The photochemical synthesis of 6-acyl-5H-benzo[a]phenoxazin-5-ones

6-Acyl-5H-benzo[a]phenoxazin-5-ones were prepared by the photochemical reaction of 5H-benzo[a]phenoxazin-5-one with aldehydes.

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Die photochemische Synthese von 6-Acyl-5H-benzo[a]phenoxazin-5-one (Kurze Mitteilung)

Zusammenfassung Die Titelverbindungen wurden mittels photochemischer Reaktion von 5H-Benzo[a]phenoxazin-5-onen mit Aldehyden hergestellt.

     

Simple synthesis of 6-alkyl-5H-benzo[a]phenoxazin-5-ones

6-Alkyl-5H-benzo[a]phenoxazin-5-ones were prepared by the reaction of 5H-benzo[a]phenoxazin-5-one with carboxylic acid in the presence of silver ion and peroxydisulfate.

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Eine einfache Synthese von 6-Alkyl-5H-benzo[a]phenoxazin-5-onen (Kurze Mitteilung)

Zusammenfassung 6-Alkyl-5H-benzo[a]phenoxazin-5-one wurden mittels Reaktion von 5H-Benzo[a]phenoxazin-5-onen mit Carbonsäuren in Gegenwart von Silberionen und Peroxydisulfat dargestellt.

     

Synthesis of some 5H-benzo[a]phenothiazin-5-one derivatives

Several substituted 6-anilino-5H-benzo[a]phenothiazin-5-one derivatives were prepared by condensation of substituted 1,4-naphthoquinones with 2-aminobenzenethiol in pyridine. The reduction and acetylation of the resulting compounds were also investigated.

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Synthese einiger 5H-Benzo[a]phenothiazin-5-on-Derivate

Zusammenfassung Es wurden mittels Kondensation substituierter 1,4-Naphthochinone mit 2-Aminothiophenol in Pyridin einige substituierte 6-Anilino-5H-benzo[a]phenothiazin-5-one dargestellt. Die Reduktion und Acetylierung der resultierenden Verbindungen wurde ebenfalls untersucht.

     

A NOVEL SYNTHESIS OF 2-SUBSTITUTED-4H-THIENO [2,3-d][1,3] OXAZIN-4-ONE AND 2,3-DISUBSTITUTED THIENO [2,3-d]PYRIMIDIN-4(3H)-ONE DERIVATIVES

Abstract

The synthesis of acetic 2-{[1-methyl-2-(4-oxo-5,6,7,8-tetrahydro-4H-benzo [4,5]-thieno [2,3-d] [1,3-oxazin-2-yl)ethylidene]amino}-4,5,6,7-tetrahydrohenzo[b]thiophene ?3-carboxylic acid anhydride 5 and 2-(oxopropyl)-5,6,7,8-tetrahydro-4H-benzo-[4,5] thieno[2,3-d][1,3]oxazin-4-one 7, has been achieved in three steps from ethyl 2-amino-4,5,6,7-tetrahydrobenzo(b]thiophene-3-carboxlate 1 via the reaction with ethyl acetoacetate followed by hydrolysis and acetic anhydride-induced cyclization. The 2-substituent in compound 5 has two functional groups i.e. active methylene and acid anhydride which are suitably located for intramolecular transformation. Thermal and/or base catalyzed intramolecular cyclization of 5 afforded 2-(4-acetoxy-(hydroxyl)-2-methyl-5,6,7,8-tetrahydrobenzo[4,5] thieno[2,3-b]pyridin-3-yl)-5,6,7,8- tetrahydro-4H-benzo[4,5]thieno[2,3-d] [1,3]oxazin-4-one 10 and 9 respectively. Treatment of 5 with hydrazine hydrate, aromatic and/or heterocyclic amines induced the same intramolecular cyclization with a concomitant oxazine-pyrimidine interconversion to give 3-amino(aryl or heteryl)-2-(4-hydroxy-5,6,7,8-tetrdhydrobenzo-[4,5]thieno[2,3-b]pyridin-3-yl)-3,4,5,6,7,8-hexahydrobenzo[4,5] thieno[2,3-d] pyrimid in-4-one 11–14 respectively.     

