Beiträge zum Reaktionsverhalten von Derivaten der Imidodithiokohlensäure. II [1]. 7-Hydroxythiazolo[4,5-b]pyridone-(5)

Contributions to the Reaction Behaviour of Derivatives of Imidodithiocarbonic Acid. II. 7-Hydroxythiazolo[4,5-b]pyrid-5-ones Derivatives of cyanimidocarbonic acid 1 react with ethyl γ-bromoacetoacetate to ethyl thiazolylacetates 2 which are converted into 7-hydroxythiazolo[4,5-b]pyrid-5-ones 3 by acid or base catalyzed cyclisation. These compounds can be alkylated as well as acylated. The 7-hydroxy group is exchangeable for chlorine. Furthermore in position 6 electrophilic sulfonation can take place.     

Synthesis of Thiazolo(4,5-b)-quinoxalines and related compounds

The reaction of 2,3,7-trichloroquinoxaline ( 1 ) or 2,3-dichloro-7-bromoquinoxaline ( 2 ) with thiourea in DMSO gave 6,6′-dichloro- or 6,6′-dibromodiquinoxalino[2,3-b:2′:3′-e]1,4-dithiien ( 3 or 4 ). However, 1 or 2 reacts with thiourea in ethanol to give ( 3 or 4 ) beside 7-chloro- or 7-bromo-2-imino-2,3-dihydrothiazolo[4,5-b] quinoxaline ( 5 or 6 ) respectively. Interaction of 1 or 2 with acetone thiosemicarbazone gave 7-chloro- or 7-bromo-3-amino-2-imino-2,3-dihydro-thiazolo[4,5-b] quinoxaline hydrochloride ( 13 or 14 ) respectively. Cyclization of 7-chloro- or 7-bromo-3-amino-2-imino-2,3-dihydrothiazolo[4,5-b]quinoxaline ( 15 or 16 ) on treatment with aromatic acid chlorides or isothiocyanates succeeded to give 19—21 or 28 and 29 .     

The synthesis of fused and pendant pyrazole heterocyclic compounds from 5-amino-3-methyl-1-phenylpyrazole and their evaluation as fluorescent brightening agents

5-Amino-3-methyl-1-phenylpyrazole ( 1 ) has been condensed with EMME ( 2 a) and EMCA ( 2 b) and the resulting ethyl 5-aminoacrylates ( 3 a–b) cyclized to pyrazolo[3,4,-b]pyridines ( 4 a–b). 3-Methyl-1-phenylpyrazol-5-yl diazonium salt ( 7 ), prepared from ( 1 ) was coupled with tobias acid ( 8 ) and 2-methoxy-6-aminoquinoxaline ( 9 ) to get the corresponding O-aminoarylazo and heterylazo dyes ( 10 ) which were oxidatively cyclized to 2-N-(3-methyl-1-N-phenylpyrazol-5-yl)-1,2,3-triazolo[4,5-a] naphthalene and [4,5-f] quinoxaline derivative ( 11 ). The spectral properties of the compounds ( 4 a–b, 5 , 6 , 11 a–b) were studied.     

Eindeutige Synthese des 4,7-Dihydro-4-oxo-1 H-pyrazolo[3,4-b]pyridins – Bemerkungen zur „(N?C)-Umlagerung”︁ von (2-Alkoxycarbonyl-vinyl-amino)pyrazolen

Unambiguous Synthesis of 4,7-Dihydro-4-oxo-1H-pyrazolo[3,4-b]pyridine — Further Comments on the “(N C)-Rearrangement” of (2-Alkoxycarbonyl-vinyl-amino)pyrazols 4,7-Dihydro-4-oxo-1H-pyrazolo[3,4-b]pyridine 1a is synthesized by decarboxylation of 1-benzyl-5-carboxy-4-hydroxy-pyrazolo[3,4-b]pyridine 4b and debenzylation of 1-benzyl-4,7-dihydro-4-oxo-pyrazolo[3,4-b]pyridine 1b with sodium in liquid ammonia. The product from 3-amino-pyrazol and methyl propiolate, formerly described as 1a , obviously is the 6-oxo isomer 2a . Use of the parameter δ¹³(CO) for the structural assignment of pyrazolo[3,4-b]pyridones is only permitted, if in the corresponding media mainly the oxo-tautomer is existing. It is again demonstrated that DMSO is often an insufficient medium. Debenzylation of 1b and similar compounds with SeO₂ is only possible, if the α-position of CO is blocked by a substituent. Otherwise diselenids of type 6 are formed. This obviously is a general reaction of cyclic lactames. The cyclisation of (2-alkoxycarbonyl-vinyl-amino)pyrazols 7 in acidic media, and with catalytical amounts of the corresponding amino-pyrazols gives 6,7-dihydro-6-oxo-pyrazolo[3,4-b]pyridines 2 via amino 4-(2-alkoxycarbonyl-vinyl)pyrazols 8 , i.e. via products of an “(N C)-rearrangement”, while by thermal cyclisation of 7 4,7-dihydro-4-oxo-pyrazolo[3,4-b]pyridines 1 are formed.     

