- Dynamic Behavior of Photoexcited Solutions of 4-Nitroveratrole Containing OH(1-) or Amines
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Kinetics and mechanism of the photoinduced reactions of 4-nitroveratrole (NV) with OH(1-) and a number of aliphatic amines have been studied by laser kinetic spectroscopy and by measurement of transient changes in electrical conductivity.In the case of OH(1-) only reactions with NV in its lowest triplet state (T0) are observed and these lead to substitution of the OCH3 group at atom C(2) of the aromatic molecule and to formation of a number of transient ?-complexes, which return to NV.In the case of the amines both excited singlet state and triplet state reactionsare observed.The singlet state reactions with methylamine and with n-hexylamine lead to substitution of the OCH3 group at atom C(2).Although piperidine quenches the excited singlet states involved, this does not lead to substitution at C(2).The triplet state reactions with the amines start with a discrete electron-transfer reaction in which the radical anion (E) of NV is formed.Subsequent reaction of E with the radical cation of the amine leads to substitution at C(1) and to a number of ?-complexes, which return to NV.
- Eijk, Alexander M. J. van,Huizer, A. Herbert,Varma, Cyril A. G. O.,Marquet, Jorge
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- N-(3,4-disubstituted phenyl) salicylamide derivatives
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A compound represented by the following formula (I) or a salt thereof: wherein R1, R2, R3 and R4 represent hydrogen atom, a halogen atom, cyano group, nitro group, a C1-4 alkyl group, a halogenated C
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Page/Page column 38
(2008/12/07)
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- DIARYL UREA DERIVATIVES USEFUL FOR THE TREATMENT OF PROTEIN KINASE DEPENDENT DISEASES
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The invention relates to the use of diaryl urea derivatives in the treatment of protein kinase dependent diseases or for the manufacture of pharmaceutical compositions for use in the treatment of said diseases, methods of use of diaryl urea derivatives in the treatment of said diseases, pharmaceutical preparations comprising diaryl urea derivatives for the treatment of said diseases, diaryl urea derivatives for use in the treatment of said diseases, novel diaryl urea derivatives, pharmaceutical preparations comprising these novel diaryl urea derivatives, processes for the manufacture of the novel diaryl urea derivatives, the use or methods of use of the novel diaryl urea derivatives as mentioned above, and/or these novel diaryl urea derivatives for use in the treatment of the animal or human body.
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- Photosubstitution-photoreduction mechanistic duality in the SET photoreactions of nitrophenyl ethers with amines. The role of the steps that follow the ET
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Nitrophenyl ethers are photoreduced by primary amines in water through a mechanism initiated by single electron transfer that is in direct competition with the single electron transfer photosubstitution mechanism (S(N)Ar*-SET). Our results indicate that the preferred pathway does not depend on the electron donor or proton donor ability of the amine. The key factor that determines the progress of the photoreaction is the structure of the carbon skeleton of the amine, particularly the type of hydrogens on the carbon α to the amino group. A mechanistic rationale that includes hydrogen atom transfer as a key step is discussed.
- Mir, Miquel,Marquet, Jordi,Massot, Oriol
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p. 12603 - 12614
(2007/10/03)
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- ON THE REGIOSELECTIVITY OF THE NUCLEOPHILIC AROMATIC PHOTOSUBSTITUTIONS OF 4-NITROVERATROLE. A THREEFOLD MECHANISTIC PATHWAY.
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4-Nitroveratrole (NVT) is photosubstituted with primary amines, piperidine and hydroxide ion.Primary amines and hydroxide ion cause replacement of the methoxy group in meta position with respect to the nitro group whereas piperidine photosubstitutes the methoxy group in para to the nitro group.Photoreactions with piperidine and hydroxide ion involve attack of the amine upon a triplet excited state of NVT.Mechanistic evidences indicate that the reaction with hydroxide ion is probably a SN23Ar* process whereas the reaction with piperidine involves a radical ion pair formed via electron transfer from the amine to a triplet excited state.Photoreactions with primary amines involve attack of the amine upon a singlet excited state of NVT (SN21 Ar* process).These results are discussed and justified in the context of nucleophile ionization potential considerations and ground state donor-acceptor complex formation abilities.
- Cantos, Albert,Marquet, Jorge,Moreno-Manas, Marcial,Castello, Assumpta
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p. 2607 - 2618
(2007/10/02)
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