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A convenient synthesis of a broad series of thirteen examples of alkyne-spacer derivatives 2 from the well-known Sonogashira cross-coupling reaction on diazenyl-pyrazolo[1,5-a]pyrimidin-2-amine compounds 1 is reported. The reactivity of heterocycles 1 due the presence of selected electron-donor (EDG) and electron-withdrawing (EWG) groups attached to different alkynes was evaluated. Also, the reactional versatility due the position variation of the bromo atom at the scaffolds 1 was also investigated. In general, derivatives presented strong absorption bands at the 250-500 nm optical window and UV to cyan emission properties. Also, the redox analysis was recorded by electrochemical cyclic voltammetry technique. For HSA biomacromolecule assays, spectroscopic studies by UV-Vis, steady-state and time-resolved emission fluorescence, and molecular docking calculations evidenced the ability of each compound to establish interactions with human serum albumin (HSA). Finally, the behavior presented for this new class of heterocycles makes them a promising tool as optical sensors for albumins.

The present work reports the biological assays between synthetic BF2-naphtyridine complexes and four proteins: human serum albumin (HSA), calf-thymus DNA (CT-DNA), tyrosinase and acetylcholinesterase enzymes via spectroscopic analysis at physiological conditions, combined with molecular docking simulations. The BF2-complexes presented spontaneous and moderate binding ability to HSA through the ground-state association (static fluorescence quenching mechanism). The main binding site is Sudlow's site I (subdomain IIA) and the binding does not perturb significantly both secondary and surface structure of HSA. Despite BF2-complexes showed good binding ability with HSA, these compounds presented weak intercalative ability with CT-DNA (the most conventional and simple model to preliminary studies), except in the case of 1 h, which suggested that the presence of electronic donor groups in both aromatic ring moieties of BF2-complex structure can increase the intercalative ability for DNA strands. Competitive binding displacement assays in the presence of methyl green and molecular docking calculations indicated that the studied compounds interact preferentially in the major groove of DNA. In addition, the assayed compounds presented the ability to activate or inhibit both tyrosinase (the decontrolled activity can induce melanoma carcinoma) or AChE (involved in reactions related to the function of neurotransmitters) enzymes.

This paper describes the synthesis of a novel series of 2-aryl-6-(1H-indol-1-yl)-4-(trifluoromethyl)quinolines, in which aryl = C6H5, 4-CH3C6H4, 4-FC6H4, 4-CF3C6H4 and heteroaryl = 2-thienyl, by an Ullmann-type cooper-catalyzed amination cross-coupling reaction. Photophysical properties of indolyl-quinolines were investigated using absorption and emission analysis. The emission fluorescence analysis showed a blue to cyan region emission in the 400–650 nm range. Large Stokes shifts values were observed for all new quinolines and attributed to the ICT state and to the electron-substituent properties. The ability to generate 1O2 species after being exposed to white light and biomolecule-binding DNA / HSA properties were also investigated.

An efficient protocol for the assembly of a new series of 1,3-disubstituted 4,5-bis(trifluoromethyl)-1H-pyrazoles – through a concise sequential iodination-trifluoromethylation reaction at the C-4 position of an initial series of 1-aryl-3-(alkyl/aryl)-5-trifluoromethyl-1H-pyrazoles (electronically deactivated heterocycles), using NIS and MFSDA, at good conversion yields and in short reaction times – is reported.

Reaction of 5-bromo enones with pyrazoles provided a series of unexpected N,O-aminal derivatives, through a 1,4-conjugated addition at the β-carbon of the 5-bromo enones instead of the expected nucleophilic substitution of the bromine. This reaction also furnished the 1,3-regioisomer of the pyrazole. A similar reaction of pyrazoles using 5-bromo enaminones furnished only N-alkylated pyrazoles-with high regioselectivity and at good yields-through nucleophilic substitution of the bromine.

Glioblastoma is the most common and aggressive glioma, characterized by brain invasion capability. Being very resistant to the current therapies, since even under treatment, surgery, and chemotherapy with temozolomide (TMZ), patients achieve a median survival of one year. In the search for more effective therapies, new molecules have been designed. For nervous system cancers, molecules able to cross the blood-brain barrier are handled with priority. Accordingly, tacrine was chosen for this study and the inclusion of spiro-heterocyclic rings was done in its structure resulting in new compounds. Cytotoxic activity of tacrine derivatives was assayed using glioblastoma cell line (SF295) as well as analyzing cell death mechanism. Increased caspases activities were observed, confirming apoptosis as cell death type. Some derivatives also increased reactive oxygen species formation and decreased the mitochondrial membrane potential. Moreover, compounds acted on several glioblastoma-related proteins including p53, HLA-DR, beta-catenin, Iba-1, MAP2c, Olig-2, and IDH1. Therefore, tacrine derivatives presented promising results for the development of new glioblastoma therapy, particularly to treat those patients resistant to TMZ.

The present paper describes first an efficient methodology for an easy O -functionalization (alkylation) of tetracyclic hydroxyisoxazolines 1 applied to the synthesis of eight examples of new 3-(alkoxy)-3-(trifluoromethyl)-3,3a-dihydrospiro[chromeno [4,3- c ]isoxazole-4,1′-cycloalkanes] ( 6-9 ) at 61–84% yields, in which the alkoxy substituents were methoxy, benzyloxy, allyloxy, or prop-2-yn-1-yloxy; while the cycloalkanes were 5-, 6-, and 7-membered carbocycles, as well as 4′-methyl- and 4′- t -butyl-cyclohexane. The reaction medium used 1 , four alkyl halides ( 2 - 5 ), K 2 CO 3 , and KI in DMF at room temperature. The selected 3-(prop-2-yn-1-yloxy)-substituted isoxazolines 6 were successfully used as a CC -fragment in the construction of another series of five examples of 3-((1-benzyl-1 H -1,2,3-triazol-4-yl)methoxy)-3-(trifluoromethyl)-3,3a-dihydrospiro[chromeno[4,3- c ]isoxazole-4,1′-cycloalkanes] ( 10 ), at 36–84% yields, through a regioselective 1,3 dipolar cycloaddition reaction catalyzed by copper iodide (CuAAC), using benzyl azide as an NNN -building block (Click Chemistry).

