Synthesis, Reactions, and Anti-inflammatory Activity of Heterocyclic Systems Fused to a Thiophene Moiety Using Citrazinic Acid As Synthon

Summary. A series of pyridines, pyrimidinones, and oxazinones were synthesized as anti-inflammatory agents using citrazinic acid (2,6-dihydroxyisonicotinic acid) as a starting material. Acryloyl pyridine was treated with cyanothioacetamide to give cyano pyridine-thione, which was reacted with ethyl chloroacetate to yield the corresponding amino ester. The ester was hydrolysed to the sodium salt, which was treated with acetic anhydride to afford 2-methyloxazinone, which was treated with ammonium acetate to afford 2-methylpyrimidinone followed by methylation with methyl iodide to yield 2,3-dimethylpyrimidinone. In addition, the oxazinone derivative was reacted with aniline or hydrazine hydrate to give 3-phenyl- or 3-aminopyrimidinones. The latter reacted with thiophene-2-carboxaldehyde or phenylisothiocyanate to afford Schiff’s bases or thiosemicarbazides. 3-Aminopyrimidinone was treated with phthalic anhydride or 1,2,4,5-benzenetetracarboxylic acid dianhydride or toluene-3,5-diisocyanate to afford the corresponding imide, bis-imide, and bis-semicarbazide derivatives. The pharmacological screening showed that many of these compounds have good anti-inflammatory activity comparable to Prednisolone^? as reference drug.     

Synthesis and Characterization of New Heterocyclic Compounds Containing Thienylbenzo[h]Quinoline Moiety

In this paper the reaction of 2‐(2′‐thienylmethylene)‐3,4‐dihydronaphthalen‐2(1H)‐one ( 1 ) with cyanothioacetamide gave a mixture of 3‐cyano‐5,6‐dihydro‐4‐(2′‐thienyl)‐benzo[h]quinolin‐2(1H)‐thione ( 2 ) and the related disulfide 3 . Compound 2 was reacted with some halo compounds namely; ethyl chloroacetate, chloroacetamide, chloro(N‐(p‐chlorophenyl))acetamide, N¹‐chloroacetylsulfanilamide, and 2‐chloromethyl‐1H‐benzimidazole to produce a series of 2‐(substituted)methylthio‐3‐cyano‐5,6‐dihydro‐4‐(2′‐thienyl)benzo[h]quinolines 4a , 4b , 4c , 4d , 4e and 11 . Upon heating the latter compounds with sodium ethoxide, they underwent intramolecular Thorpe–Zeigler cyclization to furnish the corresponding 2‐(substituted)‐3‐amino‐5,6‐dihydro‐4‐(2′‐thienyl)‐benzo[h]thieno[2,3‐b]quinolines 5a , 5b , 5c , 5d , 5e and 12 . (3‐Cyano‐5,6‐dihydro‐4‐(2′‐thienyl)‐benzo[h]quinolin‐2‐ylthio)acethydrazide ( 8 ) and the related isomer, 3‐amino‐5,6‐dihydro‐4‐(2′‐thienyl)thieno[2,3‐b]benzo[h]quinoline‐2‐carbohydrazide ( 9 ), were also synthesized. Most of the aforementioned compounds were used as key intermediates for synthesizing other benzo[h]quinolines, benzo[h]thieno[2,3‐b]quinolines as well as benzo[h]pyrimido[4′,5′:4,5] thieno[2,3‐b]quinolines. The structure of all synthesized compounds was confirmed by spectroscopic measurements and analytical analyses.     

Modified Kappa‐Carrageenan as a Heterogeneous Green Catalyst for the Synthesis of Nitrogen and Sulfur‐Containing Indenone‐Fused Heterocyclic Compounds

The three component reaction of aromatic aldehydes and 1,3‐indandione in the presence of 4‐amino‐6‐hydroxy‐2‐mercaptopyrimidine is catalyzed by active kappa‐carrageenan under mild conditions to afford the desired products in clean reaction profiles. The kappa carrageenan sources are bioavailable and are extracted from Chondrus crispus, a red seaweed. The catalyst could be prepared by mixing of kappa‐carrageenan in a mechanical mortar for 5 min in a simple step. Good yields with superior atom economy, green and recyclable catalyst with natural source, and simple work‐up are the main advantages of the method for the synthesis of dihydropyridopyrimidines.     

Synthesis of 2‐Oxopyridine‐Fused 1,3‐Diazaheterocyclic Compounds via a Three‐Component Reaction

An efficient and simple route for the preparation of 2‐oxopyridine‐fused 1,3‐diazaheterocyclic compounds via a three component reaction is described. It involves the reaction between alkylenediamines 1 , 1,1‐bis(methylsulfanyl)‐2‐nitroethene, and alkyl prop‐2‐ynoates 2 in refluxing THF (Table). The structures were corroborated by spectroscopic (IR, ¹H‐ and ¹³C‐NMR, and EI‐MS) and elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme).     

