Search results for "Nitrobenzene"
showing 10 items of 126 documents
Synthesis of pyrido[2,3-d]pyrimidinones by the reaction of aminopyrimidin-4-ones with benzylidene meldrum's acid derivatives
1997
A series of pyrido[2,3-d]pyrimidine-4,7-diones 5a-h were prepared from 6-amino-4-pyrimidones 1 and benzylidene Meldrum's acid derivatives 2 by cyclization reactions in boiling nitrobenzene. The structure of 5, determined by nmr measurements, reveals a selective orientation of 1 and 2 in the addition step.
ChemInform Abstract: Synthesis of Pyrido(2,3-d)pyrimidinones by the Reaction of Aminopyrimidin-4-ones with Benzylidene Meldrum′s Acid Derivatives.
2010
A series of pyrido[2,3-d]pyrimidine-4,7-diones 5a-h were prepared from 6-amino-4-pyrimidones 1 and benzylidene Meldrum's acid derivatives 2 by cyclization reactions in boiling nitrobenzene. The structure of 5, determined by nmr measurements, reveals a selective orientation of 1 and 2 in the addition step.
Growth of polyoxymethylene crystals during cationic polymerization of trioxane in nitrobenzene
1973
Predominant pathogenic role of tumor necrosis factor in experimental colitis in mice
1997
Antibodies to tumor necrosis factor (TNF)-alpha have been recently proposed as effective treatment for patients with Crohn's disease. Here, we analyze the functional role of TNF-alpha in a mouse model of chronic intestinal inflammation induced by the hapten reagent 2,4,6,-trinitrobenzene sulfonic acid (TNBS) that mimics some characteristics of Crohn's disease in humans. Macrophage-enriched lamina propria (LP) mononuclear cells from mice with TNBS-induced colitis produced 10-30-fold higher levels of TNF-alpha mRNA and protein than cells from control mice. When mice with chronic colitis were treated by intraperitoneal injection of antibodies to TNF-alpha, an improvement of both the clinical a…
Transcript profiling identifies novel key players mediating the growth inhibitory effect of NS-398 on human pancreatic cancer cells
2010
Pancreatic cancer is one of the most aggressive human malignancies with an increasing incidence worldwide. Despite an increase in the number of systemic treatments available for pancreatic cancer, the impact of therapy on the clinical course of the disease has been modest, underscoring an urgent need for new therapeutic options. Although selective cyclooxygenase-2 inhibitors have been demonstrated to have cancer-preventive effects, the mechanism of their effects is not clearly known. Moreover, there have been no unbiased studies to identify novel molecular targets of NS-398 regarding pancreatic cancer. Here we undertook a gene expression profiling study to identify novel molecular targets m…
Similar chemical structures, dissimilar triplet quantum yields: a CASPT2 model rationalizing the trend of triplet quantum yields in nitroaromatic sys…
2019
The photophysics of nitroaromatics compounds stand out for being characterized by an ultrafast decay into the triplet manifold and by a significant value of the triplet quantum yield. The latter quantity can change dramatically from one system to another, as proven for the molecules 2- nitronaphthalene, 1-nitronaphthalene, and 2methyl-1nitronaphthale, whose triplet quantum yield have been previously measured to be 0.93 ± 0.15, 0.64 ± 0.12, and 0.33 ± 0.05, respectively (J. Phys. Chem. A 2013, 117, 14100). In the present contribution we rationalize the reported trend for the triplet quantum yield on the basis of the different ability that the excited S 1 state has in the three molecules to r…
Highly selective and sensitive chromo-fluorogenic detection of the Tetryl explosive using functional silica nanoparticles
2011
Silica nanoparticles containing polyamines and thiol groups have been used as probes for the selective detection of Tetryl. © 2011 The Royal Society of Chemistry.
A new pyrazolo pyrimidine derivative inhibitor of cyclooxygenase-2 with anti-angiogenic activity
2003
In a previous study, we reported a new pyrazolo pyrimidine derivative, N(4)-benzyl-N(6),N(6)-dimethyl-1-1(tert-butyl)-1H-pyrazolo[3,4-d]pyrimidine-6,4-diamine (DPP), which inhibited potently cyclooxygenase-2 activity in intact cell assays with minor activity against cyclooxygenase-1 (IC(50)=0.9 nM for cyclooxygenase-2 versus IC(50)=59.6 nM for cyclooxygenase-1). In the present work, this behaviour was confirmed in vivo by using the 24-h zymosan-injected mouse air pouch model (ID(50)=1.36 nM/pouch for prostaglandin E(2) level). We also studied the possible beneficial effect of DPP in the angiogenesis-dependent murine air pouch granuloma and rat paw carrageenan-induced hyperalgesia models. DP…
Raloxifene increases the capacity of serum to promote prostacyclin release in human endothelial cells: implication of COX-1 and COX-2.
2004
OBJECTIVE Prostacyclin is a potent vasodilator synthesized by two isoforms of cyclooxygenase in endothelium. The aim of this study was to investigate the effect of serum from postmenopausal women treated with raloxifene on prostacyclin production by human umbilical vein endothelial cells and on cyclooxygenases-1 and -2. DESIGN Serum was collected from 21 women receiving 60 mg/day of raloxifene, at baseline and at 3 and 6 months. Human umbilical vein endothelial cells were exposed to serum for 24 hours, and prostacyclin production was evaluated in supernatants. Selective inhibitors of cyclooxygenases-1 and -2 (SC-560 and NS-398) were used to investigate the relative contribution of each enzy…
Selectivity of hydroxyl radical in the partial oxidation of aromatic compounds in heterogeneous photocatalysis
2007
Abstract The photocatalytic oxidation of different benzene derivatives has been investigated in order to understand how the substituent group affects the selectivity to hydroxylated compounds. Experimental runs were performed by using TiO2 (Merck) aqueous suspensions at natural pH irradiated by near-UV light. The organic molecules used as substrate contained an electron withdrawing group (EWG) (nitrobenzene, cyanobenzene, benzoic acid, 1-phenylethanone), an electron donor one (EDG) (phenol, phenylamine, N-phenylacetamide) or both an EWG and an EDG (4-chlorophenol). The results clearly indicated that the primary photocatalytic oxidation of aromatic compounds containing an EDG gives rise main…