The dehalogenation of the halo substituted 5H-benzo[a]phenothiazin-5-ones and 3H-phenothiazin-3-ones

6-Bromo- and 6-chloro-5H-benzo[a]phenothiazin-5-ones were dehalinated to 5H-benzo[a]phenothiazin-5-one in the presence of sodium hydrosulfite (disodiumdithionite · 2H₂O) dissolved in aqueous pyridine under nitrogen atmosphere.

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Enthalogenierung von halogensubstituierten 5H-Benzo[a]phenothiazin-5-onen und 3H-Phenothiazin-3-onen

Zusammenfassung 6-Brom- und 6-Chlor-5H-benzo[a]phenothiazin-5-on lassen sich in wäßrigem Pyridin in Gegenwart von Natriumdithionit unter Stickstoff zu 5H-Benzo[a]phenothiazin-3-on enthalogenieren.

     

Synthesis and anticancer activity evaluation of 3-(4-oxo-2-thioxothiazolidin-5-yl)-1H-indole-carboxylic acids derivatives

Abstract

A mild and efficient method for the synthesis of 1-oxo-9H-thiopyrano[3,4-b]indole-3-carboxylic acids and dimerized 3-(4-carboxy-1H-3-indolyl)-2-propenoic acids via alkaline hydrolysis of 3-(rhodanin-5-yl)-1H-indole-2-carboxylic acids derivatives was elaborated. Anticancer activity screening in NCI60-cell lines assay allowed identification of 5-fluoro-3-(4-oxo-2-thioxothiazolidin-5-ylidenemethyl)-1H-indole-2-carboxylic acid methyl ester 2a with significant antimitotic activity at micromolar and submicromolar concentrations.     

离子液体中6-(2,3-环氧丙氧基)-2(1H)-喹啉酮及其衍生物的合成

6-(3-氨基-2-羟基丙基)-2-(1H)-喹啉酮衍生物被发现具有新的正性肌力的活性. 设计合成了一系列新的氨丙醇类喹啉酮化合物. 首先研究了6-羟基-2-(1H)-喹啉酮环氧化物2在离子液体中的合成, 该反应后处理简便, 收率高, 对环境友好. 然后用合成得到的2-(1H)-喹啉酮环氧化合物在离子液体中与一系列具有生物活性的有机碱反应, 合成了氨丙醇类2-(1H)-喹啉酮化合物3. 然后由6-羟基-2-(1H)-喹啉酮出发, 在离子液体中, 进行了一锅法合成氨丙醇类2-(1H)-喹啉酮化合物的研究. 制得的2b, 3b～3f 6个新化合物用IR, ¹H NMR, MS和元素分析进行了结构表征.     

A one-pot synthesis of 8-amino-1-methoxy-6<Emphasis Type="Italic">H</Emphasis>-dibenzo[<Emphasis Type="Italic">b,d</Emphasis>]pyran-6-one

8-Amino-1-methoxy-6H-dibenzo[b,d]pyran-6-one was synthesized in a one-pot reaction of 2′,6′-dimethoxy-4-nitro-1,1′-biphenyl-2-carboxylic acid methyl ester using hydroiodic acid as a reagent to effect O-demethylation, lactonization, and nitro reduction to amine. This new reaction represents an improved alternative to the previously reported three-step reactions for this transformation.     

Synthesis,Characterization, and Antimicrobial Evaluation of Some Novel 4-Hydroxyquinolin-2(1H)-ones

Vilsmeier–Haack formylation of 3-acetyl-1-methyl-4-hydroxyquinolin-2(1H)-one (2) produced the novel 6-methyl-4,5-dioxo-5,6-dihydro-4H-pyrano[3,2-c]quinoline-3-carboxaldehyde (3). Reactions of carboxaldehyde 3 with a diversity of nucleophilic reagents were studied and a variety of products were obtained via ring-opening, ring-closing (RORC) sequence. Also, some novel heteroannulated pyrano[3,2-c]quinolines were prepared. Structures of the new synthesized products were deduced on the basis of their analytical and spectral data.     

