Search results for "arrangement."
showing 10 items of 343 documents
Looking for a new panacea in ALK-rearranged NSCLC: may be Ceritinib?
2014
Abstract: In the past decade, the advent of targeted therapy led to a silent revolution in the war against lung cancer and a significant evolution on the concept of Phase I clinical trials design. Thanks to the specificity of their target, the new drugs have radically changed NSCLC treatment, leading to the development of personalized strategies. The accelerated approval of the first ALK-inhibitor, Crizotinib and more recently Ceritinib, without a Phase III randomized, clinical trial, has been an amazing success story in lung cancer research, marking the beginning of a new decade of targeted drugs development, characterized by modern, biomarker-driven, early clinical trial design and shorte…
On the Rearrangement in Dioxane/Water of (Z)-Arylhydrazones of 5-Amino-3-benzoyl-1,2,4-oxadiazole into (2-Aryl-5-phenyl-2H-1,2,3-triazol-4-yl)ureas: …
2006
We have recently evidenced an interesting differential behavior in the reactivity in dioxane/water between the (Z)-2,4-dinitrophenylhydrazone (1a) and the (Z)-phenylhydrazone (1b) of 5-amino-3-benzoyl-1,2,4- oxadiazole. The former rearranges into the relevant triazole 2a only at pS+ > 4.5 while undergoing hydrolysis at high proton concentration (pS+ < 3.5); on the contrary, the latter rearranges into 2b in the whole pS+ range examined (0.1 e pS+ e 14.9). Thus, for a deeper understanding of these differences we have now collected kinetic data on the rearrangement in dioxane/water of a series of 3- or 4-substituted (Z)-phenylhydrazones (1c-l) of 5-amino-3-benzoyl-1,2,4-oxadiazole in a wide ra…
Stereoselective synthesis and application of tridentate aminodiols derived from (+)-pulegone
2016
Abstract A library of tridentate aminodiols, derived from naturally occurring (R)-(+)-pulegone, was synthesized and applied as chiral catalysts in the addition of diethylzinc to benzaldehyde. The reduction of pulegone furnished pulegol, which was transformed into allylic trichloroacetamide via Overman rearrangement of the corresponding trichloroacetimidate. The protected enamine was subjected to dihydroxylation with OsO4/NMO system resulting in a 1:1 mixture of (1R,2R,4R)- and (1S,2S,4R)-aminodiol diastereomers. After the removal of the trichloroacetyl protecting groups, the obtained primary aminodiols were transformed into secondary ones. The regioselectivity of the ring closure of the N-b…
Phylogenomics of species from four genera of New World monkeys by flow sorting and reciprocal chromosome painting
2007
Abstract Background The taxonomic and phylogenetic relationships of New World monkeys (Platyrrhini) are difficult to distinguish on the basis of morphology and because diagnostic fossils are rare. Recently, molecular data have led to a radical revision of the traditional taxonomy and phylogeny of these primates. Here we examine new hypotheses of platyrrhine evolutionary relationships by reciprocal chromosome painting after chromosome flow sorting of species belonging to four genera of platyrrhines included in the Cebidae family: Callithrix argentata (silvered-marmoset), Cebuella pygmaea (pygmy marmoset), Callimico goeldii (Goeldi's marmoset) and Saimiri sciureus (squirrel monkey). This is t…
Skin involvement as the first manifestation of breast implant-associated anaplastic large cell lymphoma
2016
Breast implant-associated anaplastic large cell lymphoma (ALCL) is a newly described clinical and pathologic entity that typically presents as seroma in the fibrous scar around the implant. Less frequently, it presents as a solid peri-implant mass, and there have been no reports to date of cutaneous lesions as the presenting manifestation. We report the case of a 56-year-old woman with a history of bilateral breast reconstruction following breast cancer of the right breast who consulted with several papules on the right breast suggestive of metastasis. Histopathology showed a proliferation of large epithelioid lymphocytes with highly pleomorphic cells and nuclei. The neoplastic cells were C…
Endometrial stromal sarcomas: immunohistochemical, electron microscopical and cytogenetic findings in two cases.
1999
Uterine sarcomas are approximately 3% of all malignant uterine corpus tumours. Of these, the tumours that originate solely in the stromal elements of the uterine wall are infrequent and have not been well characterized cytogenetically. We report two cases of endometrial stromal sarcomas (ESS), one low grade and one high grade, diagnosed by conventional histology, immunocytochemistry, electron microscopy and cytogenetics. Morphologically clear-cut differential structures were seen at optical, immunohistochemical, and electron microscopic levels, permitting a clear differential diagnosis. The low-grade ESS expressed hormonal receptors and vimentin, whereas the high-grade ESS showed no hormone…
Semisynthesis of the Antiviral Abietane Diterpenoid Jiadifenoic Acid C from Callitrisic Acid (4-Epidehydroabietic Acid) Isolated from Sandarac Resin
2014
The semisynthesis of the antiviral abietane diterpenoid (+)-jiadifenoic acid C starting from the available methyl ester of callitrisic acid (4-epidehydroabietic acid) isolated from sandarac resin is reported. A protocol for the isolation of methyl callitrisate (methyl 4-epidehydroabietate) in gram quantities from sandarac resin is also described. Allylic C-17 oxygenation was introduced by regioselective dehydrogenation of the isopropyl group of methyl callitrisate with DDQ followed by selenium-catalyzed allylic oxidation. Ester hydrolysis afforded (+)-jiadifenoic acid C in 22% overall yield from methyl callitrisate. This semisynthetic route provides a convenient source of this anti-Coxsacki…
Fluorinated Heterocyclic Compounds. A Photochemical Approach to a Synthesis of Polyfluoroaryl-1,2,4-triazoles.
2005
The reaction of some fluorinated 1,2,4-oxadiazoles in the presence of methylamine or propylamine has been investigated. The irradiation in methanol or acetonitrile leads with acceptable yields to the corresponding fluorinated 1- methyl- or 1-propyl-1,2,4-triazole.
Fluorinated Heterocyclic Compounds. A Photochemical Approach to a Synthesis of Fluorinated Quinazolin-4-ones
2004
An efficient and generalized photochemical methodology for the preparation of fluorinated quinazolin-4-ones is described. Depending on the starting substrate, quinazolin-4-ones bearing a perfluoroalkyl- or perfluoroaryl- substituent in position 2 or fluorine atoms on any positions of the benzo-fused moiety can easily be obtained. 5-Aryl-3-perfluoroalkylpentafluorophenyl- or 5-polyfluoroaryl-3-phenyl(methyl)-1,2,4-oxadiazoles, respectively, can be considered as ideal precursors that can be transformed into the target quinazolin-4-ones by irradiation in the presence of triethylamine (TEA) (at λ = 313 nm) or pyrene (at λ = 365 nm) in dry methanol or acetonitrile as solvent. Some mechanistic co…
Stereoselective Synthesis of trans-4,5-Disubstituted Oxazolidin-2-ones by Intramolecular Conjugate Addition of N-p-Toluenesulfonyl Carbamates.
2003
p-Toluenesulfonyl carbamates (2a-d) were prepared starting from allylic alcohols (3), in which the double bond is conjugated with an electron withdrawing group. In the presence of a catalytic amount of DBU, an intramolecular cyclisation occurred, leading to trans-4,5-disubstituted oxazolidin-2-ones (1a-d) with total stereoselection, which can be precursors of syn-4-hydroxy-3-amino acids.