Synthesis of through‐space conjugated polymers containing [2.2]paracyclophane and thieno[3,4‐b]pyrazine in the main chain

We synthesized through‐space conjugated polymers with [2.2]paracyclophane and thieno[3,4‐b]pyrazine units in the main chain by the Sonogashira–Hagihara coupling reaction. The obtained polymers were soluble in common organic solvents, and homogeneous thin films were readily obtained from the polymer solutions by spin‐coating techniques. The polymers exhibited the extension of the conjugation length via the through‐space interaction. The polymers showed orangish‐red emission with peak maxima of around 610 nm in diluted solutions and their thin films, which were derived from the thieno[3,4‐b]pyrazine moieties. The optical and electrochemical behaviors of the polymers containing pseudo‐para‐ and pseudo‐ortho‐linked [2.2]paracyclophane were identical. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2009     

A New Four‐Component Reaction for the Synthesis of Spiro[4H‐indeno[1,2‐b]pyridine‐4,3′‐[3H]indoles]

A new four‐component synthesis of spiro[4H‐indeno[1,2‐b]pyridine‐4,3′‐[3H]indoles] and spiro[acenaphthylene‐1(2H),4′‐[4H‐indeno[1,2‐b]pyridines] by the reaction of indane‐1,3‐dione, 1,3‐dicarbonyl compounds, isatins (=1H‐indole‐2,3‐diones) or acenaphthylene‐1,2‐dione, and AcONH₄ in refluxing toluene in the presence of a catalytic amount of pyridine is reported.     

One‐pot Combinatorial Synthesis of Benzo[4,5]imidazo‐[1,2‐a]thiopyrano[3,4‐d]pyrimidin‐4(3H)‐one Derivatives

A series of novel fused tetracyclic benzo[4,5]imidazo[1,2‐a]thiopyrano[3,4‐d]pyrimidin‐4(3H)‐one derivatives were synthesized via the reaction of aryl aldehyde, 2H‐thiopyran‐3,5(4H,6H)‐dione, and 1H‐benzo[d]imidazol‐2‐amine in glacial acetic acid. This protocol features mild reaction conditions, high yields and short reaction time.     

Reactions of Hydrazonoyl Halides 571: Reactions of 1‐Bromo‐2‐(5‐Chlorobenzofuranyl)Ethanedione‐1‐Phenylhydrazone

Pyrrolo[3,4‐c]pyrazole‐4,6‐diones, pyrazoles, pyrazolo[3,4‐d]pyridazines, and pyrazolo[3,4‐d]pyrimidines were prepared via 1‐bromo‐2‐(5‐chlorobenzofuran‐2‐yl)ethanedione‐1‐phenylhydrazone with N‐arylmalemides and active methylene. All newly synthesized compounds were confirmed by elemental analysis and spectral data.     

A Novel Route to 1‐Substituted 3‐(Dialkylamino)‐9‐oxo‐9H‐indeno[2,1‐c]pyridine‐4‐carbonitriles

Heptalenecarbaldehydes 1 / 1′ as well as aromatic aldehydes react with 3‐(dicyanomethylidene)‐indan‐1‐one in boiling EtOH and in the presence of secondary amines to yield 3‐(dialkylamino)‐1,2‐dihydro‐9‐oxo‐9H‐indeno[2,1‐c]pyridine‐4‐carbonitriles (Schemes 2 and 4, and Fig. 1). The 1,2‐dihydro forms can be dehydrogenated easily with KMnO₄ in acetone at 0° (Scheme 3) or chloranil (=2,3,5,6‐tetrachlorocyclohexa‐2,5‐diene‐1,4‐dione) in a ‘one‐pot’ reaction in dioxane at ambient temperature (Table 1). The structures of the indeno[2,1‐c]pyridine‐4‐carbonitriles 5′ and 6a have been verified by X‐ray crystal‐structure analyses (Fig. 2 and 4). The inherent merocyanine system of the dihydro forms results in a broad absorption band in the range of 515–530 nm in their UV/VIS spectra (Table 2 and Fig. 3). The dehydrogenated compounds 5, 5′ , and 7a – 7f exhibit their longest‐wavelength absorption maximum at ca. 380 nm (Table 2). In contrast to 5 and 5′, 7a – 7f in solution exhibit a blue‐green fluorescence with emission bands at around 460 and 480 nm (Table 4 and Fig. 5).     