This study reports a comparison between conventional methods, ionic liquids, microwave (MW) irradiation, and combinations thereof for the synthesis of a series of fourteen 1-aryl-2-arylamino-5-trifluoroacetyl-1,2,3,4-tetrahydropyridines. In all of the reactions tested, the products were obtained at very good yields (87–97%), but the reaction times were very different, depending on the method used. Comparing to other methods, the time decreased to 1 min when [BMIM]BF 4 under MW irradiation was used, thus evidencing a synergic effect.

This paper firstly describes the synthesis of a series of (Z)-4-((3-chloro-4-fluorophenyl)amino)-1,1,1-trifluorobut-3-en-2-ones (3a–f) as well as 1-(1-((3-chloro-4-fluorophenyl)amino)-3,4-dihydronaphthalen-2-yl)-2,2,2-trifluoroethanone (3g), from the O,N-exchange reaction of some 4-methoxy-4-alkyl(aryl)-1,1,1-trifluoroalk-3-en-2-ones (1) with 3-chloro-4-fluoroaniline (2), at 70–90% yields. Subsequently, in concentrated sulfuric acid, the enaminoketones 3 underwent a successful and regioselective intramolecular cyclocondensation reaction, which furnished a novel series of 2-alkyl(aryl)-7-chloro-6-fluoro-4-(trifluoromethyl)-quinolines (4) at 70–85% yields. To demonstrate synthetic applicability through the Sonogashira coupling reaction for obtaining quinolines with potential antimicrobial activity, the synthesis of a novel series of 2-alkyl(aryl)-6-fluoro-7-(phenylethynyl)-4-(trifluoromethyl)-quinolines (5) was performed, using quinolines 4 and phenylacetylene, via a regioselective Sonogashira coupling reaction (25–50% yield). Unfortunately, the new series of heterocycles 4 and 5 did not produce significant results against bacteria and fungi at the concentrations of 80–0.31 μg/mL.

This paper reports the results of the synthesis and structural elucidation by multinuclear NMR spectroscopy and single crystal X-ray diffraction of a new series of four examples of 1,1-difluoro-3-methyl-9-(aryl/heteroaryl)-7-(trifluoromethyl)-1H-[1,3,5,2]oxadiazaborinino[3,4-a][1,8]naphthyridin-11-ium-1-uides, which were obtained, at good yields (60–66%), from the reaction of 7-substituted N-(5-(trifluoromethyl)-1,8-naphthyridin-2-yl)acetamides — in which the 7-substituents are C6H5, 4-CH3C6H4, 4-FC6H4, and 2-Thienyl — with BF3·Et2O solution. One-dimensional multinuclear NMR spectroscopy (1H, 13C, 19F, and 11B) and two-dimensional 1H–15N HMBC are presented as powerful tools for an easy and secure NMR chemical shift assignments and structural characterization of fluorinated 1,8-naphthyridine-based boron complexes. Additionally, investigations of photophysical, electrochemical and DNA-binding properties were done.

A series of seven novel scaffolds of 2-substituted 4-trifluoromehyl-5H-chromeno[4,3-b]pyridin-5-ones (3a-g), where R (2-substituents) = Me, Ph, 4-tolyl, 4-NO2C6H4, 4-FC6H4, 4-BrC6H4, and 2-thienyl, were easily and regioselectively synthesized by employing a [3 + 3] cyclocondensation reaction of 4-methyl(aryl/thienyl)-4‑methoxy-1,1,1-trifluoroalk-3-en-2-ones (1) with 4-aminocoumarin (2) in up to 66% yields. The photophysical and electrochemical analysis of 3a-g revealed large Stokes shifts (30 to 130 nm) due to the ICT state and low redox oxidation processes. Additionally, the antioxidant activity evaluated by DPPH assays (aided by cyclic voltammetry) showed that compounds 3b (R = Ph, EC50 (µM) = 19.6) and 3e (R = 4-FC6H4, EC50 (µM) = 19.1) had the most significant radical scavenging capacity (ref. ascorbic acid = 10.9 µM).

A new, simple, and efficient method for the synthesis a novel series of 1-substituted 4-(trifluoromethyl)-5-(alkan-1-ol)-pyridin-2(1 H )-imines from the reaction of 3-(5,6-dihydro-4 H -pyran-3-yl)-4,4,4-trifluorobut-2-enenitrile and 3-(4,5-dihydrofuran-3-yl)-4,4,4-trifluorobut-2-enenitrile with primary amines – is described. The products were obtained in 29–82% yield.

This work reports the synthesis of a series of (1H-1,2,3-triazol-4-yl)carbohydrazides (2), which were obtained from 4-trichloroacetyl-1H-1,2,3-triazoles (1). Triazoles 1 were synthesized by 1,3-dipolar cycloaddition reaction, starting from 4-alkoxy-1,1,1-trichloroalk-3-en-2-ones and benzyl azides and easily (15 min) converted to 2 by reaction with hydrazine hydrate (73–82% yield). Carbohydrazides 2 proved to be a versatile building block for constructing a series of fluorinated heterocycles analogous to rufinamide, i.e., 1H-1,2,3-triazol-4-yl-1,3,4-oxadiazoles, a pyrrole derivative, and a 2-pyrazoline, through [4+1]–, [1+4]–, and [3+2]–cyclocondensation reactions, respectively. Finally, and according to the Lipinski’s rule of five, 2,6-difluorobenzylated 1,2,3-triazoles can be considered as potential candidates for further biological activity assays.