Synthesis of some novel 5-substituted benzamido-6-arylamino-pyrazolo[3,4-D]pyrimidin-4-one derivatives for herbicidal activity

Abstract

Sixteen novel 3-methylthio-5-substituted benzamido-6-arylamino-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4 (5H)-one derivatives (4a–p) were successfully synthesized from iminophosphoranes, aryl isocyanate, and substituted benzoylhydrazine. The structures of the title compounds were elucidated by FT-IR, ¹H NMR, ¹³C NMR, and HRMS. Herbicidal activity of the compounds 4a–p against Brassica napus (rape), Echinochloa crusgalli (barnyard grass), Cucumis sativus (cucumber), and Triticum aestivum (wheat) were determined. The results showed that 5-(2-chlorobenzamido)-6-phenylamino-3-methylthio-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4 (5H)-one (4c) displayed remarkable inhibition activity against the stalk and root of rape with 100% inhibition rate at the dosages of 10?mg/L and 100?mg/L, and 5-(4-nitrobenzamido)-6-phenylamino-3-methylthio-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4 (5H) -one (4d) exhibited excellent activity against the stalk and root of barnyard grass with 100% inhibition rate at the same dosages.     

Facile synthesis and characterization of novel pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidin-4(3H)-one and pyrido[2′,3′:3,4]pyrazolo[1,5-a]pyrimidine incorporating 1,3-diarylpyrazole moiety

4-(3-(4-Hydroxyphenyl)-1-phenyl-1H-pyrazol-4-yl)-6-phenyl-2-thioxo-1,2-di hydro-pyridine-3-carbonitrile (1) reacted with ethyl chloroacetate (2) in ethanolic sodium acetate solution to yield the corresponding ethyl (3-cyanopyridin-2-ylsulphanyl)acetate derivative 3. Intramolecular cyclization of compound 3 was achieved by its heating in DMF containing potassium carbonate to afford the corresponding ethyl 3-aminothieno[2,3-b]pyridine-2-carboxylate derivative 4 which reacted with hydrazine hydrate in refluxing pyridine to yield the starting material 3-aminothieno[2,3-b]pyridine-2-carbohydrazide derivative 7. Compound 7 reacted with different reagents such as triethylorthoformate, formic acid, acetic acid and acetic anhydride to afford the target molecules pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidin-4(3H)-one derivatives 8–10, 12 and 13 in good to excellent yields. On the other hand, pyridine-2(1H)-thione derivative 1 reacted with hydrazine hydrate in refluxing pyridine to give the other starting material 3-amino-1H-pyrazolo[3,4-b]pyridine derivative 20 which reacted with acetylacetone under reflux to afford the target molecule pyrido[2′,3′:3,4]pyrazolo[1,5-a]-pyrimidine derivative 21 in a good yield. The structures of target molecules were elucidated using elemental analyses and spectral data.     

Synthesis,Reactions, and Antiviral Activity of 1-(1H-Pyrazolo[3,4-b]pyridin-5-yl)ethanone and Pyrido[2′,3′:3,4]pyrazolo[5,1-c][1,2,4]triazine Derivatives

1-(3-Amino-6-methyl-4-pyridin-3-yl-1H-pyrazolo[3,4-b]pyridin-5-yl)ethanone (3) was obtained in very pure state and used as a good starting material for the present study. It diazotized to give the corresponding diazonium salt 9 and also reacted with phenyl isothiocyanate to give the corresponding thiourea derivative 4. Compound 4 was used for the preparation of thiazole derivatives 5–8 via the reaction with active halogen-containing compounds. On the other hand, compound 9 coupled with several active –CH₂- containing compounds to afford the corresponding triazine derivatives 10–17. Considering the data from IR, ¹ H NMR, mass spectra, and elemental analyses, the chemical structures of the newly synthesized heterocyclic compounds were elucidated. Cytotoxicity, anti-HSV1, and anti-HAV-MBB activity were evaluated for the newly synthesized heterocyclic compounds.     