New Types of Planar Chiral [2.2]Paracyclophanes and Construction of One‐Handed Double Helices

New types of planar chiral (R_p)‐ and (S_p)‐4,7,12,15‐tetrasubstituted [2.2]paracyclophanes were synthesized from racemic 4,12‐dihydroxy[2.2]paracyclophane as the starting compound. Regioselective dibromination and transformation afforded a series of planar chiral (R_p)‐ and (S_p)‐4,7,12,15‐tetrasubstituted [2.2]paracyclophanes, which can be used as chiral building blocks. In this study, left‐ and right‐handed double helical structures were constructed via chemoselective Sonogashira–Hagihara coupling. The double helical compounds were excellent circularly polarized luminescence (CPL) emitters with large molar extinction coefficients, good photoluminescence quantum efficiencies, and large CPL dissymmetry factors.     

Synthesis and Herbicidal Activity of 5‐Alkyl(aryl)‐3‐[(3‐trifluoromethyl)anilino]‐4,5‐dihydro‐1H‐pyrazolo[4,3‐d]pyrimidin‐4‐imines

A series of novel 5‐alkyl(aryl)‐3‐[(3‐trifluoromethyl)anilino]‐4,5‐dihydro‐1H‐pyrazolo[4,3‐d]pyrimidin‐4‐imines were designed and synthesized by the multistep reactions. 1 reacted with 3‐(trifluoromethyl)aniline to obtain N,S‐acetals 2 in the presence of 10 mol% DBU. 2 reacted with hydrazine to form 5‐amino‐3‐[(3‐trifluoromethyl)anilino]‐1H‐pyrazol‐4‐ nitrile 3 , the target compounds 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , 5l , 5m were obtained by the reaction of 3 with triethyl orthoformate followed by the cyclization of 4 with various amines. Their structures were confirmed by IR, ¹H NMR, EI‐MS, and elemental analyses. The preliminary bioassay indicated that some of them displayed moderate herbicidal activity against dicotyledonous weed Brassica campestris L at the concentration of 100 mg/L. For example, compounds 5f , 5g , 5h , and 5j possessed 60.1%, 63.4%, 67.1%, and 61.3% inhibition against Brassica campestris L at the concentration of 100 mg/L.     

Synthesis and properties of new polyamides derived from 2,2‐bis[4‐[2‐(4‐aminophenoxy)ethoxy]phenyl]sulfone by direct polycondensation

A series of new polyamides containing both sulfone and oxyethylene moieties in the polymer chain was prepared by the direct polycondensation of the diamine monomer 2,2‐bis[4‐[2‐(4‐aminophenoxy)ethoxy]phenyl]sulfone (BAEPS) and various aromatic dicarboxylic acids in N‐methyl‐2‐pyrrolidinone (NMP) using triphenyl phosphite and pyridine as condensing agents. Polymers were produced with inherent viscosities of 0.30–0.60 dl/g and identified by elemental analysis, and infrared and nuclear magnetic resonance spectra. Most of the polymers were readily dissolved in polar solvents such as NMP, dimethylsulfoxide, N,N‐dimethylacetamide, N,N‐dimethylformamide and m‐cresol at room temperature. Polymers containing rigid and symmetric p‐phenylene, naphthalene and p‐biphenylene moieties revealed a crystalline nature and showed no solubility in organic solvents. These polyamides had 10% weight loss temperatures ranging between 423 and 465 °C in nitrogen atmosphere and glass transition temperatures between 170 and 305 °C. The polymers with crystallinity nature exhibited melting endotherms (T_m) below 386 °C in differential scanning calorimetry trace. Copyright © 1999 John Wiley & Sons, Ltd.     