A new series of 3,6-disubstituted 2-(methylthio)-4-(trifluoromethyl)-3,4-dihydropyrimidin-4-ols displaying methyl, phenyl, aryl, and heteroaryl groups at the 6-position; and methyl, ethyl, allyl, and phenyl groups at the 3-position of the dihydropyrimidine ring, were synthesized and evaluated in vitro for acetylcholinesterase (AChE) inhibitory activity. Seven compounds showed activity with IC50 values in the lower micromolar range. The compound 4-trifluoromethyl-6-(4-fluorophenyl)-3-methyl-2-methylthio-3,4-dihydropyrimidin-4-ol (6e) had the best inhibitory activity (IC50 2.2±0.9 μM) and this inhibition was characterized as competitive. The molecular docking study showed that the AChE enzyme accommodates compound 6e in its catalytic site. The enantiomers of compound 6e, present similar interactions: π–π stacking interactions between the aromatic ring of the ligand's 4-fluorophenyl moiety and the aromatic rings of the electron-rich Trp84; and H-bonds between the hydroxyl group of Tyr121 and the hydroxyl moiety from 6e. The antioxidant effect of the dihydropyrimidin-4-ols was also investigated. This article is protected by copyright. All rights reserved.

This paper describes firstly an effective protocol for the synthesis of a new series of five examples of 3-(trifluoromethyl)-3,3a-dihydrospiro[chromeno[4,3-c]isoxazole-4,1′-cycloalkan]-3-ols (4), in which the cycloalkanes — cyclopentane, cyclohexane, cycloheptane, and 4′-methyl- and 4′-t-butyl-cyclohexane — were isolated at yields of 65–84%. The dihydro-isoxazolinols 4 were obtained regioselectively from the reactions of 2,2,2-trifluoro-1-[4-methoxy-spiro(2H-chromen-2,1′-cycloalkane)-3-yl]ethanones (3) with hydroxylamine hydrochloride, in the presence of sodium bicarbonate and methanol as solvent, for 24 h at 60 °C. The ethanone precursors 3 were synthesized by trifluoroacetylation reaction, employing trifluoroacetic anhydride and mixtures of enolethers and/or acetals derived from spiro[chroman-2,1′-cycloalkan]-4-ones (2) (Kabbe’s adducts), which were obtained beforehand from the reaction of cycloalkanones 1 with 2-hydroxyacetophenone and pyrrolidine. Subsequently, dehydration reactions of isoxazolinols 4, employing thionyl chloride and pyridine, enabled the isolation of another series of five novel spiro-isoxazoles 5 (76–95% yield). The structural features of the two series of new spiro heterocycles (4 and 5) were unequivocally determined with the aid of: one-dimensional 1H, 13C, and 19F NMR spectroscopy; two-dimensional 1H and 13C NMR spectroscopy (NOESY, gHMBC, and gHMQC); single crystal X-ray diffraction; and GC–MS.

Herein we report the synthesis of twelve 2,5-substituted 4-(trifluoromethyl)-spirochromeno[4,3-d]pyrimidines (7–10), as well as an evaluation of their analgesic effect in a mouse pain model. The nine new chromeno[4,3-d]pyrimidines (7–9) were synthesized from the cyclocondensation reactions of three 2,2,2-trifluoro-1-(4-methoxyspiro[chromene-2,1′-cycloalkane]-3-yl)ethanones (3) containing 5-, 6- and 7-membered spirocycloalkanes, with some well-known amidine salts (4–6) [NH2CR( NH)]—in which R = Me, Ph, and NH2—at yields of 60–95%. Subsequently, three new 2-(pyrrol-1-yl)-4-(trifluoromethyl)-chromeno[4,3-d]pyrimidines (10) were obtained through a Clauson-Kaas reaction between the respective 2-(amino)-4-(trifluoromethyl)-chromeno[4,3-d]pyrimidines (9) and 2,5-dimethoxy-tetrahydrofuran. The analgesic evaluation showed that these 4-(trifluoromethyl)chromeno[4,3-d]pyrimidines (100 mg/kg, p.o.) and Ketoprofen (100 mg/kg, p.o.) significantly reduced capsaicin-induced spontaneous nociception. Moreover, the 2-pyrrolyl-spirocyclohexane derivative 10b (100 and 300 mg/kg, p.o.) had an anti-allodynic effect comparable to Ketoprofen (100 and 300 mg/kg, p.o.) in the arthritic pain model, without causing locomotor alterations in the mice. These results suggest that the compound 10b is a promising molecule for new analgesic drugs in the treatment of pathological pain, such as in arthritis.

The objectives of this study were to evaluate tetrahydropyridine derivatives as efflux inhibitors and to understand the mechanism of action of the compounds by in silico studies. Minimum inhibitory concentration (MIC) determination, fluorometric methods and docking simulations were performed. The compounds NUNL02, NUNL09 and NUNL10 inhibited efflux, and NUNL02 is very likely a substrate of the transporter protein AcrB. Docking studies suggested that the mechanism of action could be by competition with substrate for binding sites and protein residues. We showed for the first time the potential of tetrahydropyridines as efflux inhibitors and highlighted compound NUNL02 as an AcrB-specific inhibitor. Docking studies suggested that competition is the putative mechanism of action of these compounds.