Synthesis and Antimicrobial Screening of Fused Heterocyclic Pyridines

In an attempt to find a new class of antimicrobial agents, a series of pyridoxazepine, pyridothiazepine, triazepine, naphthyridine, pyridopyrimidine, and other related products containing pyridine moiety were synthesized via the reaction of 2‐amino‐6‐chloro‐3,5‐dicyanopyridine 1 with nucleophilic chemical reagents. These compounds were screened for cytotoxicity and their antimicrobial activity. Most of products showed inhibitory effect.     

Synthesis of N‐Containing Heterocyclic Compounds Using Visible‐light Photoredox Catalysis

Nitrogen heterocycles represent a highly important class of compounds which are widely used in materials science, agrochemistry, and medicinal chemistry. Therefore, there is continuing interest in the development of convenient, efficient, and environmentally benign synthetic methods for the construction of nitrogen containing heterocycles. Due to its natural abundance, ease of use, and promising application in industry, the use of visible light as a driving force for chemical reactions has received considerable attention in the past few years. This account summarizes the synthesis of N‐heterocycles using visible‐light photoredox catalysis published in the last two years, according to the size and type of the formed N‐heterocyclic rings. In the context of seminal works of others in this area, a concise summary of the contributions of the authors is also offered.     

Synthesis of 1,5‐Benzodiazepine Derivatives Containing 1,2,3‐Triazole Moiety via 1,3‐Dipolar Cycloaddition Reaction

A series of 1,5‐benzodiazepine derivatives were synthesized by the reaction of 1,5‐benzodiazepine containing 1,2,3‐triazole moiety with benzohydroximinoyl chlorides at room temperature. The structural identities of these novel compounds were confirmed on the basis of IR, ¹H NMR, mass spectral and elemental analysis data, and by X‐ray crystallographic analysis of a typical example of the new class of 1,5‐benzodiazepine analogs.     

Synthesis and Reactions of Some New Heterocyclic Compounds Containing Cycloalka[e]thieno[2,3‐b]pyridine Moiety

Hydrolysis of ethyl 3-amino-4-aryl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxylates ( 3a-d) gave the corresponding o-aminocarboxylic acids 4a-d . Heating the latter compounds ( 4a-d) with acetic anhydride furnished the oxazinone derivatives 5a-d which, in turn, underwent recyclization reaction to give the corresponding pyrimidinones 6a-d upon treatment with ammonium acetate in acetic acid. Reaction of 3-amino-4-aryl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxamides ( 3f,h ) with triethyl orthoformate gave pyrimidinone derivatives 7a,b . Reaction of 3-amino-4-phenyl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxamides 3e,h with aromatic aldehydes furnished tetrahydropyridothienopyrimidinones 8a-d . Chlorination of 7a,b and 6a-d by using phosphorous oxychloride produced 4-chlorocycloalka[5′,6′]pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidine derivatives 9a-f which were used as key intermediates in the synthesis of several new cycloalkapyrido-thienopyrimidines 10a-f ˜ 14a-f . Moreover, some cycloalkapyridothienotriazinones 15a,b-17a,b were synthesized.     

Synthesis and Antitumor Activity of Some New Fused Heterocyclic Compounds

Russian Journal of General Chemistry - Reaction of thiopyrimidine derivative 3 with hydrozonoyl chlorides 4a–4e gives new fused heterocyclic compounds 7a–7e containing triazole ring....     

Synthesis of New Schiff Bases and Polycyclic Fused Thiopyranothiazoles Containing 4,6‐Dichloro‐1,3,5‐Triazine Moiety

New aromatic aldimines, isatine substituted ketimines based on (4,6‐dichloro‐1,3,5‐triazin‐2‐yl)‐hydrazine scaffold and polycyclic fused thiopyranothiazoles formed using hetero‐Diels‐Alder reactions starting from 4‐thioxo‐2‐thiazolidinones and 5‐norbornene‐2,3‐dicarboxylic acid triazino‐derivatives synthetic approach is described. The application of condensation and cyclocondensation reactions of N‐nucleophiles and carbonyl agents for synthesis a number of biologically active triazine derivatives is reported. Screening of anticancer activity in vitro yielded the most active compounds 3a , 8b , and 8f for different cell lines.     

Synthesis, Structure and Biological Activities of Novel Triazole Compounds Containing N,N-Dialkyldithiocarbamate Moiety

Introduction As an important type of fungicides, triazole compounds are highly efficient, low poisonous and inward absorbent.1-3 At present, the studies on triazole derivatives are mainly concentrated on compounds with triazole as the only active group. The report of triazole compounds that contain both triazole group and other active group in a single molecule has rarely been found. Dialkyl-substituted dithiocarbamate salts have also shown interesting biological effects.4 N,N-Dialkyldithio-…     

新型含磷拟除虫菊酯的合成及生物活性

α-羟基烃基膦酸酯;新型含磷拟除虫菊酯的合成及生物活性     

Conventional and Microwave‐Assisted Synthesis and Biological Activity Study of Novel Heterocycles Containing Pyran Moiety

