- Vanadium pentoxide as a catalyst for regioselective nitration of organic compounds under conventional and nonconventional conditions
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Vanadium pentoxide is used as an efficient catalyst for regioselective nitration of aromatic compounds under conventional and nonconventional conditions such as ultrasonically assisted (USAR) and microwave-assisted reactions (MWAR). The reactions underwent smoothly and afforded good yields of products with high regioselectivity. Observed longer reaction times (about 8 h) in V2O5 catalyzed reactions reduced to (0.5/30 min) under sonication and (90 s) in the case of MWAR. When ortho position is blocked, para derivatives are obtained as end products while ortho nitro products are obtained when para position is blocked.
- Venkatesham,Reddy, K. Rajendar,Rajanna,Veerasomaiah
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p. 921 - 926
(2014/04/03)
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- Oxalylchloride/DMF as an efficient reagent for nitration of aromatic compounds and nitro decarboxylation of cinnamic acids in presence of KNO 3 or NaNO2 under conventional and nonconventional conditions
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Nitration of aromatic compounds and cinnamic acids with oxalylchloride/DMF afforded the corresponding nitro derivatives in the presence of KNO3 or NaNO2 under conventional and nonconventional (ultrasonic and microwave) conditions. The present methodology offers several benefits such as excellent yields, simple work-up procedure, and short reaction times. The yields obtained under present methodology are comparable with those obtained from (POCl3/DMF/KNO3 or NaNO2) and (SOCl 2/DMF/KNO3 or NaNO2) systems followed by shorter reaction times. The reaction times of sonication and microwave conditions are very shorter than those of the conventional conditions.
- Kumar, M. Satish,Reddy, K. Rajendar,Rajanna,Venkanna,Krishnaiah
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p. 977 - 983
(2013/06/05)
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- Topoisomerase I-mediated antiproliferative activity of 10-substituted and 12-substituted homocamptothecins
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Homocamptothecin (hCPT) is an E-ring modified camptothecin (CPT) analogue, which showed pronounced inhibitory activity of topoisomerase I. In search of novel hCPT-type anticancer agents, two series of hCPT derivatives were synthesized and evaluated in vitro against three human tumor cell lines. The results indicated that the 10-substituted hCPT derivatives had a considerably higher cytotoxic activity than the 12-substituted ones. Among the 10-substituted compounds, 8a, 8b, 9b, and 9i showed an equivalent or even more potent activity than the positive control drug topotecan against the lung cancer cell line A-549. Moreover, the hCPT analogues 8a and 8b exhibited a higher topoisomerase I inhibitory activity than CPT at a concentration of 100 μM. Copyright
- Guo, Wei,Liu, Wenfeng,Zhu, Lingjian,Zhang, Yongqiang,Cheng, Pengfei,Dong, Guoqiang,Zhuang, Chunlin,Yao, Jianzhong,Sheng, Chunquan,Miao, Zhenyuan,Zhang, Wannian
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experimental part
p. 1539 - 1549
(2011/11/05)
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- Synthesis and pharmacological activity of 1,3,6-trisubstituted-4-oxo-1,4- dihydroquinoline-2-carboxylic acids as selective ETA antagonists
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A series of 1,3,6-trisubsituted-4-oxo-1,4-dihyroquinoline-2-carboxylic acid analogs (2a-m) were designed and synthesized and their pharmacological activity determined, with the objective to better understand their SAR as potential ETA selective inhibitors. Most of the compounds displayed significant ETA antagonist activity having IC50 for inhibition of binding of the [125I]ET-1 to ETA receptor A antagonism over ETB receptor. Based on the in vitro results, SAR of this series of compounds requires an alkoxy substituent at the 6-position to be a straight and saturated chain up to three carbons long, since substitution of unsaturated and branched alkyloxy groups results in decrease in ETA antagonist activity. In this series, compound 2c (6-O-n-propyl analog) was found to be most potent (IC 50 = 0.11 nM) with ETB/ETA selectivity of 8303.
- Patel, Hardik J.,Olgun, Nicole,Lengyel, István,Reznik, Sandra,Stephani, Ralph A.
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supporting information; experimental part
p. 6840 - 6844
(2011/01/04)
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- Design, synthesis, photochemical properties and cytotoxic activities of water-Soluble caged L-Leucyl-L-leucine methyl esters that control apoptosis of immune cells
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L-Leucyl-L-leucine methyl esters (LeuLeuOMe) is a lysosomotropic agent that induces apoptosis of certain immune cells. Glucose-carrying 2-nitrobenzyl (2-NB) and 2-nitrophenethyl (2-NPE) caged LeuLeuOMe, 1a and b, were synthesized and their photochemical a
- Mizuta, Hironori,Watanabe, Soichiro,Sakurai, Yuji,Nishiyama, Keiko,Furuta, Toshiaki,Kobayashi, Yoshiro,Iwamura, Michiko
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p. 675 - 683
(2007/10/03)
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- Synthesis of 4-acetylbenzoxazolin-2(3H)-one reported from Zea mays
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A three-step alternative synthesis of 4-acetylbenzoxazolin-2(3H)-one (4) is reported. Starting from inexpensive 3-hydroxyacetophenone (1) 3-hydroxy- 2-nitroacetophenone (2) is prepared by nitration followed by catalytic hydrogenation to yield 2-amino-3-hydroxyacetophenone (3) in which a C=O unit is inserted by means of bis(trichloromethyl)carbonate (triphosgene) in the presence of triethylamine to afford 4 in 35% overall yield.
- Kluge,Sicker
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p. 821 - 822
(2007/10/03)
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