The nickel-catalyzed cyclization of in situ generated ortho-chlorobenzophenone hydrazone derivatives, to afford 3-(hetero)aryl-1H-indazoles, is documented for the first time. The product 1H-indazoles can be transformed subsequently in a one-pot procedure into 1,3-di(hetero)aryl-1H-indazoles via copper-catalyzed N-arylation with (hetero)aryl bromides.

Five new examples of 9,10-chloro(bromo)-7-amine-spiro[chromeno[4,3-b]quinoline-6,1′-cycloalkanes] — in which cycloalkanes = cyclopentane, cyclohexane, and cycloheptane — were synthesized at yields of 42–56%, using a sequential one-pot two-step cyclocondensation reaction of three different scaffolds of 2-aminobenzonitriles and the respective spiro[chroman-2,1′-cycloalkan]-4-ones, and using AlCl3 as the catalyst in a solvent-free method. Subsequently, the five new spirochromeno-quinolines and nine quinolines previously published by us (14 modified tacrine scaffolds) were subjected to AChE and BChE inhibitory activity evaluation. The molecule containing a spirocyclopentane derivative had the highest AChE and BChE inhibitory activity (IC50 = 3.60 and 4.40 μM, respectively), and in general, the non-halogenated compounds were better inhibitors of AChE and BChE than the halogenated molecules. However, the inhibitory potency of compounds 3a-n was weaker than that of tacrine. By molecular docking simulations, it was found that the size of the spirocarbocyclic moieties is inversely proportional to the inhibitory activity of the cholinesterases, probably because an increase in the size of the spirocyclic component sterically hindered the interaction of tacrine derivatives with the active site of tested cholinesterases. The findings obtained here may help in the design and development of new anticholinesterase drugs.

A new series of nine examples of 9-aryl-3-(aryl/heteroaryl)-1,1-difluoro-7-(trifluoromethyl)-1H-[1,3,5,2]oxadiazaborinino[3,4-a][1,8]naphthyridin-11-ium-1-uides, which contained 1,8-naphthyridine-based boron complexes with variable ligand structures, were synthesized at yields of 50–65% from the reaction of unpublished 2-benzoylamino-7-aryl(heteroaryl)-5-trifluoromethyl-1,8-naphthyridines—in which aryl(heteroaryl) = phenyl, 4-MeC6H4, 4-FC6H4, 4-BrC6H4, 4-OMeC6H4, 4-NO2C6H4, and 2-thienyl—with BF3·Et2O and fully characterized by 1H-, 13C-, 19F-, and 11B NMR spectroscopy and X-ray diffractometry. The optical and electrochemical properties of the new complexes were investigated, and the results for quantum yield calculations, Stokes shift, UV–vis, fluorescence, and redox potential data analysis indicated an important relationship with the aryl(heteroaryl) substituents attached to the 3- and 9-position of the naphthyridine boron complexes.

A facile and regioselective synthesis of a series of new methyl 3-ferrocenyl-1H-pyrrole-2-carboxylates obtained from methyl ferrocenyl azido acrylate and symmetrical or non-symmetrical 1,3-dicarbonyl compounds under microwave-assisted conditions is reported. 3-Ferrocenyl substituted pyrroles, which are normally difficult to obtain via the known reported methods, can now be regioselectively prepared by this protocol. Compared to already known acidic, basic, or metal-catalyzed methodologies for polysubstituted pyrrole synthesis, the present synthetic route is mild, quick, simple, and it furnishes new functionalized tetrasubstituted-pyrroles in short reaction times (30 min) and at satisfactory to good yields (32–75%).

A useful synthetic route for an initial new series of 2-substituted 4-(trifluoromethyl)-5,6-dihydrobenzo[h]quinazolines (3), as well as an evaluation of their analgesic effect in a mice pain model, is reported. Five new quinazolines were formed from the cyclocondensation reactions of 2,2,2-trifluoro-1-(1-methoxy-1,2,3,4-tetrahydronaphthalen-2-yl)ethanone (1) with some well-known amidine salts [NH2CR(=NH)] (2), in which R = H, Me, Ph, NH2 and SMe, at a 40–70% yield. Subsequently, due to the importance of the pyrrole nucleus, a 2-(pyrrol-1-yl)quinazoline (4) was obtained through a Clauson–Kaas reaction from the respective 2-(amino)quinazoline, in a reaction with 2,5-dimethoxy-tetrahydrofuran. The analgesic evaluation demonstrated that four 5,6-dihydrobenzo[h]quinazolines (compounds of 3c (R = Ph), 3d (R = NH2), 3e (R = SMe), and 4 (R = pyrrol-1-yl); 100 mg/kg, p.o.) and ketoprofen (100 mg/kg, p.o.) significantly reduced the spontaneous nociception in a capsaicin-induced test. Moreover, in comparison with ketoprofen (100 and 300 mg/kg, p.o.), compound 3c (30–300 mg/kg, p.o.) showed an anti-hyperalgesic action in an arthritic pain model without locomotor alterations in the mice, suggesting that quinazoline 3c is a promising prototype scaffold for new analgesic drugs in the treatment of pathological pain such as that in arthritis.

A convergent synthesis of a series of 16 new polysubstituted (5-hydroxy-5-(trifluoromethyl)-4,5-dihydro-1H-pyrazol-1-yl)(quinolin-4-yl)methanones, starting from isatin and alky(aryl/heteroaryl) ketones, is described. The diheteroaryl methanones were achieved at yields of up to 95% by a [3 + 2] cyclocondensation reaction involving 4-alkyl(aryl/heteroaryl)-4-methoxy-1,1,1-trifluorobut-3-en-2-ones (by two-step reaction) and 2-alkyl(aryl/heteroaryl)-4-carbohydrazides (by three-step reaction). Subsequently, representative dehydrated heterocyclic derivatives were obtained from the respective 5-hydroxy-2-pyrazoline moieties by classical dehydration reactions, which resulted in the corresponding (5-(trifluoromethyl)-1H-pyrazol-1-yl)(quinolin-4-yl)methanones (three examples) at yields of 69–82%. The subsequent cytotoxicity evaluation showed that compounds with aromatic groups at the 2-position of the quinoline and a methyl moiety at the 3-position of the pyrazole have significant cytotoxicity in human leukocytes at high concentrations (200 μM).