Comprehensive and Facile Synthesis of Some Functionalized Bis-Heterocyclic Compounds Containing a Thieno[2,3-b]thiophene Motif

A comprehensive and facile method for the synthesis of new functionalized bis-heterocyclic compounds containing a thieno[2,3-b]thiophene motif is described. The hitherto unknown bis-pyrazolothieno[2,3-b]thiophene derivatives 2a-c, bis-pyridazin othieno[2,3-b]thiophene derivatives 4, bis-pyridinothieno[2,3-b]thiophene derivatives 6a,b, and to an analogous bis-pyridinothieno[2,3-b]thiophene nitrile derivatives 7 are obtained. Additionally, the novel bis-pyradazinonothieno[2,3-b]thiophene derivatives 9, and nicotinic acid derivatives 10, 11 are obtained via bis-dienamide 8. The structures of all newly synthesized compounds have been elucidated by (1)H, (13)C NMR, GCMS, and IR spectrometry. These compounds represent a new class of sulfur and Nitrogen containing heterocycles that should also be of interest as new materials.     

2-Arylamino-thiophen-3-carbonsäurederivate

2-Arylamino-thiophene-3-carboxylic Acid Derivatives The title compounds 3 are synthesized by reaction of 2-amino-thiophene-3-carboxylic acid derivatives 1 with anilines. The nucleophilic 5-position in 3 allowed the synthesis of 5-aryliden-Δ³-thiolen-2-one-imines 5 , 6 and the oxidative coupling to yield the azo compound 7 . 1-Aryl-thieno-[2,3-d]pyrimid-4-ones 9 , the thieno[2,3-b]chinolin-4-one 10 and the 4-chloro thieno[2,3-b]chinolines 10 , 11 can be obtained from 3 .     

Quinoxaline derivatives as long wavelength photosensitizers in photoinitiated cationic polymerization of diaryliodonium salts

The present paper is focused on visible light initiated cationic polymerizations. Photoinitiated polymerization of representative vinyl ether and oxirane monomers using two quinoxaline derivatives; namely (2-(2,3-dihydrobenzo [b][1,4]dioxin-6-yl)-3-(2,3-dihydrobenzo[b]-[1,4]dioxin-7-yl)-5-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-8-(2,3-dihydrothieno[3,4-b][1,4]dioxin-7yl) quinoxaline) (DBQEd) and 2,3,5,8-tetra(thiophen-2-yl)quinoxaline (TTQ) are studied. Novel dyes based on the quinoxaline skeleton are employed as efficient photosensitizers in cationic photopolymerizations. Polymerizations were initiated at room temperature upon irradiation with long-wavelength UV and visible lights in the presence of diphenyliodonium hexafluorophosphate (Ph₂I⁺PF₆^?). The progress of the polymerizations was monitored by optical pyrometry (OP). Solar irradiation is also employed to carry out the cationic polymerization of a diepoxide monomer in the presence of air.     

