52897-99-1Relevant academic research and scientific papers
Nucleofugality and nucleophilicity of fluoride in protic solvents
Nolte, Christoph,Ammer, Johannes,Mayr, Herbert
, p. 3325 - 3335 (2012/06/17)
A series of p-substituted benzhydryl fluorides (diarylfluoromethanes) were prepared and subjected to solvolysis reactions, which were followed conductometrically. The observed first-order rate constants k1(25 °C) were found to follow the correlation equation log k1(25 °C) = sf(Nf + Ef), which allowed us to determine the nucleofuge-specific parameters Nf and sf for fluoride in different aqueous and alcoholic solvents. The rates of the reverse reactions were measured by generating benzhydrylium ions (diarylcarbenium ions) laser flash photolytically in various alcoholic and aqueous solvents in the presence of fluoride ions and monitoring the rate of consumption of the benzhydrylium ions by UV-vis spectroscopy. The resulting second-order rate constants k-1(20 °C) were substituted into the correlation equation log k-1 = sN(N + E) to derive the nucleophilicity parameters N and sN for fluoride in various protic solvents. Complete Gibbs energy profiles for the solvolysis reactions of benzhydryl fluorides are constructed.
Anti-inflammatory effects of two new methyl and morpholine derivatives of diphenhydramine on rats
Ahmadi, Abbas,Khalili, Mohsen,Hajikhani, Ramin,Safari, Narjes,Nahri-Niknafs, Babak
, p. 3532 - 3540 (2013/02/25)
Diphenhydramines are one of the first-generation histamine H1-receptor antagonists of the ethanolamine class that demonstrate many pharmacological properties including anti-inflammatory effects. In this research, bromo (II) and two new tolyl derivatives of I, (Di [p-tolyl] [dimethylaminoethoxy] methane, III) and (Di [p-tolyl] [2-morpholinoethoxy] methane, IV) were synthesized. Their acute and chronic anti-inflammatory activities were evaluated with the formalin and histamine-induced rat paw edema. The vascular permeability in formalin and histamine-induced paw edema, in xylene-induced ear edema, and in peritonitis after acetic acid application into peritoneal cavity were also measured and compared to II. Cotton pellet-induced granuloma model was selected for inducing chronic inflammations in rats. The newly synthesized analogs of diphenhydramine seemed effective to decrease acute inflammations. It was concluded that the prominent anti-phlogistic effects of the new drugs could be related to its reduction vascular permeability mechanism(s) or to its antagonistic effects on H1 histamine receptors. Springer Science+Business Media, LLC 2011.
N-heterocyclic carbene-catalyzed cross-coupling of aromatic aldehydes with activated alkyl halides
Padmanaban, Mohan,Biju, Akkattu T.,Glorius, Frank
supporting information; experimental part, p. 98 - 101 (2011/03/19)
N-Heterocyclic carbene-catalyzed umpolung of aldehydes followed by their interception with diarylbromomethanes has been reported. This conceptually novel transition-metal-free cross-coupling of aldehydes with alkyl halides works well at low catalyst loadings and under mild reaction conditions leading to the formation of diaryl acetophenone derivatives in good yields. In addition, α-halo ketones and esters can also be used as aldehyde reaction partners.
Synthesis and anticonvulsant activity of some cinnamylpiperazine derivatives
Hu, Chuan,Sun, Zhi-Gang,Wei, Cheng-Xi,Quan, Zhe-Shan
, p. 661 - 664 (2011/11/29)
A series of cinnamylpiperazine derivatives was synthesized using different benzophenone as starting material. The structures of the compounds were proved by their IR, 1H-NMR spectroscopic data and mass spectra data. The anticonvulsant activities of these compounds were evaluated with maximal electroshock (MES) test and rotarod test with intraperitoneal injection on KunMing mice. Among all the flunarizine analogues, no one exhibited better anticonvulsant activity than flunarizine. Flunarizine (4i) exhibited anticonvulsant activity with ED50 of 38.1 mg/kg, TD50 of 164.3 mg/kg and PI of 4.3 through administration intraperitoneal, and with ED50 of 56.8 mg/kg, TD50 of 456.3 mg/kg and PI of 8.0 through oral administration.
Target directed chemotherapy of tumours of the sexual organs
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, (2008/06/13)
The invention relates to dialkyltriazene-bearing estrogens and anti-estrogens that are suited for use as chemotherapeutic drugs for treating carcinomas of the sexual organs of humans and animals.
Kinetics of the solvolyses of benzhydryl derivatives: Basis for the construction of a comprehensive nucleofugality scale
Denegri, Bernard,Streiter, Andre,Juric, Sandra,Ofial, Armin R.,Kronja, Olga,Mayr, Herbert
, p. 1648 - 1656 (2007/10/03)
A series of 21 benzhydrylium ions (diarylmethylium ions) are proposed as reference electrofuges for the development of a general nucleofugality scale, where nucleofugality refers to a combination of leaving group and solvent. A total of 167 solvolysis rate constants of benzhydrylium tosylates, bromides, chlorides, trifluoroacetates, 3,5-dinitrobenzoates, and 4-nitroben-zoates, two-thirds of which have been determined during this work, were subjected to a least-squares fit according to the correlation equation log k 25°C = Sf(Nf + Ef), where s f and Nf are nucleofuge-specific parameters and E f is an electrofuge-specific parameter. Although nucleofuges and electrofuges characterized in this way cover more than 12 orders of magnitude, a single set of the parameters, namely sf, Nf, and E f, is sufficient to calculate the solvolysis rate constants at 25°C with an accuracy of ± 16%. Because sf ≈ 1 for all nucleofuges, that is, leaving group/ solvent combinations, studied so far, qualitative discussions of nucleofugality can be based on Nf.
Kinetics of the reactions of halide anions with carbocations: Quantitative energy profiles for SN1 reactions
Minegishi, Shinya,Loos, Robert,Kobayashi, Shinjiro,Mayr, Herbert
, p. 2641 - 2649 (2007/10/03)
Rate constants for the reactions of Laser flash photolytically generated benzhydrylium ions (diarylcarbenium ions) with halide ions have been determined in various solvents, including neat and aqueous acetonitrile as well as some alcohols. Substitution of the rate constants into the correlation equation log k = s(N + E) yields the nucleophilicity parameters N for the halide ions in different solvents. Linear correlations with negative slopes are found between the nucleophilicity parameters N for Cl- and Br- in different solvents and the solvent ionizing powers Y of the corresponding solvents. Increasing halide solvation reduces the rates of carbocation/chloride combinations by approximately half as much as it increases the rates of ionizations of benzhydryl chlorides. Comparison of the solvent dependent nucleophilicity parameters N of halide anions and the nucleophilicity parameters N1 for solvents yields a quantitative prediction of common ion rate depression, as demonstrated by the analysis of a variety of literature reported mass-law constants α. Combination of the rate constants for the reactions of benzhydrylium ions with halide ions (k-1) reported in this work with the ionization constants of benzhydryl halides (k1) and the recently reported rate constants for the reactions of benzhydrylium ions with solvents (k2) yields complete quantitative free energy profiles for solvolysis reactions. The applicability of Hammond's postulate for interpreting solvolysis reactions can thus be examined quantitatively.
