Syntheses of deep coloured aminonaphthoquinonoid dyes. Reaction of dichloronaphthazarins with 2-aminobenzenethiol and related compounds

The reaction of 2,3-dichloronaphthazarin 1a with potassium 2-amino-benzenethiolate gives the ring-closure product 10,11-dithia-5H,16H-5, 16-diazadinaphtho[2,3a],[2,3c]-1,4-naphthoquinone 9 in 86.2% yield together with small amounts of 5-hydroxy-6-chloro-7-thia-12H-12-azanaphtho[2,3a]-1,4-naphthoquinone 8. Dye 9 is green in colour and absorbs infrared light at 727 nm. Oxidation of 9 by hydrogen peroxide gives 10,11-dithia-5H,16H-5,16-diazadinaphtho[2,3a],[2,3c]-1,4-naphtho-quinone-10,11-dioxide 14 which absorbs infrared light at 827nm. The reaction of 1a with 2-aminoethanethiol gives 5-hydroxy-6-chloro-7-thia-10-aza-8, 9,10-trihydrobenzo[2,3a]-1,4-naphthoquinone 4 and 2,3-di-chloro-5-hydroxy-7-thia-10-aza-8, 9,10-trihydrobenzo[2,3a]-1,4-naphtho-quinone 5 in yields of 14.2 % and 3.2 %, respectively.     

氯虫酰胺的合成与杀虫活性

以2,3-二氯吡啶和2-甲基-4-氯苯胺为起始原料,经过多步反应得到6-氯-2-(3-溴-1-(3-氯吡啶-2-基)-1H-吡唑-5-基)-8-甲基-4H-3,1-苯并嗪-4-酮,再与甲胺反应得到目标产物氯虫酰胺,经核磁验证其结构,生物活性测定结果表明该化合物对鳞翅目害虫如小菜蛾、甜菜夜蛾、稻纵卷叶螟等具有优异的杀虫活性。     

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.     

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 .     

Ring closure reaction of 5-hydroxy-pyrido[2,3-d]pyrimidine-2,4,7-triones to benzo[b]pyrimido[4,5-h]1,6-naphthyridine-1,3,6-triones

N-Substituted aminouracils ( 1 ) react with malonates by cyclocondensation to 5-hydroxy-pyrido[2,3-d]pyrimidine-2,4,7-triones ( 2 ), which give with triethylorthoformate and aniline 6-(phenylaminomethylene)-pyrido[2,3-d]pyrimidine-tetraone ( 3 ). Halogenation of 2a - d (with R² = Me) with phosphorylchloride leads to 5,7-dichloro-pyrido[2,3-d]pyrimidine-2,4-diones ( 4 ) by cleavage of the methyl group at N-8, whereas Vilsmeier reaction of 2 affords 5-chloro-6-formyl derivatives ( 6 ), which cyclize with arylamines to give benzo[b]pyrimido[4,5-h] 1,6-naphthyridines ( 9 ). Compounds 9 were obtained independently by amination of the tosylates 5 to the 5-arylamino compounds 8 , and Vilsmeier formylation to yield 9 .     

Phosphorescence of Large Polycyclic Aromatic Ketones

Phosphorescence measurements were performed for 6H-benzo[cd]-pyren-6-one (l), 2-nitro-benzo[hi]chrysen- 13-one (2), 2-bromo-di-benzo[a, de]anthracen- 13-one (3), and 7H-benzo[hi]chrysen-7-one (4) in an ethanol-ether-toluene mixed solution and the character of their lowest excited triplet (T₁) states were investigated. The phos horescence of the compounds appears at about 5,200 – 6,000 cm^?1 to the red of their fluorescence, indicating that the T, states have ππ^* character. On the other hand, the short phosphorescence lifetimes, 10 – 60 ms, suggest nπ^* transitions. Such a duality of the T₁ state seems to be characteristic of large polycyclic aromatic ketones. The polarized emission study revealed that the duality is ascribed to strong mixing of ππ^* and nπ^* natures.     