A mild and efficient protocol for the assembly of tetra-substituted 5-trifluoromethylpyrazoles is presented, involving halogenation at the 4-position of readily prepared tri-substituted 5-trifluoromethylpyrazoles to give 4-halo-1-phenyl-5-trifluoromethyl pyrazoles, and subsequent palladium-catalyzed Negishi or Buchwald-Hartwig cross-couplings to install carbon or nitrogen-based 4-substituents. Key to the success of these challenging cross-couplings is the use of XPhos and JosiPhos CyPF-tBu ligands, respectively.

This short study reports firstly the synthesis of a new series of six 1-substituted 6-((4,4,4-trihalo-3-oxo-alk-1-en-1-yl)amino)-2H-chromen-2-ones (4 and 5) and three 4- substituted 2,2-difluoro-3-(2-oxo-2H-chromen-6-yl)-6-(trichloromethyl)-2H-1,3,2-oxazaborinin-3-ium-2-uides (7), in which the selected 1- and 4-substituents are Me, Ph, and thien-2-yl. Both series (4 and 5) were synthesized from the reaction of 6-aminecoumarin (3) with (Z)-1,1,1-trihaloalk-3-en-2-ones (1 and 2), at 50–95 % yields. Subsequently, reactions of the coumarins 4 and 5 with boron (BF3·OEt2) gave only the corresponding 6-trichlorometylated heterocycles (7), at 65–78 % yields. Absorption and emission properties were investigated for the new coumarin derivatives. The results for UV–vis, emission fluorescence, quantum yield, and Stokes shift analysis indicated important relationships between the β-enaminone skeletons and their substituents.

The synthesis of 4-ethoxy-5-hydroxypyrrolidin-2-ones and 6-hydroxyhexahydro-4H-furo[2,3-c]pyrrol-4-ones — through the regio- and stereoselective reduction of the corresponding 3-alkoxysuccinimides — is described. The reaction used NaBH4 at low temperatures and short reaction times, providing products with yields of up to 77%. The stereoselectivity was highly influenced by both alkoxy and the N-moiety in the starting succinimide.

This Letter reports the first series of seven examples of novel 7-amine-spiro[chromeno[4,3-b]quinoline- 6,1′-cycloalkanes], where cycloalkane is cyclopentane, cyclohexane, cycloheptane, 2-methyl-, 3-methyl-, 4-methyl-, and 4-t-butyl-cyclohexane. These new compounds were synthesized at yields of 30–65% by a one-pot cyclocondensation reaction of 2-aminobenzonitrile and seven examples of spiro[chroman-2,1′-cycloalkan]-4-ones, using AlCl3 as the catalyst, without solvent and under conventional thermal heating. Subsequently, these spirochromeno-quinolines were subjected to AChE and cytotoxicity activity, and molecular docking studies. Both results for these new tacrine analogues were correlated with the structural features and showed the best results for the tacrine hybrid that possesses the spirocyclopentane moiety.

The results of the chemical behavior of three substituted cyanoacetylazoles and some salicylic aldehydes used to obtain new trifluoromethylated azolecarbonyl-2H-chromen-2-ones through Knoevenagel condensation reactions, are reported. First, a new series of four 3-(5-hydroxy-3-methyl-5-trifluoromethyl-4,5-dihydro-1H-pyrazole-1-carbonyl)-2-imino-2H-chromenes were efficiently synthesized, in yields of 50–78%, using 0.4 M NaOH/EtOH as the catalyst. They were then subjected to an acid hydrolysis reaction, which produced the respective trifluoromethyl-substituted pyrazolinecarbonyl coumarins in good yields (80–91%). In order to study the influence of the CF3 substituent, reactions involving 1-cyanoacetyl-3,5-dimethyl-5-hydroxy-4,5-dihydro-1H-pyrazole were also performed, but they did not provide the desired coumarins. On the other hand, attempts to synthesize some pyrrolecarbonyl coumarins not containing trifluoromethyl groups, but using the same methodology, directly resulted in a new series of five 3-(1-methyl-1H-pyrrol-2-carbonyl)-2H-chromen-2-ones in good yields (40–60%).

A new one-pot method, for the synthesis of polysubstituted pyrrolo[3,4- d ]pyridazinones, is presented. The protocol consists in cascade reactions performed in the same media: (i) the thermal in situ pyrrole formation by the reaction of vinyl azides with 1,3-dicarbonyl compounds, via the 1,2-addition of 1,3-dicarbonyl compounds to 2 H -azirine intermediates; (ii) the nucleophilic addition of hydrazines to the ketone group present in the pyrroles previously formed, followed by intramolecular cyclization with the bordering ester, which furnishes the respective pyrrolo[3,4- d ]pyridazinones, substituted at the pyrrole and/or pyridazinone rings. All transformations occur in a two-step one-pot methodology, and a series of ten new compounds were obtained at yields of 42–87%.

