Synthesis of 4‐((2‐hydroxynaphthalen‐1‐yl)(aryl)methyl)‐5‐methyl‐2‐phenyl‐1H‐pyrazol‐3(2H)‐ones using nano‐Zn‐[2‐boromophenyl‐salicylaldimine‐methylpyranopyrazole]Cl2 nanoparticles

Nano‐Zn‐[2‐boromophenyl‐salicylaldimine‐methylpyranopyrazole]Cl₂ (nano‐[Zn‐2BSMP]Cl₂) as a nanoparticle Schiff base complex and a catalyst was introduced for the solvent‐free synthesis of 4‐((2‐hydroxynaphthalen‐1‐yl)(aryl)methyl)‐5‐methyl‐2‐phenyl‐1H‐pyrazol‐3(2H)‐ones by the multicomponent condensation reaction of various aromatic aldehydes, β‐naphthol, ethyl acetoacetate, and phenyl hydrazine at room temperature.     

Synthesis of 4‐Aryl‐3‐Methyl‐1‐Phenyl‐1H‐Benzo[h]Pyrazolo[3,4‐b]Quinoline‐5,10‐diones Using Diammonium Hydrogen Phosphate as an Efficient and Versatile Catalyst in Water

A simple and efficient synthesis of 4‐aryl‐3‐methyl‐1‐phenyl‐1H‐benzo[h]pyrazolo[3,4‐b]quinoline‐5,10‐diones has been accomplished by the one‐pot condensation reaction of 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5‐amine, aldehydes and 2‐hydroxynaphthalene‐1,4‐dione in water in the presence of diammonium hydrogen phosphate.     

Optical Resolution of 5‐Oxo‐1‐Phenyl‐Pyrazolidine‐3‐Carboxylic Acid as a New Organocatalyst for Organic Reactions

Optical resolution of racemic 5‐oxo‐1‐phenyl‐pyrazolidine‐3‐carboxylic acid 2 with L‐amino acid methyl ester via the diastereomers formation was investigated. Treatment of racemic 5‐oxo‐1‐phenyl‐pyrazolidine‐3‐carboxylic acid 2 with L‐valine methyl ester gave diastereomers with a total yield of 86%. The diastereomeric dipeptides can be easily separated by flash column chromatography. Acidic cleavage of the derived diastereomers gave both the optically pure (+)‐(R)‐ and (‐)‐(S)‐5‐oxo‐1‐phenyl‐pyrazolidine‐3‐carboxylic acid ((+)‐(R)‐ 2 and (‐)‐(S)‐ 2 ) with a total yield of 94% and 95%, respectively.     

Design,Synthesis, and Evaluation of 3‐((4‐(t‐Butyl)‐2‐(2‐benzylidenehydrazinyl)thiazol‐5‐yl)methyl)quinolin‐2(1H)‐ones as Neuraminidase Inhibitors

A series of novel 3‐((4‐(t‐butyl)‐2‐(2‐benzylidenehydrazinyl)thiazol‐5‐yl)methyl)quinolin‐2(1H)‐ones ( 7a – 7z ) were designed, synthesized and evaluated for their ability of inhibiting neuraminidase (NA) of in?uenza H1N1 virus. Some compounds displayed moderate influenza NA inhibitory activity. Compound 7l with the scaffold of 2‐(2‐(2‐methoxybenzylidene)hydrazinyl)thiazole was the best one, exhibiting moderate NA inhibitory activity with IC₅₀ of 44.66 µmol/L. Structure‐activity relationship showed that compounds with methoxy or hydroxy groups at the ortho position, fluorine and nitro groups at the meta position and chlorine and bromine groups at the para position of phenyl ring were more active. Docking study indicated that compound 7l has important interactions with some key residues (including Asp151, Glu119, Arg292, Tyr406, and Asn347) and binds to 430‐cavity adjacent to NA active site.     