Zur Synthese von 6-nitrosubstituierten 2H-Benzo[b]thiopyran-Derivaten aus 2-Mercapto-5-nitro-benzaldehyd

About the Synthesis of 6-nitro-substituted 2H-Benzo[b]thiopyran Derivatives Starting from 2-Mercapto-5-nitro-benzaldehyde Benzene derivatives useful as C₃S-building blocks for the synthesis of 2H-benzo[b]thiopyrans are not easily available. The synthesis starting with 2-chloro-benzaldehyde via 2-chloro-5-nitrobenzalde-hyde to 2-mercapto-5-nitro-benzaldehyde-tert-butylimin 1b and its cyclisation to 2H-benzo[b]thiopyrans ( 2a – h ) and ( 3a – d ) is described. By reaction with acceptor substituted alkenes, e.g. acroleine or ω-nitrostyrene respectively 2-chloro-propenes, e.g. substituted ß-chloroacroleines or 2-chloro-propene-1,3-dicarboxylates the compounds 2a – h and 3a – d are obtained. Vilsmeier's reaction of the diester 3d with DMF/POCl₃ yields the formyl compound 4 .     

Reaction of pyridothiouracil with hydrazonoyl halides and the antimicrobial activity of the products,pyrido[2,3-d][1,2,4]triazolo-[4,3-a]pyrimidin-5(1H)-one derivatives

New functionalized pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidin-5(1H)-one derivatives were synthesized via reaction of the hydrazonoyl halides with 7-(4-nitrophenyl)-5-phenyl-2,3-dihydro-2-thioxopyrido[2,3-d]pyrimidin-4(1H)-one or its 2-methylthio derivative. The biological activity of the products has been evaluated. The mechanism and the regioselectivity of the studied reactions have been discussed.     

Palladium-Catalysed Amide-Directed Ligand Free C8-Olefination of 1-Naphthamides for the synthesis of 2,3-dihydro-1H-benzo[de]isoquinolin-1-ones

This work describes the palladium(II)-catalyzed regioselective C8-H olefination of 1-naphthamides. Interestingly, naphthamide fused lactam 2,3-dihydro-1H-benzo[de]isoquinolin-1-one derivatives were also synthesized in the case of a particular class of napthamides. This protocol was found well compatible with a diverse range of acrylates and styrenes leading to product formation in good yields along with a wide functional group tolerance. The developed strategy was further applied to the synthesis of different drug derivatives.     

Heterocyclic quinones. XVI. The Reaction of acid Amides with 2,3- Dichloro-1,4-naphthoquinone,a novel route to naphth[2,3-d]oxazole-4,9-diones

Heating acid amides 2 with 2,3-dichloro-1,4-naphthoquinone 1 in solvents like glycerol or ethylene glycol gave readily naphth [2,3-d] oxazole-4,9-diones 4 . The reaction was enhanced by addition of catalytic amounts of sodium hydrogencarbonate, but failed to proceed at all when attempted in low boiling polar or nonpolar solvents. 2-Amido-3-chloro-1,4-naphthoquinones 3 were produced as intermediates in these reactions.     

Die Nitril-Carboxamid-Umlagerung

The Nitrile Carboxamide Rearrangement By reaction of cyclohexanone-2-carboxamide ( 4 ) with cyan amide 1-cyano-cyclohex-1-en-2-yl-urea ( 6 ) is formed via nitrile carboxamide rearrangement. Whilst compound 6 with 1,2-diaminobenzene hydrochloride forms 11-amino-1 H-2,3,4,5-tetrahydrodibenzo[b,e][1,4]diazepin hydrochloride ( 8 and 8a ), compound 6 and 1,2-diaminobenzene form hexahydro-benzimidazo[1,2-c]-quinazolin-6-one ( 12 ). Compound 8 with sodium hydroxide yields 11-amino-1 H-2,3,4,11a-tetrahydrodibenzo[b,e]-[1,4]diazepin ( 9 ). Compound 6 reacts with cyclohexylamine to form N-(1-cyanocyclohex-1-en-2-yl)-N′-cyclohexyl urea ( 10 ). Compound 10 with 1,4- or 1,2-diaminobenzene hydrochloride yields compound 7 and 8 . In alkaline solution 10 cyclises to 4-amino-3-cyclohexyl-2,3,5,6,7,8-hexahydroquinazolin-2-one ( 11 ). Compound 4 and malonitrile form either 3-amino-4-cyano-1,2,5,6,7,8-hexahydro-isoquinol-1-one ( 13 ) or 1-amino-4-cyano-2,3,5,6,7,8-hexahydro-isoquinol-3-one ( 14 ). Compound 13 and alkaline formaldehyde react to cyanooctahydroisoquinoline-[2,3-c] [1,3,5]oxdiazin-6-one ( 17 ). 2-Cyanoethyl-cyclohexan-one-2-carboxamide ( 22 ), prepared by Michael-reaction from 4 and acrylonitrile, forms via nitrile carboxamide rearrangement 10-cyano-1,2,3,4,5,6,7,10-octahydroquinolin-2-one ( 24 ) and 2-(1′-cyano-cyclohexyl-2′-one)-propionic acid ( 25 ). Nucleophilic attack of the NH₂-group at the cyanogroup of compound 22 forms 5-(spirocyclohexan-2′-one)-hexahydropyridin-2,6-dione ( 27 ).     