This paper reports a synthetic and NMR spectroscopic studies of two new series of 4-fluorinated 1,3,5-substituted 1H-pyrazoles. Firstly, an efficient synthesis of new series of 3-aryl-4-(di)fluoromethyl-1H-1-phenylpyrazoles, where [aryl = Ph, 4-NO2C6H4, 4-CH3OC6H4] is described, from fluorination reactions of 4-(formyl)- and 4-(hydroxymethyl)-1H-1-phenylpyrazoles in dichloromethane as solvent at room temperature, employing diethylaminosulfur trifluoride (DAST) as fluorinating agent in 41 to 73% yield. The 4-formyl-pyrazoles are obtained in 54–58% yield by Vilsmeier–Haack reaction using a mixture of POCl3/DMF with arylhydrazones, which were derived from the respective aryl methyl ketones and phenylhydrazine. The 4-hydroxymethyl-pyrazole precursors were easily obtained from the reduction of 4-formyl-pyrazoles by sodium borohydride (NaBH4) in 52–87% yield. Subsequently, the present work also discusses the 1H, 13C and 19F NMR spectroscopic data.

This work presents a new synthesis of the antiepileptic drug rufinamide—1-(2,6-difluorobenzyl)-1H-1,2,3-triazole-4-carboxamide) in chemical form—and some analogue compounds, through a one-pot reaction employing a solventless, metal-free catalysis and without any reducing reagent. The great novelty presented is the synthesis of 4-trichloroacetyl-1-(2,6-difluorobenzyl/benzyl/4-methoxybenzyl)-5-methyl(phenyl)-1H-1,2,3-triazoles as new precursors from a regioselective 1,3-dipolar cycloaddition reaction between 1,1,1-trichloro-4-alkoxyalk-3-en-2-ones and some benzyl azides, which are converted into rufinamide and the analogues by an addition–elimination reaction with an aqueous solution of NH4OH in good yields (42–52%).

This paper firstly describes an efficient and regioselective method for the synthesis of a new series of 2,2,2-trifluoro-1-[4-methoxy-spiro(2 H -chromen-2,1′-cycloalkane)-3-yl]ethanones from spiro[chroman-2,1′-cycloalkan]-4-ones (Kabbe's adduct). Yields of 38–61% were obtained when trifluoroacetylation reactions of mixtures of enolethers and/or acetals derived from four spiro ketones (Kabbe's adduct) were performed at a temperature of 45 °C, employing anhydrous chloroform as the solvent. Subsequently, when the respective trifluoroacetylated Kabbe adducts reacted with phenylhydrazine and methylhydrazine at a 1:1 molar ratio in refluxing ethanol for 24 h, a new series of seven examples of a new spiro-condensed heterocyclic system, namely 1(2)-methyl(phenyl)-3-(trifluoromethyl)-1,4(2,4)-dihydro-spiro(chromen[4,3- c ]pyrazole-4, n ′-cycloalkanes) – where cycloalkanes are cyclopentane, cyclohexane, and cycloheptane for n = 1; and tetrahydro-2 H -pyran for n = 2 – were isolated at yields of between 35% and 51%. Finally, the structures of new spiro heterocycles were determined with the aid and simultaneous application of 1 H, 13 C and 19 F one-dimensional and gHMBC NMR experiments, X-ray monocrystal diffraction, and mass spectrometry techniques.

Pain is the most common complaint in the medical field and the identification of novel compounds that can effectively treat painful states without causing side effects remains a major challenge in biomedical research. The aim of the present study is to investigate the antinociceptive effect of 3-(4-fluorophenyl)-5-trifluoromethyl-1H-1-tosylpyrazole (FTosPz) in models of pathological pain in mice and compare these effects with those produced by Celecoxib. FTosPz (100-500 μmol/kg) or Celecoxib (26-260 μmol/kg) was administrated orally. The administration of either FTosPz or Celecoxib reduced the hyperalgesia but not the edema or leukocyte infiltration that was caused by Complete Freund's Adjuvant (CFA), used as an arthritis model. Oral administration of both FTosPz and Celecoxib also attenuated the postoperative hyperalgesia as well as the hyperalgesia caused by partial sciatic nerve ligation, used as a neuropathic pain model. FTosPz and Celecoxib produced antinociceptive effects without altering the locomotor activity of animals. Furthermore, FTosPz neither altered AST/ALT enzyme activity nor the urea/creatinine levels. Still, the FTosPz did not alter the COX-1 and COX-2 enzyme activities. Thus, FTosPz is an interesting prototype for the development of novel analgesic drugs.

Acute lymphoblastic leukemia (ALL) is a malignant disorder caused by the proliferation of lymphoid progenitor cells and is the most common cancer in children. Cytotoxic nucleoside analogues are important chemotherapeutic agents, which are used in many cancers, including leukemias. In this study, we investigated the effects of the synthetic nucleoside analogue 1-(5,5,5-trichloro-2-methoxy-4-oxopenten-2-yl)-4-trichloromethyl-pyrimidin-2(1H)-one, named compound 3 or C3, on leukemia cell lines. The compound stimulated cell death by apoptosis, evidenced by DNA fragmentation, phosphatidylserine externalization, and caspase-3 activation. Compound 3 seemed to trigger several cell death pathways. The mitochondrial pathway was evidenced through a disturbance of mitochondrial membrane potential, strong cytochrome c liberation, decrease of antiapoptotic Bcl-2 protein expression, and caspase-9 activation. The C3 also induced caspase-8 and -12 activation, an increase in the intracellular calcium level, and an overproduction of reactive oxygen species. Increased caspase 8 activity suggests that the extrinsic pathway was activated and that the ROS production and enzyme activity alteration (glutathione S-transferase, glutathione peroxidase, catalase, and glutathione reductase) might be related to oxidative stress. Finally, the increase in calcium release, CHOP expression, and caspase-12 activity might characterize endoplasmic reticulum stress. Compound 3 was likewise cytotoxic to leukemic and melanoma human cell lines. Taken together, the results contribute to further understanding the new pyrimidine analogue as a potential chemotherapeutic drug or lead molecule.

