115846-97-4Relevant academic research and scientific papers
Alkylation of 6-C(O)R-7-aryl-5-methyl-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidines
Kolosov, Maksim A.,Shvets, Elena H.,Kulyk, Olesia G.,Orlov, Valeriy D.
, p. 1052 - 1056 (2015)
Alkylation of 6-C(O)R-7-aryl-5-methyl-4,7-dihydro[1,2,4]triazolo[1,5-a]pyrimidines with methyl iodide or ethyl bromide in either saturated aqueous KOH–MeCN or NaH–DMF led to the formation of N4-alkyl derivatives in good yields (60–98%). Reactivity of the acetyl group of N4-alkyl derivatives towards aromatic aldehydes under the conditions of the Claisen–Schmidt reaction was significantly higher than in 4-unsubstituted compounds. The starting 6-C(O)R-7-aryl-5-methyl-4,7-dihydro[1,2,4]triazolo[1,5-a]pyrimidines were synthesized via a three-component condensation of an aromatic aldehyde, 3-amino-1,2,4-triazole, and a dicarbonyl compound (2,4-pentanedione or ethyl acetoacetate) in DMF.
Antibacterial activity of a new monocarbonyl analog of curcumin MAC 4 is associated with divisome disruption
Polaquini, Carlos R.,Marques, Beatriz C.,Ayusso, Gabriela M.,Mor?o, Luana G.,Sardi, Janaína C.O.,Campos, Débora L.,Silva, Isabel C.,Cavalca, Lúcia B.,Scheffers, Dirk-Jan,Rosalen, Pedro L.,Pavan, Fernando R.,Ferreira, Henrique,Regasini, Luis O.
, (2021)
Curcumin (CUR) is a symmetrical dicarbonyl compound with antibacterial activity. On the other hand, pharmacokinetic and chemical stability limitations hinder its therapeutic application. Monocarbonyl analogs of curcumin (MACs) have been shown to overcome these barriers. We synthesized and investigated the antibacterial activity of a series of unsymmetrical MACs derived from acetone against Mycobacterium tuberculosis and Gram-negative and Gram-positive species. Phenolic MACs 4, 6 and 8 showed a broad spectrum and potent activity, mainly against M. tuberculosis, Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus (MRSA), with MIC (minimum inhibitory concentration) values ranging from 0.9 to 15.6 μg/mL. The investigation regarding toxicity on human lung cells (MRC-5 and A549 lines) revealed MAC 4 was more selective than MACs 6 and 8, with SI (selectivity index) values ranging from 5.4 to 15.6. In addition, MAC 4 did not demonstrate genotoxic effects on A549 cells and it was more stable than CUR in phosphate buffer (pH 7.4) for 24 h at 37 °C. Fluorescence and phase contrast microscopies indicated that MAC 4 has the ability to disrupt the divisome of Bacillus subtilis without damaging its cytoplasmic membrane. However, biochemical investigations demonstrated that MAC 4 did not affect the GTPase activity of B. subtilis FtsZ, which is the main constituent of the bacterial divisome. These results corroborated that MAC 4 is a promising antitubercular and antibacterial agent.
Antibacterials and antimycotics: Part 1: Synthesis and activity of 2- pyrazoline derivatives
Nauduri, Dhananjaya,Reddy, Gopu Bala Show
, p. 1254 - 1260 (1998)
A series of 3-styryl-1,5-diphenyl and 5-styryl-1,3-diphenyl 2- pyrazolines of different substitutions has been synthesized by condensation of substituted α,β-unsaturated ketones with phenylhydrazine hydrochloride in presence of catalytic amount of concentrated HCl. Compounds in the 3- styryl series had OMe, NMe2, NO2, OH and isopropyl substituents and those in the 5-styryl series had OMe, NMe2 and NO(s). The 3-styryl-1,5-diphenyl compounds showed little variation in antibacterial activity towards gram- positive and gram-negative bacteria in terms of geometric mean minimum inhibitory concentrations (MIC). The 4',4-NMe2, 4',4-NO2 and 4',4-OMe compounds were found to possess the highest activity in the series. The 5- styryl-1,3-diphenyl series showed lower activities than the 3-styryl series. The in vitro antimycotic activity of the 4',4-OH and 2',2-OH substituted compounds showed good activity than the other molecules in the two series.
