38489-80-4Relevant academic research and scientific papers
Design and synthesis of sinomenine isoxazole derivatives via 1,3-dipolar cycloaddition reaction
Pan, Hongmei,Lu, Tong,Wu, Xuedan,Gu, Chengwen,Tao, Naili,Zhang, Biao,Wang, Ao,Chen, Guangmei,Zhang, Kehua,Cheng, Jie,Jin, Jie
supporting information, p. 2360 - 2364 (2019/11/11)
A novel structure of sinomenine isoxazole derivatives is synthesised from sinomenine hydrochloride and aromatic aldehydes and requires six steps. 19 target compounds have been obtained in good yields. The sinomenine hydrochloride transforms to 4-alkynyl sinomenine, which is a key intermediate product to synthesise the target sinomenine isoxazole compounds, after a neutralisation reaction with ammonia and substitution reaction with 3-chloropropyne. Another key intermediate product is 1,3-dipole, which can be obtained from aromatic aldehyde. After treatment with hydroxylamine hydrochloride and then sodium carbonate solution, aromatic aldehyde is converted to aldehyde oxime, which reacts with N-chlorosuccinimide (NCS) to afford aryl hydroximino chloride. 1,3-Dipole is eventually formed in situ while triethylamine (TEA) in DMF is added dropwise. Then 4-alkynyl sinomenine is added to provide the sinomenine isoxazole derivative via 1,3-dipolar cycloaddition reaction as the key step. All the target compounds are characterised by melting point, 1H NMR, 13C NMR, HRMS and FT-IR spectroscopy.
HCl-mediated cascade cyclocondensation of oxygenated arylacetic acids with arylaldehydes: one-pot synthesis of 1-arylisoquinolines
Hsueh, Nai-Chen,Chen, Shin-Mei,Lin, Chun-Yi,Chang, Meng-Yang
, p. 1047 - 1059 (2021/02/16)
In this paper, a concise, open-vessel synthesis of 1-arylisoquinolines is describedviaHCl-mediated intermolecular cyclocondensation of oxygenated arylacetic acids with arylaldehydes in the presence of NH2OH and alcoholic solvents under mild and one-pot reaction conditions. A plausible mechanism is proposed and discussed herein. In the overall reaction process, only water was generated as the byproduct. Various environmentally friendly reaction conditions are investigated for convenient transformationviathe (4C + 1C + 1N) annulation. This protocol provides a highly effective ring closureviathe formations of one carbon-carbon (C-C) bond, two carbon-nitrogen (C-N) bonds and one carbon-oxygen (C-O) bond.
Site selective synthesis and anti-inflammatory evaluation of Spiro-isoxazoline stitched adducts of arteannuin B
Ur Rasool, Javeed,Sawhney, Gifty,Shaikh, Majeed,Nalli, Yedukondalu,Madishetti, Sreedhar,Ahmed, Zabeer,Ali, Asif
, (2021/10/16)
A library of new spiroisoxazoline analogues of arteannuin B was synthesized through 1, 3-dipolar cycloaddition in stereoselective fashion and consequently screened for anti-inflammatory activity in RAW 264.7 macrophage cells. Three potent analogues (8i, 8 m, and 8n) were found to attenuate the LPS induced release of cytokines IL-6 and TNF-α more potently than the parent molecule. Also, the inhibition of LPS induced nitric oxide production in these cells show moderate to high efficacy. None of the three potent molecules have altered the viability of RAW 264.7 cells following 48 h incubation suggesting that the inhibition of cytokines and nitric oxide production exhibited in the cells was not due to toxicity. In addition, these compounds exhibit an IC50 range of 0.17 μM-1.57 μM and 0.09 μM-0.35 μM for the inhibition of IL-6 release and nitric oxide production respectively. The results disclose potent inhibition of pro-inflammatory mediators which are encouraging and warrant further investigations to develop new therapeutic agents for inflammatory diseases.