The synthetic versatility of ethyl 2-(2-ethoxy-3,4-dihydro-2H-pyran-5-yl)-2-oxoacetate for the synthesis of ethyl 2-oxo-2-(1-alkyl/aryl-6-(amino/ethoxy)-1,4,5,6-tetrahydropyridin-3-yl)acetates, from the reaction with primary amines, is presented. The methodology proposed herein is highly chemoselective, and twenty products were obtained in moderate to good yields (up to 87%).

This paper describes an efficient method for synthesis of rufinamide analogs from the 1,3-dipolar cycloaddition and/or electrocyclization reactions under conventional thermal conditions of 4-alkyl(aryl/heteroaryl)-4-alkoxy-1,1,1-trifluoroalk-3-en-2-ones (1) with 2,6-difluorobenzyl azide, where 4-alkyl = H, Me; 4-aryl = Ph, 4-NO2C6H4, 4-OCH3C6H4, 4-FC6H4, 4,4′-BiPh; and 4-heteroaryl = 2-thienyl; for the efficient preparation of a series of ten new trifluoroacetyl(trifluoromethyl) substituted 1H-1,2,3-triazoles. Yields in the range of 30–71% were obtained when the reactions were performed at high temperatures (130–150 °C) under solvent-free conditions. The pure regioisomers or mixtures of triazoles could be isolate with dependency of the 4-substituent of the enones 1. Finally, two mechanisms are proposed and the results are discussed in accordance with the X-ray diffraction results and FMO theory, which describes the possible HOMO/LUMO interactions via DFT calculations for both precursors.

This paper describes firstly the synthesis of a new series of 3-hydroxy-2-[(3(5)-(methyl/phenyl)-5(3)-(trifluoromethyl)-1 H -pyrazol-4-yl)arylmethyl]-cyclohex-2-en-1-ones (2), where aryl = C 6 H 5 , 4-NO 2 C 6 H 4 , 4-OCH 3 C 6 H 4 , from an ANRORC ring transformation reaction of 3-acyl-4-aryl-2-(trifluoromethyl)-2-hydroxy-3,4,7,8-tetrahydro-2 H -chromen-5(6 H )-ones (1), where acyl = acetyl and benzoyl, in the presence of hydrazine hydrate, at 63–90% yields. In subsequent steps, an oxidative aromatization reaction from 2 was done in an iodine/methanol medium for the preparation of 3(5)-trifluoromethyl-5(3)-methyl-4-[(2,6-dimethoxyphenyl)-(4-methoxyphenylmethyl)]-1 H -pyrazole (3) at 72% yields. Also, the alkylation reaction using benzyl chloride easily converted a pyrazole like 2 to its N -benzyl derivative (4), at 69% yield. Finally, the structural assignment of compounds 2–4 was deduced by mass spectrometry, X-ray crystal diffraction and density functional theory (DFT) calculations, which clearly and unambiguously furnished values very close to those determined from 1 H, 13 C and 19 F NMR data.

This paper describes a mild method for regioselective reduction of 3-acyl-4-aryl-2-(trifluoromethyl)-2-hydroxy-3,4,7,8-tetrahydro-2 H -chromen-5(6 H )-ones, where acyl = Ac, Bz, 2-thenoyl; and aryl = Ph, 4-NO 2 C 6 H 4 , 4-OCH 3 C 6 H 4; employing sodium borohydride as the reducing reagent for successful preparation of a series of nine new 3-acyl-4-aryl-2-(trifluoromethyl)-8a-hydroxy-octahydrochromen-5-ones. Yields in the range of 25–63% were obtained when the reduction reactions were performed at room temperature using ethanol as the solvent. When 3-acetyl-2-hydroxy-5-methoxy-4-phenyl-2-(trifluoromethyl)chromane was also tested under similar conditions, the 3-(1-hydroxyethyl)-3,4-dihydro-2 H -chromane derivative was obtained at 83% yield. A representative X-ray diffraction ORTEP for an example of 2-(trifluoromethyl)-octahydrochromen-5-one is shown and the reduction mechanisms discussed.

An efficient one-pot transition metal-free procedure for the synthesis of new pyrazolo[1,5-a]quinoxalin-4(5H)-ones from easily prepared 1-(2-chlorophenyl-5-ethylcarboxylate)pyrazoles and various primary alkylamines is described. The key steps involved in the synthesis of the new 5,6-fused ring system are the formation of an amide intermediate followed by an intramolecular N-arylation reaction via nucleophilic aromatic substitution.

This paper describes the one-pot simple and efficient oxidative aromatization reaction employing an iodine/alcohol medium for the preparation of a series of 11 new 3-acyl-2-hydroxy-5-alkoxy-4-aryl-2-(trifluoromethyl)chromanes, where acyl = Ac, Bz, furan-2-oyl; aryl = Ph, 4-NO 2 C 6 H 4 , 4-OCH 3 C 6 H 4 and alkoxy = OMe, O-Pr n , EtO and OBn from the respective 3-acyl-4-aryl-2-(trifluoromethyl)-2-hydroxy-3,4,7,8-tetrahydro-2 H -chromen-5(6 H )-ones. Yields in the range of 50–89% were obtained when the oxidative reactions were performed using both conventional thermal heating (CTH) and microwave (MW) procedures. In general, the MW method produced similar yields with shorter reaction times and easier reaction workups. As an example, a representative X-ray diffraction ORTEP for 3-benzoyl-2-hydroxy-5-methoxy-4-methoxyphenyl-2-(trifluoromethyl)chromane is also shown.