吡啶并吡嗪/咪唑杂环化合物的合成研究

以2,3-二氨基吡啶或2,3,5,6-四氨基吡啶盐酸盐等为原料合成了吡啶并吡嗪、吡啶并咪唑及吡啶并二咪唑氮杂环衍生物。探讨了反应条件对产物收率的影响,初步确定了优化反应条件。对2,3-二甲基吡啶并吡嗪及2,3-二乙基吡啶并吡嗪的合成,氯化铵-甲醇体系具有明显的催化效果。使用4,5-二羟基咪唑烷-2-酮代替乙二醛与2,3-二氨基吡啶反应,可显著提高吡啶并吡嗪的合成收率;对于吡啶并咪唑和2-甲基吡啶并咪唑的合成,以2,3-二氨基吡啶与原甲酸三乙酯或原乙酸三甲酯为原料,在磷钼酸催化下反应,收率达50%以上;对于吡啶并[2,3-b:5,6-b']二咪唑和2,6-二甲基吡啶并[2,3-b:5,6-b']二咪唑的合成,分别以2,3,5,6-四氨基吡啶盐酸盐与原甲酸三乙酯和原乙酸三甲酯为原料在磷钼酸催化下反应,收率可达68.7%和66.5%。     

咪唑并吩嗪基苯硼酸衍生物的合成与荧光特性研究

合成了2种含有1 H-咪唑[4,5-b]并吩嗪荧光团的苯硼酸探针分子。它们均有大的斯托克斯位移(分别为136nm和141nm)和荧光发射波长(>540nm)。其中化合物3b:(2-(1H-咪唑[4,5-b]并吩嗪-2-基)苯硼酸)的荧光强度小于3a:(4-(1H-咪唑[4,5-b]并吩嗪-2-基)苯硼酸),这是由于分子内的B-N间的相互作用影响了分子内电荷发生转移。研究表明设计合成的咪唑并吩嗪基苯硼酸类荧光糖探针可选择性识别不同结构的糖。     

Oxidative Kupplung von 5-Amino-pyrazolen mit p-Phenylendiaminen

Oxidative Coupling of 5-Aminopyrazoles with p-Phenylenediamines By oxidative coupling of 5-amino-3-methyl-1-phenyl-pyrazole 4 with N,N-diethyl-p-phenylenediamine the 4-(4-N,N-diethylamino-phenylimino)-3-methyl-1-phenyl-2-pyrazolin-5-imin 5 is formed. 5 is oxidized very easily to the 1H-pyrazolo[3,4-b]quinoxaline 6a . The Z/E-isomerism of the azomethine dye is investigated by dynamic n.m.r.-spectroscopy. 1H-Pyrazolo[3,4-b]quinoxalines (6a–d) are also formed by reaction of 1,3-disubstituted 5-aminopyrazoles with p-nitroso-dialkylanilines.     

A Novel and Expedient Approach to New Thiazoles, Thiazolo[3,2-a]pyridines, Dihydrothiophenes, and Hydrazones Incorporating Thieno[2,3-b]thiophene Moiety

This paper reports details about the synthesis of a series of novel functionalized symmetrical bis-heterocyclic compounds containing a thieno[2,3-b]thiophene motif. Bis-thiazole derivatives 2, 3a-c and thiazolo[3,2-a]pyridine derivatives 4a-c are achieved. The hitherto unknown dihydrothiophene derivatives 6a-dvia bis-pyridimium salt 5 are obtained. Additionally, the novel hydrazonothieno[2,3-b]thiophene derivatives 10a-c are obtained via bis-tosylacetylthieno[2,3-b]thiophene derivative 9. All compounds are characterized by (1)H-, (13)C-NMR, GCMS, IR, and UV-vis spectrometry. These compounds represent a new class of sulfur and nitrogen containing heterocycles that should also be of interest as new materials.     

Heterocyclen aus o-Aminoketonen. XXIII [1]. Umsetzung von o-Aminoketonen mit Dicarbonsäuren

Heterocyclic Compounds from 2-Aminoketones. XXIII. Reaction of o-Aminoketones with Dicarboxylic Acids Saturated aliphatic dicarboxylic acids (C₄ C₇ and C₁₀) react with 2-aminobenzophenones in polyphosphoric acid (PPA) to form substituted derivatives of partial hydrogenated benzo[b][1,8]naphthyridines 2a–d and 2-anilino-quinoline-3-alkanoic-acids 5a–h . The heterologous derivatives of glutaric acid — containing S or N instead of β-CH₂ — with aminoketon undergo ring closure to give thiazino- and oxazino[3,2-b]quinolines 2e–h . Aromatic o-dicarboxylic acids with a –CH₂ CO- group react with aminoketones to yield anilinosubstituted 5i or pyrano[b]-condensed quinolines 6 . N,N′-Di-(2-benzoylphenyl)-dicarboxylicacid-diamides 3 with ammonia undergo cyclisation to α,ω-di-(4′phenyl-quinazolinyl-(2′))-alkanes 4 .     