Palladium-catalyzed dual C–H activation of N-phenyl-1H-indole-3-carboxamides for the synthesis of 5,11-dihydro-6H-indolo[3,2-c]quinolin-6-ones

In this paper, we report a palladium-catalyzed dual C–H activation of N-phenyl-1H-indole-3-carboxamides for the synthesis of 5,11-dihydro-6H-indolo[3,2-c]quinolin-6-ones. The optimal reaction conditions were to use 20 mol % of Pd(TFA)₂ as the catalyst, 2.0 equivalents of Cu(OAc)₂ as the oxidant, 1.0 equivalent of K₃PO₄ as the base, and 3.0 equivalents of PivOH as the additive in DMF/dioxane (1: 9). When carried out at 120 °C for 24 h, the reaction could provide nineteen target indoloquinolinones in modest to excellent yields, including the N,N′-dimethylated and N,N′-unsubstituted products which are inaccessible by the reported C–H activation methodologies. The dual C–H activation reaction was also applicable to N-phenyl-1H-indole-2-carboxamides and formed the corresponding 5,7-dihydro-6H-indolo[2,3-c]quinolin-6-ones. A plausible reaction mechanism based on the data from the control experiments and the literatures was proposed to account for the transformation.     

VERSATILE SYNTHESIS AND FUNGICIDAL ACTIVITIES OF 6-AMINO-3- ALKYLTHIO-1,5-DIHYDRO-1-PHENYL-PYRAZOLO [3,4-D]PYRIMIDIN-4-ONE DERIVATIVES

A series of new 6-alkylamino-3-alkylthio-1-phenyl-1H-pyrazolo[3,4-d] pyrimidin-4(5H)-one derivatives 5 and 6 have been rapidly synthesized by a novel solution-phase regioselective synthetic method. Treatment of pyrazole o-aminoester 1 with dibromotriphenylphosphorane gave iminophosphorane 2, which underwent a aza-Wittig reaction with phenyl ioscyanate to provide the carbodiimide 3. The latter intermediate reacted with alkylamines and regioselectively provided the 1,5-dihydro-pyrazolo[3,4-d]pyrimidin-4-one derivatives 5 and 6, some of which exhibited good fungicidal activity.     

Synthesis and Characterization of New Chalcone Derivatives from cis-Bicyclo[3.2.0]hept-2-en-6-one

A series of chalcone derivatives (3a–k) were prepared via the reaction of cis-bicyclo[3.2.0]hept-2-en-6-one (1) with the respective arylaldehydes (2a–k) and were then characterized by Fourier transform infrared (FT-IR), ¹H NMR, ¹³C NMR, and elemental analyses.     

A simple and efficient approach for the synthesis of a novel class aliphatic 1,3,4-thiadiazol-2(3H)-one derivatives via intramolecular nucleophilic substitution reaction

In this study, we synthesized a new series of substituted aliphatic 1,3,4-thiadiazol-2(3H)-one derivatives (6-24) in yields ranging from 42 to 70% with an interesting mechanism that involves internal nucleophilic substitution followed by an S_N2-type nucleophilic substitution. First, 1-(4-chlorophenyl)-2-((5-methyl-1,3,4-thiadiazol-2-yl)thio)ethanone (3) was synthesized from the reaction of 5-methyl-1,3,4-thiadiazole-2-thiol (1) with 2-bromo-1-(4-chlorophenyl)ethanone (2) in the presence of potassium hydroxide. Then, 1-(4-chlorophenyl)-2-((5-methyl-1,3,4-thiadiazol-2-yl)thio)ethanol (4) was synthesized by a reduction reaction of this compound using NaBH₄. Finally, 5-methyl-3-alkyl-1,3,4-thiadiazol-2(3H)-one derivatives (6-24), which are the target compounds, were synthesized from the reaction of this compound (4), which is a secondary alcohol with various alkyl halides (5a-n) in the presence of sodium hydride (NaH). This study presents an interesting reaction mechanism related to the synthesis of aliphatic 1,3,4-thiadiazol-2(3H)-one derivatives that is not recorded in the literature.     

