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1,4-Diaryl-5-carboxamido substituted 3-trifluoromethylpyrazoles are obtained with exclusive regioselectivity under transition-metal-free conditions. This decarboxylative [3+2] cycloaddition protocol was enabled by employing trifluoromethyl nitrilimines as 1,3-dipoles, and isoxazolidinediones as CO2-masked alkynyl dipolarophiles. The applicability of this method is further manifested by its compatibility with difluoromethyl, alkyl, aryl, and heteroaryl nitrilimines, as well as the preparation of 4-carboxylic amido analogue of drug Celebrex. (Figure presented.).

A novel sequential [3+2] annulation reaction has been developed using prop-2-ynylsulfonium salts and hydrazonyl chlorides, affording a series of pyrazoles with functional motifs that can be post modified in the preparation of various drugs or drug candidates. Further transformation and gram-scale operations could also be achieved efficiently. This journal is

A novel copper-catalyzed [3+2] cycloaddition reaction with concomitant in situ generation of benzoylacrylonitriles and nitrile imines from phenacylmalononitriles and hydrazonoyl chlorides, respectively, is reported. The reaction was performed using copper(I) chloride as catalyst and N-methylimidazole as a clean complexing agent/weak base to afford the functionalized 4-benzoyl-5-cyanopyrazoles in moderate to good yields and excellent regioselectivity under ambient conditions. This method provides rapid access to a wide range of highly functionalized 4-benzoyl-5-cyanopyrazoles.

N-Methylimidazole (NMI) can act as a masked HCN in the synthesis of 1,3-disubstitued-1H-1,2,4-triazoles via a formal cycloaddition reaction of hydrazonoyl chloride with NMI. The product was proved to be formed via an initial nucleophilic substitution of hydrazonoyl chloride with NMI following cyclization and two sequential C-N bond cleavages. This journal is

Various primary alcohols were smoothly transformed into 3-aryl- and 3-alkylisoxazoles in good yields in one pot by successive treatment with PhI(OAc) 2 in the presence of TEMPO, NH 2 OH, and then NCS, followed by reaction with alkynes in the presence of Et 3 N. Similarly, various primary alcohols were smoothly transformed into 3-aryl- and 3-alkylpyrazoles in good yields in one pot by successive treatment with PhI(OAc) 2 in the presence of TEMPO, PhNHNH 2, and then NCS and decyl methyl sulfide, followed by reaction with alkynes in the presence of Et 3 N. Thus, both 3-aryl- and 3-alkylisoxazoles, and 3-aryl- and 3-alkylpyrazoles could be prepared from readily available primary alcohols in one pot under transition-metal-free conditions.

Treatment of N-phenyl-substituted benzenecarbo-hydrazonoyl chlorides 1a-d with malononitrile in sodium ethoxide solution gave 5-amino-4-cyanopyrazole derivatives 2-5. Compounds 2-5 were converted to formidate derivatives 6-9 upon treatment with TEOF in ac

A one-pot approach for the synthesis of epoxypyrrolo[3,4- g ]indazoles is presented. The first step was initiated by a three-component reaction of an isocyanide, a dialkyl acetylenedicarboxylate, and 2-furancarboxylic acid, and led to 1,3-dioxoepoxyisoindole, followed by the addition of hydrazonoyl chloride through a [3+2]-cycloaddition reaction in the second step. The key step in the formation of final compound involves a bicyclization strategy through intramolecular Diels-Alder (IMDA) reaction.

The present disclosure provides compounds, pharmaceutical compositions, and methods for the treatment of cancer and fibrosis. The disclosed pharmaceutical compositions may include one or more pyrazolyl-containing compounds, or a derivative thereof.

A novel synthetic methodology for the preparation of 1,3-disubstituted pyrazoles from in situ generated nitrile imines and acetylene is reported. The reactions are performed in a simple two-chamber reactor. One part of the reactor is loaded with hydrazonoyl chloride precursors of active nitrile imine species and a base. The other part is used to generate acetylene from CaC2 and water. Partitioning of the reactants improves the yields of desired pyrazoles up to 99% and simplifies their isolation to a simple procedure of solvent evaporation. The approach requires no complex equipment and utilizes inexpensive, safe, and easy to handle calcium carbide as a starting material. A model deuterium incorporation is carried out according to the developed methodology, producing a series of novel 4,5-dideuteropyrazoles with excellent deuterium enrichment. Theoretical calculations on reaction mechanism and characterization of possible intermediate structures were performed.

The design and synthesis of a library of twenty-six spirotriazoline oxindoles and their in vitro evaluation as potential anticancer agents is reported. The antiproliferative activity of the synthesized compounds was assessed against four different cancer cell lines (HCT-116 p53 (+/+), HCT-116 p53 (?/?), MCF-7, and MDA-MB-231). Four spirotriazoline oxindoles showed selectivity against the four cancer cell lines tested over the non-cancer derived HEK 293T cell line. To characterize the molecular mechanisms involved in compound antitumoral activity, two spirotriazoline oxindoles were selected for further studies. Both compounds were able to induce apoptosis and cell cycle arrest at G0/G1 phase and upregulated p53 steady-state levels, while decreasing its main inhibitor MDM2, in HCT-116 cells. Importantly, cytotoxic effects induced by spirotriazoline oxindoles occurred in cancer cells without eliciting cell death in non-malignant CCD-18Co human colon fibroblasts. In addition, four spirotriazoline oxindoles showed selectivity against the triple-negative breast cancer cell line MDA-MB-231 with IC50 values of 3.5–6.7 μM. These results highlight the anticancer potential of spirotriazoline oxindoles, especially when dealing with aggressive and challenging triple-negative breast cancer.