A Facile Synthesis of Aryl‐Substituted Hydrazono‐Pyrazolyl[1,2,4]triazolo[3,4‐b][1,3,4][thiadiazol]‐coumarin Derivatives

Some inimitable and therapeutic coumarin‐substituted fused[1,2,4]triazolo‐[3,4‐b][1,3,4]thiadizole derivatives were synthesized by the cyclocondensation reaction of 2‐oxo‐2H‐chromene‐3‐carboxylic acid ( 1 ) and 4‐amino‐5‐hydrazinyl‐4H‐[1,2,4]‐triazole‐3‐thiol ( 2 ) by using phosphorous oxychloride as a cyclizing agent. This cyclized intermediate 3‐(3‐hydrazino‐[1,2,4]triazolo[3,4‐b][1,3,4]thiadiazol‐6‐yl)‐chromen‐2‐one ( 3 ) later condensation with various ethyl 2‐(2‐arylhydrazono)‐3‐oxobutanoates ( 4 ) in NaOAc/MeOH under reflux conditions afforded the corresponding new series of aryl‐substituted hydrazono‐pyrazolyl‐[1,2,4]triazolo[3,4‐b][1,3,4][thiadiazol]‐coumarin derivatives ( 5 ) in good to excellent yields. The structures of newly synthesized compounds were established on the basis of elemental analysis, IR, ¹H NMR and mass spectroscopic studies.     

Unexpected Reaction Course of 3‐Amino‐5‐aryl‐1H‐pyrazoles with Dialkyl Dicyanofumarates

On treatment of 3‐amino‐5‐aryl‐1H‐pyrazoles 1 with dialkyl dicyanofumarates (=(E)‐but‐2‐enedioates) 4 in boiling 1,2‐dichloroethane, two competitive reactions occurred leading to 3‐aryl‐5‐cyano‐6,7‐dihydro‐6‐oxo‐1H‐pyrazolo[3,4‐b]pyridine‐4‐carboxylates 10 and 7‐amino‐2‐arylpyrazolo[1,5‐a]pyrimidine‐5,6‐dicarboxylates 11 . In DMF at room temperature, as well as at 100°, only compounds 10 were isolated. The formation of the major products of type 10 was rationalized via Michael addition of 1 as a C(4)‐nucleophile onto 4 , followed by HCN elimination and lactamization. On the other hand, the minor products 11 result from a Michael addition of 1 onto 4 via the NH₂ group, and subsequent HCN elimination and cyclization. The structures of the products have been established by X‐ray crystallography.     

Synthesis of New Furo[3,4‐b]quinolin‐1(3H)‐one Scaffolds Derived from γ‐Lactone‐Fused Quinolin‐4(1H)‐ones

In the context of our aim of discovering new antitumor drugs among synthetic γ‐lactone‐ and γ‐lactam‐fused 1‐methylquinolin‐4(1H)‐ones, we developed a rapid access to 5‐methyl‐1,3‐dioxolo[4,5‐g]furo[3,4‐b]quinoline‐8,9(5H,6H)‐dione ( 9 ) exploiting the γ‐lactone‐fused chloroquinoline 10 previously synthesized in our laboratory (Scheme 1). We also elaborated efficient synthetic methods allowing for a rapid access to two nonclassical bioisosteres of 9 , i.e., a deoxy and a carba analogue. The deoxy analogue 11 was prepared in two steps from the γ‐lactone‐fused quinoline 13 which was also the synthetic precursor of 10 (Scheme 1). The carba analogue 6,9‐dihydro‐5‐methyl‐9‐methylene‐1,3‐dioxolo[4,5‐g]furo[3,4‐b]quinolin‐8(5H)‐one ( 12 ) was easily prepared by HCl elimination from the 9‐(chloromethyl)dioxolofuroquinoline 15 , which was obtained via a three‐component one‐pot reaction from N‐methyl‐3,4‐(methylenedioxy)aniline (=N‐methyl‐1,3‐benzodioxol‐5‐amine; 16 ), commercially available chloroacetaldehyde, and tetronic acid ( 17 ) (Scheme 2).     

A Facile One‐Pot Synthesis of Functionalized 1,5‐Dihydro‐2H‐[1]benzopyrano[2,3‐b]pyridin‐5‐ones

The highly reactive 1 : 1 intermediate generated in the reaction between dialkyl acetylenedicarboxylate (=but‐2‐ynedioic acid dialkyl ester) 4 and triphenylphosphine was trapped by 2‐amino‐4‐oxo‐4H‐1‐benzopyran‐3‐carboxaldehydes 5 to yield highly functionalized dialkyl‐1,5‐dihydro‐5‐oxo‐1‐phenyl‐2H‐[1]benzopyrano[2,3‐b]pyridine‐2,3‐dicarboxylates in high yield.     

