15971-29-6Relevant articles and documents
4-Hydroxy-1-naphthaldehydes: Proton transfer or deprotonation
Manolova,Kurteva,Antonov,Marciniak,Lochbrunner,Crochet,Fromm,Kamounah,Hansen
, p. 10238 - 10249 (2015)
A series of naphthaldehydes, including a Mannich base, have been investigated by UV-Vis spectroscopy, NMR and theoretical methods to explore their potential tautomerism. In the case of 4-hydroxy-1-naphthaldehyde concentration dependent deprotonation has been detected in methanol and acetonitrile. For 4-hydroxy-3-(piperidin-1-ylmethyl)-1-naphthaldehyde (a Mannich base) an intramolecular proton transfer involving the OH group and the piperidine nitrogen occurs. In acetonitrile the equilibrium is predominantly at the OH-form, whereas in methanol the proton transferred tautomer is the preferred form. In chloroform and toluene, the OH form is completely dominant. Both 4-hydroxy-1-naphthaldehyde and 4-methoxy-1-naphthaldehyde (fixed enol form) show dimerization in the investigated solvents and the crystallographic data, obtained for the latter, confirm the existence of a cyclic dimer.
Convenient synthesis of 2-allyl-3-bromo-1,4-dimethoxynaphthalene: Key intermediate as building block for bioactive pyranonaphthoquinones
Limaye, Rohan A.,Gaur, Pinki,Paradkar, Madhusudan V.,Natu, Arun D.
, p. 313 - 319 (2012)
Synthesis of a key precursor 2-allyl-3-bromo-1,4-dimethoxynaphthalene (1) used in constructing various naturally occurring biologically active pyranonaphthoquinones is carried out utilizing easily available 1-methoxynaphthalene as a starting material. The synthesis was accomplished with Dakin's oxidation and Claisen rearrangement, thereby providing another easy approach toward (1) without involving highly lachrymatric 2-bromonaphthoquinone. Copyright Taylor & Francis Group, LLC.
Reductive Coupling between C-N and C-O Electrophiles
He, Rong-De,Li, Chun-Ling,Pan, Qiu-Quan,Guo, Peng,Liu, Xue-Yuan,Shu, Xing-Zhong
supporting information, p. 12481 - 12486 (2019/09/04)
The cross-electrophile reaction is a promising strategy for C-C bond formation. Recent studies have focused mainly on reactions with organic halides. Here we report a coupling reaction between C-N and C-O electrophiles that demonstrates the possibility of constructing a C-C bond via C-N and C-O cleavage. Several reactions between benzyl/aryl ammonium salts and vinyl/aryl C-O electrophiles have been studied. Preliminary mechanistic studies revealed that the benzyl ammoniums were activated through a radical mechanism.
Arylthiosemicarbazones as antileishmanial agents
Manzano, José Ignacio,Cochet, Florent,Boucherle, Benjamin,Gómez-Pérez, Verónica,Boumendjel, Ahcène,Gamarro, Francisco,Peuchmaur, Marine
, p. 161 - 170 (2016/08/02)
Based on a screening process, we targeted substituted thiosemicarbazone as potential antileishmanial agents. Our objective was to identify the key structural elements contributing to the anti-parasite activity that might be used for development of effective drugs. A series of 32 compounds was synthesized and their efficacy was evaluated against the clinically relevant intracellular amastigotes of Leishmania donovani. From these, 22 compounds showed EC50values below 10?μM with the most active derivative (compound 14) showing an EC50of 0.8?μM with very low toxicity on two different mammalian cell lines. The most relevant structural elements required for higher activity indicate that the presence of a fused bicyclic aromatic ring such as a naphthalene bearing an alkyl or an alkoxy group substituent are prerequisites. Owing to the easy synthesis, high activity and low toxicity, the most active compounds could be considered as a lead for further development.