A Facile Synthesis of 1‐Substituted 3‐Alkoxy‐1H‐isoindoles Based on the Reaction of 2‐(Dialkoxymethyl)phenyllithiums with Nitriles,Followed by Acid‐Catalyzed Cyclization

A two‐step synthesis of 1‐substituted 3‐alkoxy‐1H‐isoindoles 4 has been developed. Thus, the reaction of 2‐(dialkoxymethyl)phenyllithium compounds, which are easily generated in situ by Br/Li exchange between 1‐bromo‐2‐(dialkoxymethyl)benzenes 1 and BuLi in THF at ?78°, with nitriles afforded [2‐(dialkoxymethyl)phenyl]methanimines 2 , which were treated with a catalytic amount of TsOH?H₂O in refluxing CHCl₃ to give the desired products in reasonable yields. Similarly, 3‐aryl‐1‐ethoxy‐1‐methyl‐1H‐isoindoles 7 have been prepared starting from 1‐bromo‐2‐(1,1‐diethoxyethyl)benzenes 5 .     

A Convenient Method for the Preparation of 1,5‐Diaryl‐3‐(arylamino)‐1H‐pyrrol‐2(5H)‐ones

A simple and eco‐friendly method for the preparation of 1,5‐diaryl‐3‐(arylamino)‐1H‐pyrrol‐2(5H)‐ones via the cyclo‐condensation reaction of aldehydes, amines and ethyl pyruvate in the presence of silica supported ferric chloride (SiO₂‐FeCl₃) as reusable heterogeneous catalyst is described. The present methodology offers several advantages such as excellent yields, simple procedure and short reaction times.     

Effect of Medium Acidity and Photostability of 3‐(4‐Dimethylamino‐phenyl)‐1‐(2,5‐dimethyl‐thiophen‐3‐yl)‐propenone (DDTP): A New Green Emitting Laser Dye

On the line of a previous work on the spectral properties of some of heteroaryl chalcone, the effect of medium acidity and photoreactivity of 3‐(4‐dimethylamino‐phenyl)‐1‐(2,5‐dimethyl‐thiophen‐3‐yl)‐propenone (DDTP) has been investigated in dimethylformamide and in chloromethane solvents such as methylenechloride, chloroform and carbon tetrachloride. The dye solution (ca. 5×10⁻⁴ mol·L⁻¹ in DMF) gives a good laser emission in the range 470–560 nm with emission maximum at 515 nm upon pumping by nitrogen laser (λ_ex=337.1 nm). The laser parameters such as gain coefficient (α), emission cross section (δ_e) and half life energy (E_1/2) at maximum laser emission are also determined.     

Synthesis of 1,3‐Dihydro‐3‐oxo‐2‐benzofuran‐1‐carboxylates via Intramolecular Cyclization of 2‐[2‐(Dimethoxymethyl)phenyl]‐ 2‐hydroxyalkanoates Followed by Oxidation

A novel and efficient method for the preparation of 1,3‐dihydro‐3‐oxo‐2‐benzofuran‐1‐carboxylates 4 under mild conditions has been developed. Thus, the reaction of [2‐(dimethoxymethyl)phenyl]lithiums, generated easily from 1‐bromo‐2‐(dimethoxymethyl)benzenes 1 , with α‐keto esters gives the corresponding 2‐[2‐(dimethoxymethyl)phenyl]‐2‐hydroxyalkanoates 2 . The TsOH‐catalyzed cyclization of these hydroxy acetals is followed by the oxidation of the resulting cyclic acetals 3 with PCC to give the desired products in satisfactory yields. The reaction of [2‐(dimethoxymethyl)‐4,5‐dimethoxyphenyl]lithium with (MeOC?O)₂, followed by treatment with NaBH₄ or organolithiums, affords 2‐[2‐(dimethoxymethyl)‐4,5‐dimethoxyphenyl]‐2‐hydroxyalkanoates 6 , which can similarly be transformed into the corresponding 1,3‐dihydro‐3‐oxo‐2‐benzofuran‐1‐carboxylates 7 in reasonable yields.     