On the mixed oxides-supported niobium catalyst towards benzylamine oxidation
Granato, álisson Silva,de Carvalho, Gustavo S. Gon?alves,Fonseca, Carla G.,Adrio, Javier,Leit?o, Alexandre A.,Amarante, Giovanni Wilson
, p. 118 - 125 (2020/09/11)
A series of mixed oxides-supported niobium-based catalysts has been synthesized and applied towards oxidation reactions of benzylamine derivatives. Under the optimized reaction conditions, the selectivity to oxime enhanced, leading to the main product with up to 72 %. Moreover, even α-substituted benzylamines were well tolerated and led to oximes in good isolated yields. It is important to mention; four equivalents of the harmless and inexpensive hydrogen peroxide were employed as oxidizing agent. Mechanism hypothesis suggested that the reaction proceed to selective benzylamine oxidation into nitroso intermediate, following by formation of the corresponding oxime tautomer mediated by an unstable water produced by NbOx supported catalyst. This consists the first mixed oxides-supported niobium-based catalyst for selective oxidation of benzylamines to oximes.
1,3-Dipolar Cycloaddition, HPLC Enantioseparation, and Docking Studies of Saccharin/Isoxazole and Saccharin/Isoxazoline Derivatives as Selective Carbonic Anhydrase IX and XII Inhibitors
D'Ascenzio, Melissa,Secci, Daniela,Carradori, Simone,Zara, Susi,Guglielmi, Paolo,Cirilli, Roberto,Pierini, Marco,Poli, Giulio,Tuccinardi, Tiziano,Angeli, Andrea,Supuran, Claudiu T.
, p. 2470 - 2488 (2020/03/31)
Two series of saccharin/isoxazole and saccharin/isoxazoline hybrids were synthesized by 1,3-dipolar cycloaddition. The new compounds showed to be endowed with potent and selective inhibitory activity against the cancer-related human carbonic anhydrase (hCA) IX and XII isoforms in the nanomolar range, while no affinity was encountered for off-targets, such as hCA I and II. Successive enantioseparation on a milligram scale of the most representative compounds led to the discovery that (S)-isomers were more potent than their corresponding (R)-enantiomers. Lastly, molecular modeling studies were conducted to define those structural requirements that were responsible for the discrimination among selected human isoforms of carbonic anhydrases. Two nanomolar hCA IX and XII inhibitors were also screened for their selective toxicity against non tumoral primary cells (fibroblasts) and against a breast adenocarcinoma cell line (MCF7) in hypoxic environment. The efficacious combination of these compounds with doxorubicin on MCF7 cells was demonstrated after 72 h of treatment.
Synthesis and SAR study of simple aryl oximes and nitrofuranyl derivatives with potent activity against Mycobacterium tuberculosis
Calixto, Stephane Lima,Carvalho, Guilherme da Silva Louren?o,Coimbra, Elaine Soares,Granato, Juliana da Trindade,Louren?o, Maria Cristina da Silva,Wardell, James,da Costa, Cristiane Fran?a,de Souza, Marcus Vinicius Nora
, p. 12 - 20 (2020/02/06)
Background: Oximes and nitrofuranyl derivatives are particularly important compounds in medicinal chemistry. Thus, many researchers have been reported to possess antibacterial, antiparasitic, insecticidal and fungicidal activities. Methods: In this work, we report the synthesis and the biological activity against Mycobacterium tuberculosis H37RV of a series of fifty aryl oximes, ArCH=N-OH, I, and eight nitrofuranyl compounds, 2-nitrofuranyl-X, II. Results: Among the oximes, I: Ar = 2-OH-4-OH, 42, and I: Ar = 5-nitrofuranyl, 46, possessed the best activity at 3.74 and 32.0 μM, respectively. Also, 46, the nitrofuran compounds, II; X = MeO, 55, and II: X = NHCH2Ph, 58, (14.6 and 12.6 μM, respectively), exhibited excellent biological activities and were non-cytotoxic. Conclusion: The compound 55 showed a selectivity index of 9.85. Further antibacterial tests were performed with compound 55 which was inactive against Enterococcus faecalis, Klebisiella pneumonae, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhymurium and Shigel-la flexneri. This study adds important information to the rational design of new lead anti-TB drugs. Structure-activity Relationship (SAR) is reported.
