxazolinyl)-phenylketonen

Photochemistry and Photophysics of 3-(2-Isoxazolinyl)-phenylketones 3-Benzoyl-Δ²-1,2-oxazolines ( 1–6 ) are formed by 1,3-dipolar cycloaddition between benzoylnitril-N-oxide ( 8 ) and dihydrofurane 9 or 1,3-dioxep-5-enes ( 10a–c ). The preparative yields are small due to the competitive dimerization of the dipole 8 . Two stereoisomers are obtained by using 2-substituted 1,3-dioxep-5-enes as dipolarophiles. The different steric position of the substituents in 3–6 gives rise to different spectral data. The synthesized ketones possess triplet states with a high degree of charge transfer character. Therefore, the ability to H-abstraction reaction from alcohols is small. For ketone 2 and methanol as H-donor a rate constant of k = 4,1 · 10² M⁻¹s⁻¹ is determined. Also by electron transfer reactions with triethylamine and some onium compounds the reactivity of the T₁ of the ketones 1–6 is less compared to those of nπ* excited ketones. The photolysis of the ketones takes place very unselectively and leads to a product mixture. The quantum yields for the decay of the ketones are 10⁻² to 10⁻³.     

Preparation and properties of 2-Dialkylamino-5-haloacetyl-thiazoles and 4-(2-Dialkylamino-5-thiazolyl)-thiazoles

By the reaction of N-acylthioureas 7 with 1,3-dichloroacetone 9 2-dialkylamino-5-chloroacetyl-thiazoles 11 are available. These compounds react with thioureas or arylthioamides under heterocyclisation to give bis-(2-dialkylamino-5-thiazolyl)-ketones 13 , 2-aryl-4-(2-dialkylamino-5-thiazolyl)-thiazoles 14 , or 2-dialkylamino-4-(2-dialkylamino-5-thiazolyl)-thiazoles 15 , resp., from which the last-mentioned compound exhibit a high reactivity towards several electrophilic reagents. Thus, deeply colored cyanovinyl, arylazo, and arylmethine substituted bisthiazole dyes 17, 18 , and 19 , resp., have been formed.     

Pyryliumverbindungen. XXII. 1H-NMR- und UV-spektroskopische Untersuchungen zur Isomerisierung von Pseudobasen unsymmetrisch substituierter 2, 4, 6-Triarylpyryliumsalze

Pyrylium Compounds. XXII. ¹H-N.M.R. and U.V. Spectroscopic Investigations on the Isomerization of Pseudobases of Unsymmetrically Substituted 2, 4, 6-Triarylpyrylium Salts The kinetics and mechanism of the isomerization of the title compounds, the pentene 1,5-diones 2 and 3 , were studied by ¹H-n.m.r. and u.v. spectroscopy. The equilibrium constants measured vary little near 1, indicating the small influence of substituents on the equilibrium position. The mutual rearrangement 2 ⇄ 3 proved to be a base-catalized reaction which is characterized by strictly linear Hammett correlation between 1g k and Σσ_p. The results obtained suggest resonance-stabilized anions of type 4 as intermediates. - Pseudobases of 3-alkyl-2, 4, 6-triarylsubstituted pyrylium salts do not undergo a reversible isomerization.     

A novel synthesis of 1,3 Thiazetidine-2-one and 1,3-Oxazine-2-one Derivatives

In the reactions of acetylthioacetanilides ( 1a–c ) and diacetylthioacetanilides ( 3a–f ) with phosgene 1,3-thiazetidine-2-one ( 2a–c ) and 1,3-oxazine-2-one ( 5a–f ) were obtained respectively. The structures of new compounds were elucidated by elemental analyses, i.r., ¹H-n.m.r., m.s., for 1d–f by ¹⁹F-n.m.r. and for 2a and 5a by ¹³C-n.m.r. spectral data.     

1,2,3-Triazabutadiene. XIII. UV-vis-spektroskopische Untersuchungen zur Protonierung Z-E-isomerer 1-Aryl-3-[3-methylbenzthiazolinyliden-(2)]- und 1-Aryl-3-[1,3-dimethylbenzimidazolinyliden-(2)]-triazene

1,2,3-Triazabutadienes. XIII. U.V.-vis-Spectroscopic Investigations of the Protonation of Z-E-Isomeric 1-Aryl-3-[3-methylbenzthiazolinyliden-(2)]- and 1-Aryl-3-[1,3-dimethylbenzimidazolinyliden-(2)]-triazenes The u.v.-vis absorption spectra of Z-E-isomeric 1-aryl-3-[3-methylbenzthiazolinyliden-(2)]- and 1-aryl-3-[1,3-dimethyl-benzimidazolinyliden-(2)]-triazenes 1–3 resp. 4 show a pronounced halochromic effect in the presence of acids. The reason is the protonation of the N¹-atom of the triazabutadiene chain whereby the energetically favourable structure of a diazatrimethine is formed. The magnitude of the halochromic effect depends on the substituents in the aryl and benzo residue and on the Z-E-structure of the compounds.     