Synthesis and Fungicidal Activity of (E)‐5‐[1‐(2‐Oxo‐1‐oxaspiro[4,5]dec/non‐3‐en‐3‐yl)ethylidene]‐2‐aminoimidazolin‐4‐one Derivatives

The novel fungicidal agents, (E )‐5‐[1‐(2‐oxo‐1‐oxaspiro[4,5]dec/non‐3‐en‐3‐yl)ethylidene]‐2‐aminoimidazolin‐ 4‐one derivatives, were designed and synthesized in moderate to excellent yields in four steps using α ‐hydroxyketone and diketene as raw materials and characterized by HR‐ESI‐MS , ¹H NMR and X‐ray diffraction. The preliminary bioassay showed that some of these compounds, such as 5e , 6a , 6e , and 7 h exhibit 87.8%, 91.3%, 89.9% and 87.8% inhibition rates against Sclerotinia scleotiorum , 3b , 3c , 4c and 7 h exhibit 96.4%, 92.5%, 90.3% and 76.9% inhibition rates against Phytophthora capsici at the concentration of 50 µg/mL , respectively. These compounds exhibited significant fungicidal activities against S. scleotiorum and P. capsici with EC₅₀ values of 2.56–11.60 µg/mL , and compounds 6e and 7 h exhibited weak inhibition against the spore germination of S. scleotiorum , while the spore germination of P. capsici was strongly inhibited by compound 7 h solution. Scanning electron microscopy (SEM ) and transmission electron microscopy (TEM ) observation indicated that compound 7 h had a significant impact on the structure and function of the hyphal cell wall of P. capsici mycelium.     

Synthesis and Structure of 2‐Substituted Thieno[3′,2′:5,6]pyrido[4,3‐d]pyrimidin‐4(3H)‐one Derivatives

A series of new 2‐substituted 3‐(4‐chlorophenyl)‐5,8,9‐trimethylthieno[3′,2′: 5,6]pyrido[4,3‐d]pyrimidin‐4(3H)‐ones 8 were synthesized via an aza‐Wittig reaction. Phosphoranylideneamino derivatives 6a or 6b reacted with 4‐chlorophenyl isocyanate to give carbodiimide derivatives 7a or 7b , respectively, which were further treated with amines or phenols to give compounds 8 in the presence of a catalytic amount of EtONa or K₂CO₃. The structure of 2‐(4‐chlorophenoxy)‐3‐(4‐chlorophenyl)‐5,8,9‐trimethylthieno[3′,2′: 5,6]pyrido[4,3‐d]pyrimidin‐4(3H)‐one ( 8j ) was comfirmed by X‐ray analysis.     

Synthesis and Herbicidal Activity of Muti‐Substituted Pyrido[4,3‐d]pyrimidin‐4‐ones

A series of novel muti‐substituted pyrido[4,3‐d]pyrimidin‐4‐one derivatives 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , 5l were designed and synthesized by the muti‐step reaction. N,S‐acetal 1 reacted with acetyl acetamide in the presence of zinc nitrate to obtain muti‐substituted pyridine 2 , which reacted with triethyl orthoformate to give 8‐cyano‐5‐methyl‐7‐methylthio‐pyrido[4,3‐d]pyrimidin‐4‐one 3 ; the target compounds 5 were obtained in good yields by the oxidation of 3 with H₂O₂ in a catalytic amount of sodium tungstate then by the substitution with various substituted phenols. Their structures were confirmed by IR, ¹H NMR, EI‐MS, and elemental analyses. The preliminary bioassay indicated that some of them displayed moderate herbicidal activity against dicotyledonous weed Brassica campestris L. at the concentration of 100 mg/L. For example, compounds 5a , 5f , and 5g possessed 76.0%, 62.7%, and 60.2% inhibition against B. campestris at the concentration of 100 mg/L. Moreover, 5a exhibited 58.2% inhibition against B. campestris at the concentration of 10 mg/L.     