Synthesis and Antifungal Activities of ω‐[4‐Aryl‐5‐(1‐phenyl‐5‐methyl‐1,2,3‐triazol‐4‐yl)‐1,2,4‐triazol‐3‐thio]‐ω‐(1H‐1,2,4‐triazol‐1‐yl)acetophenones

New 4‐aryl‐5‐(1‐phenyl‐5‐methyl‐1,2,3‐triazol‐4‐yl)‐1,2,4‐triazol‐3‐thiones 3 have been synthesized by the intramolecular cyclization of 4‐aryl‐1‐(1‐phenyl‐5‐methyl‐1,2,4‐triazol‐4‐formyl)thiosemicarbazides 2 with an 8% NaOH solution, and then 3 reacted with ω‐bromo‐ω‐(1H‐1,2,4‐triazol‐1‐yl)acetophenone to afford ω‐[4‐aryl‐5‐(1‐phenyl‐5‐methyl‐1,2,3‐triazol‐4‐yl)‐1,2,4‐triazol‐3‐thio]‐ω‐(1H‐1,2,4‐triazol‐1‐yl)‐acetophenones 4 . The preliminary biological test showed that the representative compounds possess some anti fungal activities.     

Synthesis and Herbicidal Activity of Novel N‐(2‐Fluoro‐5(3‐methyl‐2,6‐dioxo‐4‐(trifluoromethyl)‐2,3‐dihydro‐pyrimidin‐1(6H)‐yl)phenyl)‐2‐phenoxyacetamide Derivatives

Thirteen novel N‐(2‐fluoro‐5‐(3‐methyl‐2,6‐dioxo‐4‐(trifluoromethyl)‐2,3‐dihydropyrimidin‐1(6H)‐yl)phenyl)‐2‐phenoxy)acetamides were designed and synthesized utilizing 4‐fluoro‐aniline and ethyl 3‐amino‐4,4,4‐trifluoro‐but‐2‐enoate as starting materials. The chemical structures of all compounds were confirmed by ¹H NMR, IR, mass spectrum and elemental analyses. Subsequently, the herbicidal activities of the as‐prepared compounds were evaluated in the greenhouse. Bioassay results indicated that most of compounds had better herbicidal activities against dicotyledonous weeds. Among all the tested compounds, compounds 4a – 4i showed good herbicidal activities at both pre‐emergence and post‐emergence treatment against two or three kinds of dicotyledonous weeds, such as Abutilon theophrasti Medic, Amaranthus ascendens L, and Chenopodium album L at the dosage of 75 g ai/ha.     

Synthesis of Some Heterocyclic Compounds from 1H‐Indole‐2,3‐Dione: A Direct One‐Pot Synthesis of Spiro Indolone Derivatives

Some spiro indolone derivatives 5_a,b and 6 were synthesized through one‐pot synthesis via the ternary condensation of 1H‐indole‐2,3‐dione 1 , 3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐one 2 and active methylenes, namely malononitrile, ethyl cyanoacetate 4_a,b and pyrazolone 2 , respectively. The same derivatives can be obtained via other methods, through reactions of 3‐[3‐methyl‐5‐oxo‐1‐phenyl‐1,5‐dihydro‐pyrazol‐(4Z)‐ylidene]‐1,3‐dihydro‐indol‐2‐one 3 with the corresponding active methylenes. Reaction of 3 with amines and with ethyl vinyl ether was studied.     

邻-(N-芳酰基-N-甲氨基苯)-二硫化合物的合成：通过N-甲基-2-单芳基苯并噻唑啉在溶剂中的自发偶联反应和它们的血管内皮生长因子抑制活性

N-甲基-2-单芳基苯并噻唑啉 (1) 在固体状态时可以稳定地储藏在空气中。但是,它们在不同溶剂中却表现出了不同的行为。在醇溶液或二甲亚砜-水的体系中,1相对稳定;而在其它有机溶剂如：丙酮,氯仿,二氯甲烷和乙酸乙酯等溶剂中,会发生自发偶联反应生成相应的邻-(N-芳酰基-N-甲氨基苯)-二硫化合物 (2)。对这些新的化合物 (1) 和 (2) 进行了体外人乳腺癌细胞 (MDA-MB-231) 血管内皮生长因子靶点筛选,大部分化合物都表现出了抑制活性。实验结果表明这两类化合物 (1) 和 (2) 作为血管内皮生长因子抑制剂值得进行深入研究。     

An Efficient One‐pot Synthesis of Pyrazolone Derivatives Promoted by Acidic Ionic Liquid

A new class of pyrazolone derivatives has been isolated in good to excellent yields from the 2:1 condensation reaction between 3‐methyl‐1‐phenyl‐5‐pyrazolone and arylaldehydes in the presence of ionic liquid [HMIM]HSO₄. The compounds were characterised by their IR, NMR spectra, MS and elemental analyses. The important features of the methodology are a wide application range of substrates, higher yields and shorter reaction time.     