A Broad-Spectrum Synthesis of Tetravinylethylenes
Horvath, Kelsey L.,Newton, Christopher G.,Roper, Kimberley A.,Ward, Jas S.,Sherburn, Michael S.
supporting information, p. 4072 - 4076 (2019/03/22)
The first general synthesis of compounds of the tetravinylethylene (TVE) family is reported. Ramirez-type dibromo-olefination of readily accessible penta-1,4-dien-3-ones generates 3,3-dibromo[3]dendralenes, which undergo twofold Negishi, Suzuki–Miyaura or Mizoroki–Heck reactions with a wide variety of olefinic coupling partners. This route delivers a broad range of unsymmetrically substituted tetravinylethylenes with up to three different alkenyl substituents attached to the central C=C bond. The extensive scope of the approach is demonstrated by the preparation of the first higher order oligo-alkenic through-conjugated/cross-conjugated hybrid compounds. An unsymmetrically substituted TVE is shown to undergo a domino electrocyclization–cycloaddition with high site-selectivity and diastereoselectivity, thereby demonstrating the substantial synthetic potential of substituted TVEs for controlled, rapid structural complexity generation.
Activation of anti-oxidant Nrf2 signaling by enone analogues of curcumin
Deck, Lorraine M.,Hunsaker, Lucy A.,Vander Jagt, Thomas A.,Whalen, Lisa J.,Royer, Robert E.,Vander Jagt, David L.
, p. 854 - 865 (2017/12/13)
Inflammation and oxidative stress are common in many chronic diseases. Targeting signaling pathways that contribute to these conditions may have therapeutic potential. The transcription factor Nrf2 is a major regulator of phase II detoxification and anti-oxidant genes as well as anti-inflammatory and neuroprotective genes. Nrf2 is widespread in the CNS and is recognized as an important regulator of brain inflammation. The natural product curcumin exhibits numerous biological activities including ability to induce the expression of Nrf2-dependent phase II and anti-oxidant enzymes. Curcumin has been examined in a number of clinical studies with limited success, mainly owing to limited bioavailability and rapid metabolism. Enone analogues of curcumin were examined with an Nrf2 reporter assay to identify Nrf2 activators. Analogues were separated into groups with a 7-carbon dienone spacer, as found in curcumin; a 5-carbon enone spacer with and without a ring; and a 3-carbon enone spacer. Activators of Nrf2 were found in all three groups, many of which were more active than curcumin. Dose-response studies demonstrated that a range of substituents on the aromatic rings of these enones influenced not only the sensitivity to activation, reflected in EC50 values, but also the extent of activation, which suggests that multiple mechanisms are involved in the activation of Nrf2 by these analogues.
Gram-scale preparation of dialkylideneacetones through Ca(OH)2-catalyzed Claisen-Schmidt condensation in dilute aqueous EtOH
Zhang, Hao,Han, Mengting,Yang, Chenggen,Yu, Lei,Xu, Qing
, (2018/02/06)
A synthetic method of dialkylideneacetones has been developed. Compared with known protocols, the method employed catalytic Ca(OH)2 as the cheap, mild base catalyst and dilute aqueous EtOH (20%, v/v) as the green and safe solvent. The procedure was easily operated: In most cases, the product could be isolated by a simple filtration, and purified by washing with water. This paper provided experimental details of the reactions, which could be applied in gram-scale synthesis and should be a very reliable and practical protocol to prepare these useful compounds in laboratory and at the industrial level.
Further studies on anti-invasive chemotypes: An excursion from chalcones to curcuminoids
Roman, Bart I.,De Ryck, Tine,Verhasselt, Sigrid,Bracke, Marc E.,Stevens, Christian V.
, p. 1027 - 1031 (2015/02/19)
In our ongoing search for new anti-invasive chemotypes, we have made an excursion from previously reported potent 1,3-diarylpropenones (chalcones) to congeners bearing longer linkers between the aromatic moieties. Nine 1,ω-diarylalkenones, including curcumin and bisdemethoxycurcumin, were evaluated in the chick heart invasion assay. Unfortunately, these compounds proved less potent and more toxic than earlier evaluated chemotypes. In the 1,3-diarylpenta-2,4-dien-1-one series, fluoro and/or trimethoxy substitution caused an increase in potency. This agrees with observations made earlier for the chalcone class.