Under both conventional and microwave methods, 2‐amino‐4H‐pyran‐3‐carbonitrile derivative 1 was synthesized and reacted with different reagents. Thus, 2‐amino‐4H‐pyran‐3‐carbonitrile derivative was treated with chloroacetyl chloride, phenyl isocyanate, cyanoacetic acid, benzoyl chloride, triethyl orthoformate, acetic anhydride/H₂SO₄, arylidene malononitrile, urea, and/or p‐aminosulphaguanidine producing chloroacetamide, 3‐phenylurea, cyanoacetamide, N‐benzoylpyran, ethylformimidate, pyranopyrimidin‐4‐one, pyranopyridine, pyranopyrimidin‐2‐one, and pyranopyrimidin‐2‐imine derivatives, respectively. Meanwhile, compound 1 was reacted with ethyl bromoacetate, phenacyl bromide, phthalic anhydride, different aromatic amines, and/or acetic acid/H₂SO₄ to produce 5‐aminopyrano[2,3‐b]pyrrole‐6‐carboxylate, dihydropyrano[2,3‐b]pyrrole‐6‐yl‐(phenyl)methanone, 1,3‐dioxoisoindolinyl pyran, 1,4‐dihydropyridine, and 2‐hydroxy‐1,4‐dihydropyridine derivatives, respectively. On the other hand, when compound 1 was allowed to react with maleic anhydride and/or hydrazine hydrate, pyran‐4‐oxobut‐2‐enoic acid and 3‐aminopyranopyrazole derivatives were obtained, respectively. Reaction of pyran‐4‐oxobut‐2‐enoic acid with malononitrile under different conditions gave 2‐(furan‐2‐yl)‐4H‐pyran and 2‐(4H‐pyran‐2‐yl)‐1H‐pyrrole derivatives, while condensation of 3‐aminopyranopyrazole with benzaldehyde gave 1,4‐dihydropyrano[2,3‐c]pyrazol‐3‐yl‐1‐phenylmethanimine derivative. The newly synthesized compounds were characterized by the spectroscopic tools IR, ¹H‐NMR, ¹³C‐NMR, MS, and elemental analysis. Some of these compounds have been screened in vitro for antimicrobial activity against different strains of bacteria and fungi and also were tested against two cancer cell lines: mammary gland breast cancer (MCF‐7) and colon cancer (HCT‐118).     

Synthesis of Pyranopyrazoles under Eco‐friendly Approach by Using Acid Catalysis

Multicomponent synthesis of pyranopyrazole derivatives by using montmorillonite K‐10 as a reusable green acid catalyst under eco‐friendly method in the presence of eco‐friendly solvent leads to novel protocol. Moreover, catalyst could be reused five times for the reaction without noticeable loss of activity. The scope of this path was to develop new synthetic molecules by using green catalysis for further screenings such as starting molecules for organic electronic materials and biological assays.     

Synthesis of Triazoles,Oxadiazoles and Condensed Heterocyclic Compounds Containing Cinchopheny and Studies on Biological Activity of Representative Compounds

Compounds 2‐arylamino‐5‐cinchophenyl‐1,3,4‐oxadiazoline ( 7 ) and 3‐thio‐4‐amino‐5‐cinchophenyl‐1,2,4‐triazole ( 3 ) have been synthesized utilizing cinchophen as the starting material. The compound 3‐cinchopheny‐s‐triazolo[3,4‐b]‐1,2,3,4‐thiatriazole ( 4 ) was prepared from compound 3 . Condensation of 3 with aromatic acid in the presence of POCl₃ gave 10 new 6‐aryl‐3‐cinchopheny‐1,2,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazoles ( 5 ). Some of the representative compounds were screened for antibacterial activity. The structures of these new compounds have been confirmed by means of elemental analysis, IR, ¹H NMR and MS.     

Synthesis and Biological Activity of Tonghaosu Analogs Containing Phenoxy-phenyl Moiety

A new series of phenoxy-phenyl moieties containing tonghaosu analogs with varied B-ring 9 were synthesized and characterized by spectral studies. Their insect antifeedant activity against Pieris brassicae and insecticidal activity against Culex quinquefasciatus were investigated. Compound 9e exhibited excellent antifeeding activity.     

Synthesis and Characterization of Novel Schiff Base Macrocyclic Compounds Containing Thiophene

Several novel Schiff base macrocyclic compounds containing thiophene were synthesized from d/ethyl 3,4-dialkoxythiophene-2,5-dicarboxylate, cyanuric chloride, diethylarnine and p-nitrophenol by reduction, oxidation, substitution and cyclization, and their structures were characterized by IR, NMR and electrospray ionization-rnass spectrorneter（ESI-MS）. The studies on their UV-Vis absorption spectra show that Schiff base rnacrocycles 6-10 have selective recognition for Fe^3＋.     

Synthesis of Pseudo‐Peptides Containing a Quinazolinone Skeleton via Ugi Four‐Component Reaction

A simple and efficient synthesis of quinazolinone pseudo‐peptide derivatives based on a new 3‐amino‐1,2,3,4‐tetrahydro‐4‐oxoquinazoline‐2‐carboxylic acid via Ugi four‐component reaction has been developed. This reaction was conducted under mild conditions with a broad scope of substrates.