21992-33-6Relevant academic research and scientific papers
Regioselective alkylation of anthrone, 5,5-dimethyl-3-isoxazolidinone and 4-methylquinolone by phase transfer catalysis
Dehmlow, Eckehard Volker,Bollhoefer, Joerg,Thye, Gorden
, p. 113 - 115 (2007/10/03)
Anthrone (1) can be alkylated selectively to give O-, C,O- or C,C-substituted compounds 2, 4, or 5, respectively. Similarly, 5,5-dimethyl-3-isoxazolidinone (6) and 4-methylquinolone (9) yield N- or O-derivatives 7 and 8 or 10 and 11, respectively. The product ratios can be influenced strongly sometimes by use of different phase transfer catalysts, but the sensitivity of each reaction towards the catalysts is unique.
Thermolabile Hydrocarbons, 34. - Thermal Stability of 9,9'-Bixanthene and 9,9',10,10'-Tetrahydro-10,10,10',10'-tetramethyl-9,9'-bianthracene. - Stabilisation Energies of Planar Benzhydryl Radicals
Herberg, Clemens,Beckhaus, Hans-Dieter,Ruechardt, Christoph
, p. 2065 - 2072 (2007/10/02)
The thermal cleavage of the central CC bonds in the title compounds was investigated.The activation parameters were obtained from kinetics and the equilibrium enthalpies and entropies from the temperature dependence of the equilibrium radical concentrations, determined by quantitative ESR. ΔH(excit.) and ΔHDiss are nearly identical but not ΔS(excit.) and ΔSDiss, as expected.The radical stabilisation enthalpies RSE obtained from these data (RSE: 7a = 17.9+/-1.3; 7b = 15.6+/-1.4 kcal/mol) correspond closely to twice the RSE of α-phenylethyl radicals (8.0+/-1.5 kcal/mol) determined previously.The smaller RSE of the benzhydryl radical (12.9+/-0.9 kcal/mol), therefore, must be due to its nonplanarity. - Key Words: C-C Bond cleavage, energetics and kinetics of / Radicals, stability of / ESR
TELE-SUBSTITUTIONS EN SERIE ANTHRACENIQUE-I. COMPORTEMENT DU BROMO-9-METHYL-10 ANTHRACENE VIS-A-VIS DES ANIONS PHENATES ET ALCOOLATES
Rigaudy, J.,Seuleiman, A.M.,Cuong, Nguyen Kim
, p. 3143 - 3150 (2007/10/02)
Treatment of 9-bromo-10-methyl anthracene 1, in dipolar aprotic solvents, by alkaline phenoxide or alkoxides leads essentially to a mixture of the expected ether, 9-phenoxy (or alkoxy)-10-methyl anthracene 2, normal substitution product (NSP), and of the isomeric ether, 9-phenoxymethyl (or alkoxymethyl)-anthracene 3, tele-substitution product (TSP).It is shown that both ethers must derive from a common unstable intermediate, the 9-bromo-10-methylene-9,10-dihydroanthracene 8, coming from 1 by a prototropic shift and which can undergo both types of substitution.With more hindered phenoxide ions, only the tele-substitution process is observed.
