Synthesis of 3-(2-(4,5-Dihydro-3,5-diphenylpyrazol-1-yl)thiazol-4-yl)-2H-chromen-2-one Derivatives via Multicomponent Approach

An efficient synthesis of 3-(2-(4,5-dihydro-3,5-diphenylpyrazol-1-yl)thiazol-4-yl)-2H-chromen-2-one derivatives by a simple, atom-economical, and multicomponent reaction of chalcones, thiosemicarbazide, and 3-(2-bromoacetyl) coumarins in the presence of aqueous sodium hydroxide in refluxing ethanol is reported. The structures of newly prepared compounds have been confirmed by their analytical and spectral (IR, ¹HNMR, ¹³CNMR and mass) data.

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One-Pot Synthesis of Novel 2-(Thiazol-2-yl)-4,5-dihydropyridazin-3(2H)-one Derivatives Catalyzed by Activated KSF

A series of 2-(thiazol-2-yl)-4,5-dihydropyridazin-3(2H)-one derivatives were synthesized by one-pot multicomponent cyclocondensation of ketoacid, thiosemicarbazide, and phenacyl bromide using catalytical amount of KSF in EtOH under reflux. The straightforward synthesis, presence of two important class of heterocyclic rings in the individual molecule, easy workup of the products, rapid reaction, mild conditions, and good to excellent yields are notable features of this protocol.

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AgF-Mediated Homocoupling Reaction of Trialkoxy Aryl Silanes

In this article, we present the direct homocoupling reaction of trialkoxy aryl silanes mediated by AgF in moderate to excellent yields in very mild conditions. It is an important complement for the synthesis of symmetrical biaryls by using homocoupling of trialkoxy silanes. In this reaction, no other catalyst such as Pd or Cu was necessary.

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Orthogonally Positioned Diamino Pyrrole- and Imidazole-Containing Polyamides: Synthesis of 1-(3-Substituted-propyl)-4-nitropyrrole-2-carboxylic Acid and 1-(3-Chloropropyl)-4-nitroimidazole-2-carboxylic Acid

Pyrrole- and imidazole-containing polyamides can be tailored to recognize the DNA 6–8 base pair sequence. We found that adding a second amino group via the N1-position of pyrrole or imidazole in polyamides could enhance their DNA binding affinity and water solubility while retaining sequence specificity. Synthesis of the key 1-substituted-4-nitropyrrole (and imidazole)-2-carboxylic acid building blocks are described.

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New Synthetic Route to (1S)-4,5-Dimethoxy-1-[(methylamino)methyl] Benzocyclobutane,a Key Intermediate of Ivabradine

An efficient process for the preparation of (1S)-4,5-dimethoxy-1-[(methylamino)methyl] benzocyclobutane (S)-3 as ivabradine intermediate, which was obtained in 56% yield, is described. The salient feature of this process is the racemization of the undesired (1R)-4,5–dimethoxy-1,2-dihydrocyclobutabenzene-1-carboxylic acid (R)-12, and the overall yield of (S)-12 was improved to 70% by three resolutions of the racemized acid with R-(α)-phenylethanamine. The reduction of amide (S)-13 was achieved with NaBH₄-I₂ in refluxing tetrahydrofuran, giving the corresponding amine (S)-3 in 90% yield. The improved synthetic route described herein is cost-efficient, environmentally friendly and feasibile for scale-up production.

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Highly Diastereoselective Vinylogous Mukaiyama Aldol Reaction of Isatins with 2-(Trimethylsilyloxy)furans Catalyzed by Quinine

The diastereoselective formation of δ-hydroxyalkyl butenolide oxindoles has been achieved via a vinylogous Mukaiyama aldol reaction. The reaction was performed using various (N-alkyl)isatins 1 with 2-(trimethylsilyloxy)furan 2 catalyzed by quinine in tetrahydrofuran (THF). The reaction proceeds rapidly and affords the corresponding 3-hydroxy-(5-oxo-2,5-dihydrofuran-2-yl)indolin-2-ones in good yields with high diastereoselectivities (anti/syn ratio up to 96:4).

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Solvent-Free Microwave-Assisted Preparation of N-(2-(Pyridin-2-yl)-ethyl)sulfonamides

Although nitrogen-containing heterocycles and sulfonamides both play crucial roles in the chemical and pharmaceutical industries, surprisingly little research exists that examines the bifunctional N-(2-(pyridin-2-yl)ethyl)sulfonamide scaffold for any potential applications. Retrosynthetic analysis indicates that this skeleton would be well suited for a conjugate addition reaction. However, the ability of 2-vinylpyridine to behave as an acceptor, and of sulfonamides to behave as donors, has very limited literature precedent, and thus required some preliminary investigations into their mutual reactivity. Herein outlines our laboratory's discovery of a novel and efficient solvent-free 1,4-aza-conjugate addition reaction between sulfonamides and 2-vinylpyridines that provides expedient access to various N-(2-(pyridin-2-yl)ethyl)sulfonamide derivatives. The products, possessing multiple sites of Brønsted acidity and basicity in close proximity, could display a wide array of valuable host–guest properties and should thus be investigated for potent pharmaceutical or agrochemical properties.

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Efficient One-Pot Synthesis of 3-Amino-7-azaindoles Under Microwave Irradiation

An efficient one-pot synthesis of 3-amino-7-azaindoles was developed, starting from ethyl (3-cyanopyridin-2-yl)carbamate and α -bromoketones by microwave-assisted Thorpe–Ziegler cyclization in the presence of a base. This method features excellent yields, short reaction time (10min), and high functional group compatibility.

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C-S Bond-Forming Reactions of Barbiturylbromide with Isothiocarbamides in Aqueous Media

The C-S cross coupling of pharmaceutically active barbituric acid derivatives has been achieved by the interaction of selective monobromobarbituric acid with thioureas in an aqueous medium. This method is applicable for simple thiourea as well as monosubstituted thioureas, and corresponding products are obtained in good yield.

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Vilsmeier Reagent: An Efficient Reagent for the Transformation of 2-Aminobenzamides into Quinazolin-4(3H)-one Derivatives

Clean and easy preparation of quinazolin-4(3H)-one derivatives using 2-aminobenzamides and Vilsmeier reagent is described. 2-Aminobenzamides were converted into the corresponding quinazolinones under mild and efficient conditions, in good yields without undesirable by-products.

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Efficient Room-Temperature Synthesis and Antimicrobial Study of Novel 2-Aroylbenzofuran-3-ols from Substituted Methyl Salicylates and Phenacyl Bromides

The article describes a convenient and efficient synthetic route for the construction of 2-aroylbenzofuran-3-ols from readily available diverse methyl salicylates and phenacyl bromides using K₂CO₃ as catalyst in dimethylformamide as solvent at room temperature. The reaction involves two steps, which occur in quick succession within 1 h to deliver the product with reasonably high yields. All the synthesized 2-aroylbenzofuran-3-ols (4a–u) were subjected for their antimicrobial studies, and some of these have shown prominent activity.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]