A copolymer based on benzo[1,2-b:4,5-b′]dithiophene and quinoxaline derivative for photovoltaic application

A D–A–D copolymer (PBDTQx) with a bandgap of 1.78 eV, containing alkoxy-substituted benzo[1,2-b:4,5-b′]dithiophene (BDT) as donor and quinoxaline derivative (Qx) as acceptor, was synthesized by Stille coupling reaction. In order to study the photovoltaic property of PBDTQx, polymer solar cells (PSCs) were fabricated with PBDTQx as the electron donor blended with [6,6]-phenyl-C61-butyric acid methyl ester (PC₆₁BM) as the electron acceptor. The power conversion efficiency (PCE) of PSC was 1.01% for an optimized PBDTQx: PC₆₁BM ratio of 1:5, under the illumination of AM 1.5, 100 mW/cm². The results indicated that PBDTQx was a promising donor candidate in the application of polymer solar cells.     

Synthese und 13C-NMR-Spektroskopie einiger Pyrrolo[2,1-b]chinazoline

Synthesis and ¹³C-N.M.R.-Spectroscopy of Pyrrolo-[2,1,-b]quinazoline In 6- or 7-position substituted pyrrolo-[2,1-b]quinazoline derivatives were synthesized by reacting substituted anthranilic acid derivatives with either 4-amino-butyric acid or 2-methoxy-Δ¹-pyrroline. Furthermore some at C-3 substituted desoxyvasicinone derivatives were prepared. Using these compounds and different n.m.r. spectroscopie techniques the ¹³C resonance signals of all carbon atoms in peganine were assigned.     

New Bioactive Fused Triazolothiadiazoles as Bcl-2-Targeted Anticancer Agents

A series of 3-(6-substituted phenyl-[1,2,4]-triazolo[3,4-b]-[1,3,4]-thiadiazol-3-yl)-1H-indoles (5a–l) were designed, synthesized and evaluated for anti-apoptotic Bcl-2-inhibitory activity. Synthesis of the target compounds was readily accomplished through a reaction of acyl hydrazide (1) with carbon disulfide in the presence of alcoholic potassium hydroxide to afford the corresponding intermediate potassium thiocarbamate salt (2), which underwent cyclization reaction in the presence of excess hydrazine hydrate to the corresponding triazole thiol (3). Further cyclisation reaction with substituted benzoyl chloride derivatives in the presence of phosphorous oxychloride afforded the final 6-phenyl-indol-3-yl [1,2,4]-triazolo[3,4-b]-[1,3,4]-thiadiazole compounds (5a–l). The novel series showed selective sub-micromolar IC₅₀ growth-inhibitory activity against Bcl-2-expressing human cancer cell lines. The most potent 6-(2,4-dimethoxyphenyl) substituted analogue (5k) showed selective IC₅₀ values of 0.31–0.7 µM against Bcl-2-expressing cell lines without inhibiting the Bcl-2-negative cell line (Jurkat). ELISA binding affinity assay (interruption of Bcl-2-Bim interaction) showed potent binding affinity for (5k) with an IC₅₀ value of 0.32 µM. Moreover, it fulfils drug likeness criteria as a promising drug candidate.     

Synthesis of new Thiopyranopyridines

The synthesis of 5H-thiopyrano[4,3-b]pyridines, 8H-thiopyrano[3,4-b]pyridines, 1H-thiopyrano[3,4-c]pyridines and 1H-thiopyrano[4,3-c]pyridines from methyl pyridine esters 5–8 and nitriles 17–20 by simple photobromination, followed by reaction of the intermediate bromomethyl derivative with methyl thioglycolate and subsequent base induced cyclisation of the latter are reported.     

6-甲基-2-苯基咪唑[2,1-b]并-1,3,4-噻二唑-5-N'-取代苯基亚甲基碳酰肼的设计与合成

根据已有的具有抗肿瘤活性的咪唑[2,1-b]并-1,3,4-噻二唑类化合物的结构及其构效关系,以2-氨基-5-苯基-1,3,4-噻二唑和溴代乙酰乙酸乙酯为原料设计并合成了8个6-甲基-2-苯基咪唑[2,1-b]并-1,3,4-噻二唑-5-碳酰肼的腙类衍生物.通过1HNMR、LC-MS、IR等方法对其结构进行了确证.     