Synthesis and Biological Activities of 7‐Arylazo‐7H‐pyrazolo[5,1‐c][1,2,4] Triazol‐6(5H)‐Ones and 7‐Arylhydrazono‐7H‐[1,2,4]triazolo[3,4‐b] [1,3,4]thiadiazines

Two series of 7‐arylazo‐7H‐3‐(2‐methyl‐1H‐indol‐3‐yl)pyrazolo[5,1‐c][1,2,4]triazol‐6(5H)‐ones 4 and 7‐arylhydrazono‐7H‐3‐(2‐methyl‐1H‐indol‐3‐yl)‐[1,2,4]triazolo[3,4‐b][1,3,4]thiadiazines 7 were prepared via reactions of 4‐amino‐3‐mercapto‐5‐(2‐methyl‐1H‐indol‐3‐yl)‐1,2,4‐triazole 1 with ethyl arylhydrazono‐chloroacetate 2 and N‐aryl‐2‐oxoalkanehydrazonoyl halides 5 , respectively. A possible mechanism is proposed to account for the formation of the products. The biological activity of some of these products was also evaluated.     

Synthesis of novel mono- and diaryl-substituted [2.2]paracyclophanes

The cross-coupling reactions of 4-bromo[2.2]paracyclophane withp-tolylmagnesium bromide in the presence of various palladium and nickel complexes have been studied. It was found that [1,1 -bis(diphenylphosphinoferrocene)]palladium dichloride (PdCl₂ · dppf) shows the highest catalitic activity in this reaction. A series of new mono- and diaryl [2.2]paracyclophane derivatives with various substituents in the arene ring have been synthesized using this catalyst. It was shown that it is possible to cross-couple organozinc [2.2]paracyclophane derivatives with aromatic bromides. The composition and structure of the compounds obtained have been established on the basis of elemental analysis and spectral data. Some correlations between the structure and spectral parameters of mono- and diarylsubstituted [2.2]paracyclophanes have been found.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1081–1085, June, 1994.The present work was financially supported by the Russian Foundation for Basic Research (Project No. 93-03-5246).The authors wish to express their gratitude to Prof. N. A. Bumagin for his scientific interest and helpful discussions.     

Tetrakis(bicyclo[2.2.2]oct‐2‐ene)‐Fused Calix[4]pyrrole

Tetrakis(bicyclo[2.2.2]oct‐2‐ene)‐fused calix[4]pyrrole, 5 , was obtained starting from (E)‐1,2‐bis(phenylsulfonyl)ethylene. This new calixpyrrole derivative is the prospective precursor of tetrabenzocalix[4]pyrrole, a potential ion‐pair receptor and an attractive species as a possible deep‐walled ‘molecular container’.     

Synthesis of Some Novel 3,6‐Bis(1,2,3‐triazolyl)‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazole Derivatives

The cyclization of 1‐amino‐2‐mercapto‐5‐[1‐(4‐ethoxyphenyl)‐5‐methyl‐1,2,3‐triazol‐4‐yl]‐1,3,4‐triazole which was synthesized from p‐ethoxyaniline with various triazole acid in absolute phosphorus oxychloride yields 3,6‐bis(1,2,3‐triazolyl)‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazole derivatives 9a?j , and their structures are established by MS, IR, CHN and ¹H NMR spectral data.     

One‐Pot Synthesis of 1,4‐Oxathiino[2,3‐b]quinoxalines or ‐pyrazines from 2,3‐Dichloroquinoxaline or ‐pyrazine and 1‐Aryl‐2‐bromoalkan‐1‐ones

An efficient one‐pot synthesis of novel heterocyclic derivatives, 2‐aryl‐1,4‐oxathiino[2,3‐b]quinoxalines or ‐pyrazines 5 , via the reaction of 2,3‐dichloroquinoxaline or ‐pyrazine with Na₂S?9 H₂O, and subsequent treatment of the resulting 2‐chloro‐3‐sodiosulfanylquinoxaline or ‐pyrazine 2 with 1‐aryl‐2‐bromo‐1‐alkanones and then NaH under mild conditions is described.