A microwave-assisted synthesis of a series of 1-aryl-4-dimethylaminomethylene pyrrolidine-2,3,5-triones from the cyclocondensation reaction of ethyl 5,5,5-trichloro-3-dimethylamino methylene-2,4-dioxopentanoate with aniline, 3- or 4-substituted anilines [where the substituents = 3-Me, 3-OMe, 3-OH, 4-Me, 4-F, 4-Cl, 4-Br, 4-NO 2 , and 4-COMe] is reported. This process is an efficient alternative to the conventional thermal heating and furnishes the products in a short reaction time (ca. 13 min), under mild conditions and in moderate to good yields (50–76%).

A new series of twenty-one trifluoromethyl-containing ( E )- N ′-arylidene-1 H -pyrazole-1-carbohydrazides ( 4 ) was synthesized by the cyclocondensation reactions of six 3-alkyl(aryl/heteroaryl)-5-trifluoromethyl-5-hydroxy-4,5-dihydro-1 H -pyrazole-1-carbohydrazides ( 2 ) with eleven aryl/heteroaryl aldehydes and acetophenone ( 3 ) in 52–97% yields and six new carbohydrazides 2 were easily obtained from the reaction of 1,1,1-trifluoro-4-alkyl(aryl/heteroaryl)-4-methoxy-3-alken-2-ones ( 1 ) with carbohydrazide. Subsequently, four examples of carbohydrazides 4 were fully studied by X-ray diffraction and the twenty-seven pyrazolyl-carbohydrazides 2 and 4 screened for their antioxidant and antimicrobial proprieties and evaluated by DPPH and MIC methods, respectively. Both series 2 and 4 showed ability to capture DPPH free radical for IC 50 from 47.57 to 487 μg/mL. Most of the compounds presented fungistatic and bacteriostatic activity only for high MIC levels ranging from 0.25 mg/mL to 0.5 mg/mL.

This study describes a simple and efficient procedure to synthesize a novel series of fourteen 4-substituted N-(5-pyridinyl-1H-1,2,4-triazol-3-yl)-6-(trifluoromethyl)pyrimidin-2-amines, where the 4-substituents are H, CH3, C6H5, 4-FC6H4, 4-CH3C6H4, 4-CH3OC6H4 and 2-Furyl; from the cyclocondensation reaction of N-[5-(pyridinyl)-1H-1,2,4-triazol-3-yl]guanidines with 4-alkoxy-4-alkyl(aryl/heteroaryl)-1,1,1-trifluoroalk-3-en-2-ones. The reactions were carried out in ethanol under reflux for 18 h and led to 40–68% yields. N-(Pyridyl-triazolyl)guanidine precursors were further obtained from reactions of cyanoguanidine with nicotinic or isonicotinic acid hydrazides and the halogenated enones from trifluoroacetylation of enolethers or acetals.

The unexpected results of the cyclization reactions of N,N′-bis(oxotrifluoroalkenyl)-1,3-phenylenediamines [1,3-C6H4-(NHCR CHC(O)CF3)2], where R = H, Me, and Ph, in a strongly acidic medium (PPA), allowing the synthesis of new trifluoromethylated heterocycles containing the 1,7-phenanthroline nucleus in 32–40% yields and 7-aminoquinolines (38–40% yields), is reported. The bis-enaminoketone intermediates were easily isolated from the reactions of 4-alkoxy-4-alkyl(aryl)-1,1,1-trifluoroalk-3-en-2-ones with 1,3-phenylenediamine in ethanol under mild conditions (68–86% yields).

A series of NH-pyrazoles was efficiently synthesized from the reaction of b-dimethylaminovinylketones ([R 1 C(O)C(R 2 )@CHN(Me2)], where R

A series of sixteen 2-substituted-2-imidazolines (where the substituent R=Ph, Me-4-Ph; MeO-4-Ph; (MeO)(2)-3,4-Ph; (MeO)(3)-3,4,5-Ph; Ph-4-O-C(O)-Ph; Cl-4-Ph; Cl-2-Ph; Cl(2)-2,4-Ph; NO(2)-4-Ph; NO(2)-3-Ph; Naphth-2-yl; Fur-2-yl; Benzofur-2-yl; Pyridin-2-yl; Quinolin-2-yl) has been synthesized from the reaction of the substituted-aldehydes and ethylenediamine by ultrasound irradiation with NBS in an aqueous medium in high yields (80-99%). The 2-imidazoline ability to inhibit the activity of the A and B isoforms of monoamine oxidase (MAO) was investigated and some of them showed potent and selective MAO inhibitory activity especially for the MAO-B isoform and could become promising candidates for future development.

Six novel ω-brominated-2-trichloroacetylcycloalkanones were regiospecifically obtained in reactions from four 2-trichloroacetylcycloalkanones and bromine. 1H and 13C NMR data reveal that ω-brominated β-diketones are predominantly in keto–keto form.

The first synthesis of a series of 2-aryl(heteroaryl)-4-trifluoromethyl-4,5-dihydro-3H-pyrido[2,3-b][1,4]diazepin-4-ols, where aryl = C6H5, 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 4-CH3C6H4, 4-OCH3C6H4, 4,4′-biphenyl, 1-naphthyl and heteroaryl = 2-thienyl, 2-furyl obtained from the direct cyclocondensation reaction of 4-methoxy-1,1,1-trifluoroalk-3-en-2-ones with 2,3-diaminopyridine in 54–71% yield, is reported. Another alternative and efficient route for the synthesis of a series of 2-aryl(heteroaryl)-3H-pyrido[2,3-b][1,4]diazepin-4(5H)-ones from the reaction 4-methoxy-1,1,1-trichloroalk-3-en-2-ones with 2,3-diaminopyridine, in 54–70% yield, is also reported.