2-巯基-5-甲氧基咪唑并[4,5-b]吡啶的合成及表征

以2,6-二氯吡啶为原料,用甲醇/氢氧化钠体系进行甲氧基取代,用硝酸钾/浓硫酸进行硝化反应,再用氨水氨解,制得2-氨基-3-硝基-6-甲氧基吡啶(Ⅲ),最后用氯化亚锡于75℃反应4h还原Ⅲ,再用二硫化碳环化合成2-巯基-5-甲氧基咪唑并[4,5-b]吡啶,总收率为43.6%。产物结构用IR、1HNMR和MS作了表征。     

Synthese von Pyrrolo[1,2-a]chinazolinonen,Indolo[1,2-a]chinazolinonen,Pyrrolo[1,2-a]thieno[3,2-e]pyrimidinonen,Benzothieno[3,2-e]-pyrrolo[1,2-a]pyrimidinonen und 6H-Cyclohepta[4,5]thieno-[3,2-e]pyrrolo[1,2-a]pyrimidinonen

A Synthesis of Pyrrolo[1,2-a]quinazolinones, Indolo[1,2-a]-quinazolinones, Pyrrolo[1,2-a]thieno[3,2-e]pyrimidinones, Benzothieno[3,2-e]pyrrolo[1,2-a]pyrimidinones and 6H-Cyclohepta[4,5]-thieno[3,2-e]pyrrolo[1,2-a]pyrimidinones α-Cyano-γ-halo-crotonnitriles ( 1 ) synthesized (e.g. via Knoevenagel reaction and by subsequent halogenation) react with primary arylamines ( 2 ) to substituted 1-aryl-2-amino-3-cyano-pyrroles ( 3 ). We found that the reaction yields pyrrolo[1,2-a]quinazolin-5-ones ( 6 ) in a one-pot procedure if anthranilic esters ( 4 ) and compounds of the general formula 5 are used. The analogous treatment with 2-amino-3-ethoxy-carbonyl-thiophene derivatives ( 8 ) leads to pyrrolo[1,2-a]thieno-[3,2-e]pyrimidin-5-ones, benzothieno[3,2-e]pyrrolo[1,2-a]pyrimidinones and 6H-Cyclohepta[4,5]-thieno[3,2-e]pyrrolo[1,2-a]pyrimidinones as thiadiazastereoid analogs 9 . This reaction is suitable for the synthesis of various heterocyclic ring systems.     

New potential antitumoral fluorescent tetracyclic thieno[3,2-b]pyridine derivatives: interaction with DNA and nanosized liposomes

Fluorescence properties of two new potential antitumoral tetracyclic thieno[3,2-b]pyridine derivatives were studied in solution and in liposomes of DPPC (dipalmitoyl phosphatidylcholine), egg lecithin (phosphatidylcholine from egg yolk; Egg-PC) and DODAB (dioctadecyldimethylammonium bromide). Compound 1, pyrido[2',3':3,2]thieno[4,5-d]pyrido[1,2-a]pyrimidin-6-one, exhibits reasonably high fluorescence quantum yields in all solvents studied (0.20 ≤ ΦF ≤ 0.30), while for compound 2, 3-[(p-methoxyphenyl)ethynyl]pyrido[2',3':3,2]thieno[4,5-d]pyrido[1,2-a]pyrimidin-6-one, the values are much lower (0.01 ≤ ΦF ≤ 0.05). The interaction of these compounds with salmon sperm DNA was studied using spectroscopic methods, allowing the determination of intrinsic binding constants, Ki = (8.7 ± 0.9) × 103 M-1 for compound 1 and Ki = (5.9 ± 0.6) × 103 M-1 for 2, and binding site sizes of n = 11 ± 3 and n = 7 ± 2 base pairs, respectively. Compound 2 is the most intercalative compound in salmon sperm DNA (35%), while for compound 1 only 11% of the molecules are intercalated. Studies of incorporation of both compounds in liposomes of DPPC, Egg-PC and DODAB revealed that compound 2 is mainly located in the hydrophobic region of the lipid bilayer, while compound 1 prefers a hydrated and fluid environment.