Unusual Reactivity of 4-Vinyl Isoxazoles in the Copper-Mediated Synthesis of Pyridines, Employing DMSO as a One-Carbon Surrogate
Kumar, Pravin,Kapur, Manmohan
supporting information, p. 5855 - 5860 (2020/07/30)
An efficient protocol for the synthesis of nicotinate derivatives and tetrasubstituted pyridines through a copper-mediated cleavage of isoxazoles has been developed. The highlight of the work is the observation of an unusual reactivity of 4-vinyl isoxazoles under the reaction conditions. DMSO serves as a one-carbon surrogate generating an active methylene group during the reaction to form two C-C bonds. This protocol provides a facile and an expeditious approach for the assembly of densely substituted N-heterocyclic compounds.
Design, synthesis of novel 4,5-dihydroisoxazole-containing benzamide derivatives as highly potent FtsZ inhibitors capable of killing a variety of MDR Staphylococcus aureus
Song, Di,Bi, Fangchao,Zhang, Nan,Qin, Yinhui,Liu, Xingbang,Teng, Yuetai,Ma, Shutao
supporting information, (2020/09/11)
Antibiotic resistance among clinically significant bacterial pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant S. aureus (VRSA) is becoming a prevalent threat to public health, and new antibacterial agents with novel mechanisms of action hence are in an urgent need. As a part of continuing effort to develop antibacterial agents, we rationally designed and synthesized two series of 4,5-dihydroisoxazol-5-yl and 4,5-dihydroisoxazol-3-yl-containing benzamide derivatives that targeted the bacterial cell division protein FtsZ. Evaluation of their activity against a panel of Gram-positive and -negative pathogens revealed that compound A16 possessing the 4,5-dihydroisoxazol-5-yl group showed outstanding antibacterial activity (MIC, ≤0.125–0.5 μg/mL) against various testing strains, including methicillin-resistant, penicillin-resistant and clinical isolated S. aureus strains. Besides, further mouse infection model revealed that A16 could be effective in vivo and non-toxic to Hela cells. Finally, a detailed discussion of structure-activity relationships was conducted, referring to the docking results. It is worth noting that substituting a 4,5-dihydroisoxazole ring for the isoxazole ring not only broadened the antibacterial spectrum but also resulted in a significant increase in antibacterial activity against S. aureus strains. Taken together, these results suggest a promising chemotype for the development of new FtsZ-targeting bactericidal agents.
Synthesis and in vitro evaluation of neutral aryloximes as reactivators of Electrophorus eel acetylcholinesterase inhibited by NEMP, a VX surrogate
Cavalcante, Samir F. de A.,Kitagawa, Daniel A.S.,Rodrigues, Rafael B.,Bernardo, Leandro B.,da Silva, Thiago N.,dos Santos, Wellington V.,Correa, Ana Beatriz de A.,de Almeida, Joyce S.F.D.,Fran?a, Tanos C.C.,Ku?a, Kamil,Simas, Alessandro B.C.
, (2019/06/24)
Casualties caused by nerve agents, potent acetylcholinesterase inhibitors, have attracted attention from media recently. Poisoning with these chemicals may be fatal if not correctly addressed. Therefore, research on novel antidotes is clearly warranted. Pyridinium oximes are the only clinically available compounds, but poor penetration into the blood-brain barrier hampers efficient enzyme reactivation at the central nervous system. In searching for structural factors that may be explored in SAR studies, we synthesized and evaluated neutral aryloximes as reactivators for acetylcholinesterase inhibited by NEMP, a VX surrogate. Although few tested compounds reached comparable reactivation results with clinical standards, they may be considered as leads for further optimization.
Catalyst control in positional-selective C-H alkenylation of isoxazoles and a ruthenium-mediated assembly of trisubstituted pyrroles
Kumar, Pravin,Kapur, Manmohan
supporting information, p. 2134 - 2138 (2019/03/26)
High levels of catalyst control are demonstrated in determining the positional selectivity in C-H alkenylation of isoxazoles. A cationic rhodium-mediated, strong-directing group promotes C(sp2)-H activation at the proximal aryl ring whereas, the palladium-mediated electrophilic metallation leads to the C(sp2)-H activation at the distal position of the directing group. Synthetic elaboration of this C-H alkenylation product via ruthenium and copper co-catalysis leads to an efficient method for the assembly of densely substituted pyrroles.