The double 1,3-dipolar cycloaddition of allenoates with nitrilimines has been achieved under mild reaction conditions, affording a variety of spirobidihydropyrazoles in moderate to excellent yields with excellent diastereoselectivities. The reaction diastereoselectively constructs double dihydropyrazole moieties and two chiral centers including a spiro carbon center.

A series of spiro[indoline-3,2′-[1,3,4]oxadiazol]-2-ones were prepared from the reaction of isatin derivatives and hydrazonoyl chlorides through the 1,3-dipolar cycloaddition reaction. This method has some important aspects, such as mild reaction condition, easy purification, and high yield of products. Also, the synthesis of spiro[acenaphthylene-1,2′-[1,3,4]oxadiazol]-2-one and spiro[[1,3,4]oxadiazole-2,9′-phenanthren]-10′-one were studied under the same condition. The structures were confirmed spectroscopically (IR,1H- and13C-NMR, and EI-MS) and by elemental analyses. A plausible mechanism for this reaction is proposed.

In this paper 1,3-dipolar cycloaddition reaction has been studied. An efficient synthesis of 4′-[3-methyl-5-thioxo-1H-1,2,4-triazol-4(5H)-yl]- 2′,5′-diphenyl-2′,4′-dihydro spiro(indolin-3,3′[1, 2,4]triazol)-2-one derivatives using triethylamine in MeCN at room temperature is reported. The structures of the obtained compounds were confirmed by means of elemental analysis, MS and spectral (IR, 1H, and 13C NMR) methods.

A new 1,3-dipolar cycloaddition of nitrile imines with 3-alkenyl-oxindoles was catalyzed by a new chiral Mg(ClO4)2 complex of an N,N'-dioxide ligand. The reaction is so far the sole catalytic synthesis of spiro-pyrazoline-oxindole derivatives. A wide variety of substrates were explored to obtain good yields (up to 98%) and excellent enantioselectivities (up to 99%). This cycloaddition expands the scope of propargyl anion type 1,3-dipole in the construction of 2-pyrazoline subunit.

Eleven novel dihydropyrrolo[3,4-c]pyrazole derivatives were obtained by the reaction of chiral (1R)-N-(1-phenylethyl)maleimide and C,N-aryl-substituted nitril-imines. The reaction afforded the cycloadducts as a regioisomeric mixture which can be separable in some cases. The structure and stereochemistry of cycloadducts were assigned on the basis of infrared (IR), 1H and 13C nuclear magnetic resonance (NMR), mass and X-ray spectra, optical rotation measurements, and CHN analyses.

We present a two-step procedure for the synthesis of 1,2,4-triazole derivatives from a primary amide and a hydrazine via an oxidative process. Georg Thieme Verlag Stuttgart.

Twenty-nine novel bis(dihydropyrrolo[3,4-c]pyrazole) derivatives were obtained by reacting C, N-phenyl-substituted nitrilimines generated in situ from corresponding hydrazonyl chlorides with bismaleimides. The structures were elucidated by physical and spectroscopic methods [m.p., Rf, infrared (IR),1H nuclear magnetic resonance (NMR), 13C NMR, correlation spectroscopy (COSY), heteronuclear correlation (HETCOR), nuclear Overhauser effect (NOE), and high-resolution mass spectrometry (HRMS)]. Also, Hammett correlation graphs were obtained between Hammett constants σp and λmax values of bis(pyrrolopyrazoles) carrying p-substituted phenyl-ring-bearing electron-withdrawing and electrondonating groups and discussed in terms of substituent effects. Springer-Verlag 2010.

A series of cycloadducts - pyrazoles via 1,3-dipolar cycloaddition reactions of generated nitrilimines with N-(4-chloro-2-fluorophenyl)maleimide were described. The novel compounds synthesized were characterized by 1H NMR, MS, and elemental analysis. The fungicidal tests showed that most of the title compounds exhibit significant fungicidal activities against Corynespora cassiicola.

Novel 1,3-diarylcycloalkanopyrazoles 1, and diphenyl hydrazides 2 were identified as selective inhibitors of cyclooxygenase-2. The 1,3-diaryl substitution pattern of the pyrazole ring in 1 differentiates these compounds from most of the known selective COX-2 inhibitors that contain two aryl rings at the adjacent positions on a heterocyclic or a phenyl ring. Similarly, the two phenyl rings in 2 are also separated by three atoms. SAR of both phenyl rings in 1 and 2, and the aliphatic ring in 1 will be discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.