Synthesis and Cytotoxicity of 6‐Pyrrolidinyl‐2‐(2‐Substituted Phenyl)‐4‐Quinazolinones

In our continuing search for potential anticancer candidates, 2‐(3‐methoxyphenyl)‐6‐pyrrolidinyl‐4‐quinazolinone ( JJC‐1 ) was selected as the lead compound. Starting 5‐pyrrolidinyl‐2‐aminobenzamide was prepared using standard methodology from 5‐chloro‐2‐nitrobenzoic acid by reaction with SOCl₂, NH₃, pyrrolidine, and H₂. The starting benzamide then was reacted with 2‐substituted benzaldehyde or benzoyl chloride in N,N‐dimethylacetamide (DMAC) in the presence of NaHSO₃ at 150 °C. Thermal cyclodehydration/dehydrogenation gave the target 6‐pyrrolidinyl‐2‐(2‐substituted phenyl)‐4‐quinazolinones ( 15–22 ). These target compounds were assayed for their cytotoxicity in vitro against six cancer cell lines, including human monocytic leukemia cells (U937), mouse monocytic leukemia cells (WEHI‐3), human hepatoma cells (HepG2, Hep3B) and human lung carcinoma cells (A549, CH27). Most of them exhibited significant cytotoxic effect toward U937 and WEHI‐3 cells, with EC₅₀ values ranging from 0.30 to 10.10 μM. Compound 19 was investigated further for its action mechanisms. Preliminary findings indicated that compound 19 induced G2/M arrest and apoptosis on U937 cells.     

Organosoluble polyimides and copolyimides based on 1,1‐bis[4‐(4‐aminophenoxy)phenyl]‐1‐phenylethane and aromatic dianhydrides

1,1‐Bis[4‐(4‐aminophenoxy)phenyl]‐1‐phenylethane (BAPPE) was prepared through nucleophilic substitution reaction of 1,1‐bis(4‐hydroxyphenyl)‐1‐phenylethane and p‐chloronitrobenzene in the presence of K₂CO₃ in N,N‐dimethylformamide, followed by catalytic reduction with hydrazine and Pd/C. Novel organosoluble polyimides and copolyimides were synthesized from BAPPE and six kinds of commercial dianhydrides, including pyromellitic dianhydride (PMDA, I_a ), 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA, I_b ), 3,3′,4,4′‐ biphenyltetracarboxylic dianhydride (BPDA, I_c ), 4,4′‐oxydiphthalic anhydride (ODPA, I_d ), 3,3′,4,4′‐diphenylsulfonetetracarboxylic dianhydride (DSDA, I_e ) and 4,4′‐hexafluoroisopropylidenediphthalic anhydride (6FDA, I_f ). Differing with the conventional polyimide process by thermal cyclodehydration of poly(amic acid), when polyimides were prepared by chemical cyclodehydration with N‐methyl‐2‐pyrrolidone as used solvent, resulted polymers showed good solubility. Additional, I_a,b were mixed respectively with the rest of dianhydrides (I_c–f) and BAPPE at certain molar ratios to prepare copolyimides with arbitrary solubilities. These polyimides and copolyimides were characterized by good mechanical properties together with good thermal stability. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2082–2090, 2000     

Transformations of Methyl 2‐[(E)‐2‐(Dimethylamino)‐1‐(methoxycarbonyl)ethenyl]‐1‐methyl‐1H‐indole‐3‐carboxylate

A simple and efficient synthesis of novel 2‐heteroaryl‐substituted 1H‐indole‐2‐carboxylates and γ‐carbolines, compounds 1 – 3 , from methyl 2‐(2‐methoxy‐2‐oxoethyl)‐1‐methyl‐1H‐indole‐3‐carboxylate ( 4 ) by the enaminone methodology is presented.     