Electrochemical polymerization of an electron deficient fluorene derivative bearing ethylenedioxythiophene side groups

A new low band gap polyfluorene derivative, poly(2,7-bis-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-5-yl)-fluoren-9-one) (PEFE), containing ethylenedioxythiophene as donor and fluorenone (FO) as an acceptor groups was electrochemically synthesized. Electrochemical polymerization of 2,7-bis-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-5-yl)-fluoren-9-one (EFE) was achieved in dichloromethane with 0.1 M tetrabutylammonium-hexafluorophosphate both via and potentiostatic methods. The polymer was characterized by cyclic voltammetry, UV-vis, FT-IR and NMR spectroscopic techniques. Spectroelectrochemical and electrochemical analysis revealed that the polymer film is both p- and n-dopable and can be successfully cycled and switched between its neutral and oxidized/reduced states. Furthermore, PEFE shows electrochromic behavior by a color change from brown to blue with a switching time of 1.65 s during oxidation with a high coloration efficiency (250 cm²/C). Fluorescence studies were also performed.     

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 .     

Synthesis of some new fused thiopyrano[2,3-d]thiazoles and their derivatives

A series of some new fused thiopyrano[2,3-d]thiazole derivatives have been synthesized by a stereo-selective hetero-Diels-Alder reaction of 5-(2,4-dihydroxy-benzylidene)-4-thioxo-thiazolidine derivatives 3a,b with acrylonitrile, ethyl acrylate, N-phenylmale-imide, ω-nitrostyrene and N-phenyl-1, 3, 4-triazole-2,5-dione. 5-Amino-9-hydroxy-dihydro-benzopyrano[3′,4′:4,5]thiopyrano[2,3-d]thiazol-6-one derivatives 14a,b have been synthesized by Michael addition of 3a,b with malononitrile. Structures and conceivable mechanisms are discussed.     

Synthesis and characterization of Cu(I) and Zn(II) complexes with new sulfur-bearing isoxazole- or pyrazole-based ligands

The synthesis of the new ligands 6-(5-methyl-1,2-oxazol-3-yl)-2,3-dihydro-5H-[1,4] dithiino[2,3-c]pyrrole-5,7(6H)-dione (isox′) and 6-(3-methyl-1H-pyrazol-5-yl)-2,3-dihydro-5H-[1,4]dithiino[2,3-c]pyrrole-5,7(6H)-dione (pyraz′) and their coordination chemistry toward Cu(I) and Zn(II), was studied. The ligands and their complexes were characterized using a combination of either multinuclear NMR (¹H and ¹³C{¹H}), HRMS, FTIR or Uv–Vis spectroscopy. The solid state structures of ligand isox′ and complexes [Cu(pyraz′)₂]OTf and [Zn(OOCCF₃)₂(pyraz′)₂] were determined. Interestingly, isox′ presents a yellow luminescence in its free form. Additionally, the ability of isox′ to coordinate as an N–O bidentate ligand or as an N–S bridge between two copper centers, forming a coordination polymer, is studied. The solid state structure of this Cu(I)-isox′ 1D coordination polymer is also reported.     

Synthesis of some new spiroheterocyclic pyrylium salts related to 1-oxa-4-thiaspiro[4.4] nonan-2-one and/or [4.5]decan-2-one as antimicrobial agents

1-Oxa-4-thiaspiro[4.4]nonan-2-one ( 1a ) and/or 1-oxa-4-thiaspiro[4.5] decan-2-one ( 1b ) were reacted with aniline and/or p-chloroaniline to afford the corresponding spirothiazolidinones ( 2a–d ). Reaction of 2a–d with chalcones gave 2-(α – paracylbenzyl)-4-aryl-1-thia-4-azaspiro[4.4]nonan-3-one and 2-(α-aracylbenzyl)-4-aryl-1-thia-4-azaspiro[4.5]decan-3-one ( 3a–p ) respectively. Compounds 3a–p were reacted with acetic anhydride and perchloric acid to yield the spiropyrano[2,3-d]thiazol[4]ium perchlorate derivatives 4a–p . The structures of the synthesized compounds were elucidated by elemental and spectroscopic ( IR and ¹H-NMR) analysis. All the prepared compounds were tested for their antimicrobial activities in comparison with tetracyclic as a reference compound.     

