21905-75-9Relevant academic research and scientific papers
Formal Aniline Synthesis from Phenols through Deoxygenative N-Centered Radical Substitution
Lardy, Samuel W.,Luong, Kristine C.,Schmidt, Valerie A.
supporting information, p. 15267 - 15271 (2019/12/11)
Phenolic, lignin-derived substrates have emerged as desirable biorenewable chemical feedstocks for coupling reactions. A radical-mediated conversion of phenol derivatives to anilines is reported, using unfunctionalized hydroxamic acids as the N-centered radical source. The applicability of this triethyl phosphite mediated O-atom transfer approach, which tolerates a range of steric and electronic demands to naturally occurring phenols and lignin models, has been demonstrated in this work to access the corresponding aniline derivatives.
Design, synthesis and cardiovascular evaluation of some aminoisopropanoloxy derivatives of xanthone
Kubacka,Szkaradek,Mogilski,Pańczyk,Siwek,Grybo?,Filipek,?mudzki,Marona,Waszkielewicz
, p. 3773 - 3784 (2018/05/04)
A series of aminoisopropanoloxy derivatives of xanthone has been synthesized and their pharmacological properties regarding the cardiovascular system has been evaluated. Radioligand binding and functional studies in isolated organs revealed that title compounds present high affinity and antagonistic potency for α1-(compound 2 and 8), β-(compounds 1, 3, 4, 7), α1/β-(compounds 5 and 6) adrenoceptors. Furthermore, compound 7, the structural analogue of verapamil, possesses calcium entry blocking activity. The title compounds showed hypotensive and antiarrhythmic properties due to their adrenoceptor blocking effect. Moreover, they did not affect QRS and QT intervals, and they did not have proarrhythmic potential at tested doses. In addition they exerted anti-aggregation effect. The results of this study suggest that new compounds with multidirectional activity in cardiovascular system might be found in the group of xanthone derivatives.
A photoredox-neutral Smiles rearrangement of 2-aryloxybenzoic acids
Gonzalez-Gomez, Jose C.,Ramirez, Nieves P.,Lana-Villarreal, Teresa,Bonete, Pedro
supporting information, p. 9680 - 9684 (2017/11/30)
We report on the use of visible light photoredox catalysis for the radical Smiles rearrangement of 2-aryloxybenzoic acids to obtain aryl salicylates. The method is free of noble metals and operationally simple and the reaction can be run under mild batch or flow conditions. Being a redox neutral process, no stoichiometric oxidants or reductants are needed.
Carboxyl radical-assisted 1,5-aryl migration through Smiles rearrangement
Hossian, Asik,Jana, Ranjan
, p. 9768 - 9779 (2016/10/31)
We report herein, a silver(i)-catalyzed Smiles rearrangement of 2-aryloxy- or 2-(arylthio)benzoic acids to provide aryl-2-hydroxybenzoate or aryl-2-mercaptobenzoate dimer, respectively, through 1,5-aryl migration from oxygen or sulfur to carboxylate oxygen. Mechanistically, the aryl ether moiety undergoes an intramolecular ipso attack by the carboxyl radical followed by a C-O or C-S bond cleavage. Aryl-2-mercaptobenzoates undergo oxidative dimerization through a thiol moiety in situ.
Cardiovascular activity of the chiral xanthone derivatives
Szkaradek, Natalia,Rapacz, Anna,Pytka, Karolina,Filipek, Barbara,Zelaszczyk, Dorota,Szafrański, Przemys?aw,S?oczyńska, Karolina,Marona, Henryk
, p. 6714 - 6724 (2015/10/19)
A series of 6 derivatives of xanthone were synthesized and evaluated for cardiovascular activity. The following pharmacological experiments were conducted: the binding affinity for adrenoceptors, the influence on the normal electrocardiogram, the effect on the arterial blood pressure, the effect on blood pressor response and prophylactic antiarrhythmic activity in adrenaline induced model of arrhythmia (rats, iv). Two compounds revealed nanomolar affinity for α1-adrenoceptor which was correlated with the strongest cardiovascular (antiarrhythmic and hypotensive) activity in animals' models. They were enantiomers of previously described (R,S)-4-(2-hydroxy-3-(4-(2-methoxyphenyl)piperazin-1-yl)propoxy)-9H-xanthen-9-one hydrochloride and revealed similar antiarrhythmic potential in adrenaline induced model of arrhythmia in rats after intravenous injection (ED50 = 0.53 mg/kg and 0.81 mg/kg, respectively). These values were lower than values obtained for reference drug urapidil. These compounds were more active in this experiment than urapidil (ED50 = 1.26 mg/kg). The compound 5 administered iv at doses of 0.62-2.5 mg/kg at the peak of arrhythmia prevented and/or reduced the number of premature ventricular beats in a statistically significant manner. The ED50 value was 1.20 mg/kg. The S-enantiomer (6) given at the same doses did not show therapeutic antiarrhythmic activity in this model. These compounds significantly decreased the systolic and diastolic blood pressure throughout the whole observation period in anesthetized, normotensive rats. The studied enantiomers showed higher toxicity than urapidil, but imperceptibly higher that another cardiovascular drugs, that is, carvedilol or propranolol. They were also evaluated for mutagenic potential in the Ames (Salmonella) test. It was found that at the concentrations tested the compounds were non mutagenic when compared to solvent control. Results were quite promising and suggested that in the group of xanthone derivatives new potential antiarrhythmics and hypotensives might be found.
Design, Synthesis and Potential Use of 3,9-Substituted Xanthene Handles for Solid Phase Peptide Synthesis
Somlai, Csaba,Nyerges, Levente,Penke, Botond,Hegyes, Peter,Voelter, Wolfgang
, p. 429 - 433 (2007/10/02)
Theoretical calculations on different xanthene derivatives and related structures were performed and as a result conclusions could be drawn for the acid-lability of substituted xanthenes. (9-Hydroxyxanthene-3-oxy)acetic- and valeric acid (6a and 6b) were selected, synthesized in a six-step route, and 6b was tested for its applicability as a handle for solid phase synthesis of peptides.
Design, Synthesis, and Pharmacological Evaluation of Potent Xanthone Dicarboxylic Acid Leukotriene B4 Receptor Antagonists
Jackson, William T.,Boyd, Robert J.,Froelich, Larry L.,Gapinski, D. Mark,Mallett, Barbara E.,Sawyer, J. Scott
, p. 1726 - 1734 (2007/10/02)
In an effort to develop increasingly potent and specific leukotriene B4(LTB4) receptor antagonists, several xanthone dicarboxylic acids were synthesized and evaluated.Two separate synthetic routes were used to construct a xanthone nucleus containing a regiospecific orientation of each carboxylic acid pharmacophore.These compounds represent the major conformationally-restricted analogues of benzophenone dicarboxylic acids previously shown to antagonize the activation of human neutrophils by LTB4.The most potent agent was compound 32, which inhibited the specific binding of LTB4 to receptors on intact human neutrophils (IC50, 6.2 +/- 0.1 nM), LTB4-induced luminol-dependent chemiluminescence (IC50, 55 +/- 11 nM), aggregation (IC50, 133 +/- 42 nM), and chemotaxis (IC50, 899 +/- 176 nM).The compound was a poor antagonist of N-formyl-L-methionyl-L-leucyl-L-phenylalanine-induced chemiluminescence (IC50, 1599 +/- 317 nM) and aggregation (IC50, 2166 +/- 432 nM), indicating specificity in the inhibition of LTB4-stimulated events.Compound 32(LY210073), which was completely devoid of agonist activity, appears to be one of the strongest inhibitors of LTB4 receptor binding reported so far.