An efficient one-pot expeditious synthesis of 3-phenyl-1-(6-phenyl-7H-[1,2,4] triazolo[3,4-b] [1,3,4] thiadiazin-3-yl)-1H-pyrazol-5-amines via multicomponent approach

An efficient synthesis of 3-phenyl-1-(6-phenyl-7H-[1,2,4] triazolo[3,4-b][1,3,4]thiadiazin-3-yl)-1H-pyrazol-5-amines was accomplished by a simple, atom-economical, and multicomponent approach. Reaction of 4-amino-5-hydrazinyl-4H-1,2,4-triazole-3-thiol with various phenacyl bromides and benzoylacetonitriles in ethanol and catalytic amount of acetic acid afforded the titled compounds. The structures of newly synthesized compounds were confirmed by their analytical and spectral (IR, ¹H-NMR, ¹³C-NMR, and Mass) data.     

Condensed Isoquinolines. 17. Enamine Properties of Benzimidazo[1,2-b]isoquinolin-11(5H)-one in Alkylation Reactions

The alkylation of benzimidazo[1,2-b]isoquinolin-11(5H)-one has been studied. This occurs at N₍₅₎ or C₍₆₎ depending on the type of alkylating agent and the reaction conditions. It was shown that C₍₆₎ alkylation is effected in reactions with reactive alkyl halides. A repeat alkylation occurs preferentially at the same position. Interaction with o-xylylidene dibromide leads to spiro[benzimidazo[1,2-b]-isoquinolin-6,2'-indan]-11-one and 1,6-dihydro-11H-6a,11b-diazobenzo[b]benzo[5,6]cyclohepta[1,2,3-l,m]fluoren-11-one, which are derivatives of new heterocyclic systems.     

Activated nitriles in heterocyclic synthesis: Synthesis of 6-thiophen-2-yl and 6-furan-2-ylthiazolo[2,3—a]pyridine derivatives

A variety of new 6-thiophen-2-yl and 6-furan-2-ylthiazolo[2,3—a]pyridine derivatives could be prepared via the reaction of 2-functionally substituted methyl-2-thiazolin-4-one with cyanomethylenethiophen-2-yl and cyanomethylenefuran-2-yl derivatives. The structure of the reaction products was established based on spectral data.

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Aktivierte Nitrile in der Heterocyclen-Synthese: Die Synthese von 6-Thiophen-2-yl-und 6-Furan-2-yl-thiazolo[2,3—a]pyridin-Derivaten

Zusammenfassung Es konnte eine Reihe neuer 6-Thiophen-2-yl- und 6-Furan-2-yl-thiazolo-[2,3—a]pyridine über die Reaktion von 2-funktionell-substituierten Methyl-2-thiazolin-4-onen mit Cyanomethylenthiphen-2-yl bzw. Cyanomethylenfuran-2-yl-Derivaten hergestellt werden. Die Struktur der Reaktionsprodukte wurde mit spektroskopischen Methoden ermittelt.

     

Synthesis and antiemetic activity of 1,2,3,9-tetrahydro-9-methyl-3-(4-substituted-piperazin-1-ylmethyl)-4H-carbazol-4-one derivatives

5-HT₃ receptor antagonists, such as Ondansetron, are used for anti-emesis after chemotherapy, radiotherapy and operations. Some Ondansetron analogs possessing piperazine ring as side chains were synthesized in our lab. Thus, one of the two carbonyl groups of starting material 1,3-cyclohexandione (1) was condensed with phenylhydrazine hydrochloride to form monophenylhydrazone (2). 1,2,3,9-Tetrahydro-4H-carbazol-4-one (3) was prepared from 2 via cyclization and rearranged in the presence of ZnCl₂. Through a methylation reaction, compound 3 was converted to 1,2,3,9-tetrahydro-9-methyl-4H-carbazol-4-one (4). 3-Dimethylaminomethyl substituted compound (5) was synthesized from 4 by a Mannich reaction in glacial acetic acid. Nine novel 1,2,3,9-tetrahydro-9-methyl-3-(4-substituted-piperazin-1-ylmethyl)-4H-carbazol-4-one derivatives (6a–6i) were synthesized through nucleophilic substitution reaction of 5 with piperazines. The structures of all the target compounds were determined by elemental analysis, IR, MS, ¹H NMR and ¹³C NMR spectra. The results of preliminary pharmacological test show that part of the novel compounds have antiemetic activity comparable to that of the control Ondansetron. __________ Translated from Chinese Journal of Organic Chemistry, 2008, 28(2) (in Chinese)