Aza-Enamine. IX. UV/VIS- und NMR-spektroskopische Interpretation der Elektronenstruktur in Aldehydhydrazonen und daraus hergestellten Aza-Trimethinen

Aza-Enamines. IX. UV/VIS and N.M.R. Spectroscopic Interpretation of the Electron Structure in Aldehyde-N,N-dialkylhydrazones and in Aza-trimethines Prepared from These The n.m.r. and u.v./vis spectroscopic data of the compounds 2 , 3 and 4 – synthesized by electrophilic substitution at the azomethine carbon atom of the aldehyde hydrazones 1 according to the aza-enamine-concept – are reported. Compared to the respective C-atom of the starting hydrazones 1 the azomethine-C-atom of the compounds 2 – 4 exhibits a ¹³C-n.m.r. shift not corresponding to usual substituent effects. Our interpretation for this and for the u.v./vis spectroscopic data, too, is a simultaneous existence of both an aza-trimethine structural unit and an aromatic structure in the compounds 2 – 4 .     

Synthese und Reaktionen von 2-[Bis-(alkylthio)-methyliden]-indan-1,3-dionen

Synthesis and Reactions of 2-[Bis-(alkylthio)-methyliden]-indan-1,3-diones The 2-[bis-(alkylthio)-methyliden]-indan-1,3-diones 3 and especially the methyl-compound 3a react with nucleophiles by substitution of the CH₃ S group. The reaction with amines are yields the S,N or N,N-acetales 7 and 8 , respectively. Diamines, amino hydroxy- or amino-mercapto compounds as dinucleophiles give the cyclic compounds 9 or the condensed heterocycles 12 and 16 , where the carbonyl group has been integrated in the cyclisation. Also carbanions react with 3a under substitution. The structures of the final products are determined with ir-, ¹H-n.m.r.- and ms-spectra.     

The synthesis, crystal structures and photophysical properties of a series of novel 4,6-diphenyl-1,9-anthrazolines

The synthesis and properties of a series of nine new 4,6-diphenyl-1,9-anthrazolines molecules 1a-1i are reported. Compounds 1a-1i were synthesized by Friedländer condensation of 4,6-dibenzoyl-1,3-phenylenediamines and acetyl-functionalized compounds in the presence of polyphosphoric acid as catalyst, in yields ranging from 60% to 94%. The 4,6-diphenyl-1,9-anthrazolines are thermally robust with high decomposition temperatures (>371.0 °C) and high melt transitions (215.1-322.8 °C). Compounds 1a and 1f crystallized in the triclinic system with the space groups P-1. All of them show the lowest energy absorption bands (λ_max^Abs: 397-454 nm), revealing low optical band gaps (2.55-3.00 eV). The compounds emit blue fluorescence with λ_max^Em ranging from 432 to 493 nm in dilute toluene solution. 4,6-Diphenyl-1,9-anthrazolines 1a-1i have a formal reduction potential in the range −1.02 to −1.19 V (versus SCE) and estimated electron affinities (LUMO levels) of 3.21-3.38 eV. These results demonstrate that the new 4,6-diphenyl-1,9-anthrazolines are promising thermally stable n-type semiconductors for organic electronics.     

Substituenteneinfluß auf die T1- Energie und auf S1-T1-Energiegap bei ω-Phosphor-substituierten trans-Styrenen

Influence of Substituents on the T₁ Energy and the S₁-T₁ Energy Gap in ω-Phosphorus Substituted trans-Styrenes The fluorescence and the phosphorescence of 4-substituted ω-diphenylphosphinyl trans-styrenes 1 and analogous diphenylthiophosphinyl trans-styrenes 2 at 77 K indicate together with some oxygen-induced singlet-triplet absorption spectra a bathochromic shift of the lowest singlet (S₁) and the lowest triplet level (T₁) relatively to the S₁ and T₁ level of the unsubstituted compounds 1a and 2a , respectively. Donor substituents X in 4-position give rise to a shift of S₁, which is in the most cases much greater than that of T₁, so that the S₁–T₁ energy gap decreases. P(Y)R¹R² groups (Y = O, S) in ω-position of 1 and 2 effect a small bathochromic shift of the T₁ energy level only (130–900 cm⁻¹ relatively to unsubstituted styrene). S₁ is shifted 860–2080 cm⁻¹ to lower energies, however.     

Synthese von 2-alkoxysubstituierten Oligo- und Poly(1,4-phenylenethenylen)en und 2-Arylbenzo[b]furanen mit Hilfe der Siegrist-Reaktion

Synthesis of 2-Alkoxy Substituted Oligo- and Poly(1,4-phenyleneethylene)s and 2-Arylbenzo[b]furanes by Applying the Siegrist Reaction Alkylation of 2-hydroxy-4-methylbenzaldehyde ( 1 ) yields the 2-alkoxy-4-methylbenzaldehydes ( 2a-l ) which can be easily transformed to the Schiff bases 3a-l . The intermolecular self-condensation in a strongly alkaline medium leads to the oligo- and poly(1,4-phenyleneethenylene)s ( 4a-i ) with an outstanding regular constitution and overall (E)-configuration. The terminal N-arylamino group can be cleaved by hydrolysis generating the compounds 5a-i . An intramolecular condensation forming the benzo[b]furanes 6j,k is observed for 3j,k – due to the activated OCH₂ group in 2-position. Finally, both the 4-CH₃ as well as the 2-OCH₂ group take part in the reaction of 3l . The twofold Schiff base 3m , obtained from 1 via 2m , yields the ladder polymer 7m .