Facile and Selective Synthesis of 4‐Methyl‐ and 4‐Phenylthiosemicarbazide (=N‐Methyl‐ and N‐Phenylhydrazinecarbothioamide) Derivatives of Benzil (=1,2‐Diphenylethane‐1,2‐dione)

A selective synthesis of 4‐methylthiosemicarbazide (=N‐methylhydrazinecarbothioamide; 4a ) derivatives by reaction with benzil (=1,2‐diphenylethane‐1,2‐dione; 3 ) is described. The reaction conditions determined the condensation product formed. The most important factor was the acid used: in the presence of conc. HCl solution, the open‐chain 2 : 1 compound 1a was exclusively obtained, whereas in the presence of 2M HCl, the cyclic 1 : 1 condensation product 2a was formed. The alcohol used, the presence of H₂O, and the time of heating were additional crucial factors. The new cyclic compound 2a with a MeO group was exclusively formed when working under high‐dilution conditions. The reaction with the 4‐phenyl derivative 4b gave new cyclic compounds as the major products under all conditions used (Scheme).     

An Efficient Stereoselective Total Synthesis of Bioactive (3R,5R)‐1‐(4‐Hydroxyphenyl)‐7‐phenylheptane‐3,5‐diol via Asymmetric Aldol Reaction

An efficient stereoselective total synthesis of (3R,5R)‐1‐(4‐hydroxyphenyl)‐7‐phenylheptane‐3,5‐diol ( 1 ) is reported based on the Mukaiyama aldol reaction. The total synthesis of compound 1 was accomplished with 30% overall yield in simple eight steps from commercially available trans‐cinnamaldehyde.     

Structure and Bonding in Bis(1‐naphthyl) Diselenide and Bis{[2‐(N,N‐dimethylamino)methyl]phenyl} Tetraselenide,and Their Brominated Derivatives

The formation and crystal structures of bis(1‐naphthyl) diselenide ( 1 ) and bis{[2‐(N,N‐dimethylamino)methyl]phenyl} tetraselenide ( 2 ) are described. Whereas 1 can be produced in good yields, 2 is formed only as a minor product together with the known main product, bis{[2‐(N,N‐dimethylamino)methyl]phenyl} diselenide. The composition of the reaction mixture is semi‐quantitatively estimated by ⁷⁷Se NMR spectroscopy and DFT calculations. The effect of the n²→σ*(Se–Se) and π→σ*(Se–Se) secondary bonding interactions on the Se–Se bonds is discussed both by DFT calculations and comparison with literature, as available. The bromination of 1 yields monomeric (1‐naphthyl)selenenyl bromide ( 3 ) in good yields. That of the reaction mixture of (C₆H₄CH₂NMe₂)Se_x (x = 2–4) and Se₈ afforded (C₆H₄CH₂NMe₂H)₂[SeBr₄] ( 4 ) and (C₆H₄CH₂NMe₂H)₂[SeBr₆] ( 5 ) in addition to (C₆H₄CH₂NMe₂)SeBr, which has been previously reported.     

Heterocyclic Systems Containing Bridged Nitrogen Atom: Synthesis and Antibacterial Activity of 3‐(2‐Phenylquinolin‐4‐yl)/3‐(1‐p‐Chlorophenyl‐5‐methyl‐1,2,3‐triazol‐4‐yl)‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazine Derivatives

The condensation of 4‐amino‐5‐mercapto‐3‐(2‐phenylquinolin‐4‐yl)/3‐(1‐p‐chlorophenyl‐5‐methyl‐1,2,3‐triazol‐4‐yl)‐1,2,4‐triazoles 1a‐b with chloroacetaldehyde 2a‐b , ω‐bromo‐ω‐(1H‐1,2,4‐triazol‐1‐yl)acetophenone 3a‐b , chloranil 4a‐b , 2‐bromocyclohexanone 5a‐b , 2,4′‐dibromoacetophenone 6a‐b and 2‐bromo‐6′‐methoxy‐2′‐acetonaphthone 7a‐b are described. The structures of the compounds synthesized were confirmed by elemental analyses, IR, 1H NMR and mass spectra. The antibacterial activities were also evaluated.