Oxygen as single oxidant for two steps: Base-free one-pot Pd(ii)-catalyzed alcohol oxidation & arylation to halogen-intact β-aryl α,β-enones
Vellakkaran, Mari,Andappan, Murugaiah M. S.,Nagaiah, Kommu
, p. 45490 - 45494 (2014/12/10)
Using oxygen as the sole oxidant for two steps, we developed a new method to synthesize β-aryl α,β-enones by fine-tuning the Pd(ii)-catalyzed oxidation of allyl alcohol to subsequent arylation with arylboronic acids, arylboronic ester and aryltrifluoroborate salt. This one-pot green method does not require copper salt, base, and intermediate isolation. Halogen-bearing chalcones, dibenzylideneacetones and arylalkyl enones were synthesized in good yields. This journal is
Catalytic asymmetric synthesis of spirocyclic azlactones by a double Michael-addition approach
Weber, Manuel,Frey, Wolfgang,Peters, René
supporting information, p. 8342 - 8351 (2013/07/27)
Spirocyclic azlactones are shown to be useful precursors of cyclic quaternary amino acids, such as the constrained cyclohexane analogues of phenylalanine. These compounds are of interest as building blocks for the synthesis of artificial peptide analogues with controlled folds in the peptide backbone. They were prepared in the present study by a step- and atom-economic catalytic asymmetric tandem approach, requiring two steps starting from N-benzoyl glycine and divinylketones. The key of this protocol is the enantioselective formation of the azlactone spirocycles, which involves a PdII-catalyzed double 1,4-addition of an in situ generated azlactone intermediate to the dienone (a formal [5+1] cycloaddition). As the catalyst, a planar chiral ferrocene bispalladacycle was used. Mechanistic studies suggest a monometallic reaction pathway. Although the diastereoselectivity was found to be moderate, the enantioselectivity is usually high for the formation of the azlactone spirocycles, which contain up to three contiguous stereocenters. Spectroscopic studies have shown that the spirocycles often prefer a twist over a chair conformation of the cyclohexanone moiety. A formal [5+1] cycloaddition of divinylketones and an in situ-generated glycine-derived azlactone was catalyzed by a chiral bis-palladacycle and provided highly enantioenriched, spirocyclic, masked amino acid products. The latter were used to synthesize biologically interesting constrained cyclohexane analogues of phenylalanine in just two steps (see scheme). Copyright
Synthesis of 2-(1,5-diaryl-1,4-pentadien-3-ylidene)- hydrazinecarboximidamide hydrochloride catalyzed by p-dodecylbenzenesulfonic acid in aqueous media under ultrasound irradiation
Li, Ji-Tai,Du, Chao,Xu, Xiao-Ya,Chen, Guo-Fen
experimental part, p. 1033 - 1038 (2012/07/03)
Amidinohydrazone compounds are very important synthetic intermediates and can serve as versatile precursors in synthesis of many natural products and drug molecules. The use of ultrasound, p-dodecylbenzenesulfonic acid (DBSA) and water as solvent improved the synthesis of different 2-(1,5-diaryl-1,4- pentadien-3-ylidene)-hydrazinecarboximidamide hydrochlorides. The best reaction conditions for the condensation of 1,5-diphenyl-1,4-pentadien-3-one with aminoguanidine hydrochloride were as follows: 1,5-diphenyl-1,4-pentadiene-3-one (1, 1 mmol), aminoguanidine hydrochloride (1.1 mmol), DBSA (0.5 mmol), water 10 mL, reaction temperature 25-27°C, irradiation frequency 25 kHz. 2a was achieved in 94% yield within 2 h. The other seven amidinohydrazones were obtained in 84-94% yield within 2-3 h under the same conditions. Compared to the method involving catalysis by hydrochloric acid in refluxing EtOH, the advantages of present procedure are milder conditions, shorter reaction times, higher yields, and environmental friendly conditions, which make it a useful strategy for the synthesis of analogues.