An efficient microwave-assisted synthesis of thieno[2,3- b ]quinolines under solvent-free conditions

A novel and efficient method for the synthesis of substituted thieno[2,3-b]quinolines has been developed. A simple one-pot reaction of 3-formyl-2-mercaptoquinolines 2a–l with 1-chloroacetone, 2-chloroacetamide, ethyl chloroacetate and 2-chloro-1-phenylethanone in presence of catalytic amount of potassium carbonate under microwave irradiation and solvent-free conditions gave thieno[2,3-b]quinolin-2-ylethanone derivatives 3a–e, thieno[2,3-b]quinoline-2-carboxamide derivatives 4a–e, ethyl thieno[2,3-b]quinoline-2-carboxylate 5a–e and phenyl(thieno[2,3-b]quinolin-2-yl)methanone derivatives 6a–e compounds respectively. The structures of all the newly synthesised compounds were elucidated on the basis of elemental analysis, IR, ¹H NMR and mass spectral data.     

A facile synthesis of some novel fused [1,2,4]triazolo[3,4-b][1,3,4]thiadiazol derivatives

A series of novel 3-[6-(4-substituted phenyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-3-ylmethyl]-5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidin-4(3H)-one derivatives (7a–7h) have been synthesized from 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile (1) through a multi-step reaction sequence. The key intermediate (6) on condensation with various substituted aromatic carboxylic acids in the presence of phosphorus oxychloride afforded the series of title compounds (7a–7h). The structures of all newly synthesized compounds were established on the basis of their IR, ¹H-NMR, ¹³C-NMR and liquid chromatography mass spectrometry spectral data.     

Tuning of the neutral state color of the π-conjugated donor-acceptor-donor type polymer from blue to green via changing the donor strength on the polymer

Two donor-acceptor-donor types of π-conjugated monomers were synthesized using Stille coupling reaction. Both monomers were found to produce electroactive polymers upon electrochemical oxidation. The effects of different donor substituents on the polymers' electrochemical and spectroelectrochemical properties were examined. Optical characterization revealed that the band gaps of poly(2-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(2,3-dihydrobenzo[b][1,4]dioxin-7-yl)-5,8-di(thiophen-2-yl)quinoxaline) (PDBQTh) and poly(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-7-yl)quinoxaline) (PDBQEd) were 1.5 eV and 1.3 eV, respectively. PDBQEd reveals two distinct absorption bands as expected for this type of donor-acceptor-donor polymer at 423 and 738 nm, while PDBQTh has a single absorption band at 630 nm. The colorimetry analysis revealed that while PDBQTh has a blue color, PDBQEd showed a green color in the neutral state. PDBQEd revealed reversible n-doping.     

Epoxidation of E-1,4-poly(2-triethylsilyl-1,3-butadiene) and E-1,4-poly-[2,3-bis(trimethylsilyl)-1,3-butadiene] Stereochemical analysis of E-1,4-poly(2,3-epoxy-2-triethylsilyl-1,3-butadiene) and E-1,4-poly-[2,3-bis(trimethylsilyl)-1,3-butadiene] by 13C and 29Si NMR

Summary Reaction of E-1,4-poly(2-triethylsilyl-1,3-butadiene) (I) with m-chloroperbenzoic acid (MCPBA) yields E-1,4-poly(2,3-epoxy-2-triethylsilyl-1,3-butadiene) (II). Similar reaction of E-1,4-poly[2,3-bis(trimethylsilyl)-1,3-butadiene] (III) with MCPBA gives E-1,4-poly[2,3-epoxy-2,3-bis(trimethylsilyl)-1,3-butadiene] (IV). The product polymers have been characterized by ¹H, ¹³C, and ²⁹Si NMR, IR, GPC, TGA and elemental analysis. ¹³C and ²⁹Si NMR permit Stereochemical analysis on the microstructures of II and IV.