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  • Theoretical, Physical and Computational Chemistry  (3)
  • 2-amino-5-chlorobenzophenone  (1)
  • 1
    ISSN: 0894-3230
    Keywords: phenyllithium ; E-cinnamaldehyde ; organolithium ; addition ; mechanism ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The reaction of phenyllithium (PhLi) with E-cinnamaldehyde (1) has been fully examined. Besides the main product E-1,3-diphenyl-2-propen-1-ol (2), three other by-products were detected: E-cinnamyl alcohol (3), E-chalcone (4) and E-1,3-diphenylpropanone (5). The effect of several variables on the nature and relative yields of products was examined. In all the solvents studied, the selectivity of the reaction was higher at higher temperatures, probably owing to aggregation effects; at lower temperatures the reaction is slower and the amount of by-products increases. The addition is complete in 1 h at 0 °C in THF for a [PhLi]:[1] ratio of 1:1, and longer reaction times have almost no effect, while for the reaction in toluene the amount of by-products increases when the reaction mixture is allowed to stand. The concentration of the reagents has no important effect on the reaction as long as the ratio is kept equal to 1:1. The influence of light was examined and a marked decrease in the selectivity of the reaction was observed. When the reaction was carried out in the presence of radical traps, no by-products were detected. Finally, for a [PhLi]:[1] ratio of 3:1 the main product is the dihydrochalcone 5, especially for long reaction times. All the above results could be interpreted in a reaction scheme involving electron transfer from PhLi to 1, and further reaction of the radical ions formed as well as reaction of dimeric PhLi without previous deaggregation when the ratio is 3:1.­© 1998 John Wiley & Sons, Ltd.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 10 (1997), S. 97-106 
    ISSN: 0894-3230
    Keywords: 2-amino-5-chlorobenzophenone ; hydrochloric acid ; kinetics ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: ---The reaction of 2-amino-5-chlorobenzophenone (1) with 0·5-2 M HCl was studied in 1:1 (v/v) MeOH-H2O at 60 and 80 °C. Products that were isolated were characterized as 2-(N-methylamino-5-chlorobenzophenone) (2), 2- amino-3,5-dichlorobenzophenone (3), 2-N-methylamino-3,5-dichlorobenzophenone (4), 2-(N,N)-dimethylamino-5- chlorobenzophenone (5), 2,4-dichloro-10-methyl-9,10-acridinone (6) and 2,4-dichloro-9,10-acridinone (7). The rates of reaction of 1 and the rates of formation of 2-5 were measured at several HCl concentrations. The methyl transfers, the chlorination and the cyclization reactions that give rise to 2-7 were unexpected under the present reaction conditions. A set of differential equations was proposed in order to calculate the rate constants for each step of this complex reaction. The proposed reaction scheme also takes into account the reaction 2→1 and permits the calculation of the rate constants for this reversible reaction. The experimental values of the rate constants for reaction of 1 were compared with those for 2 under the same reaction conditions, in order to evaluate the importance of the methyl group on the methyl transfer reactions; it was found that the methyl group is not required for the unexpected reaction to occur. © 1997 by John Wiley & Sons, Ltd.
    Additional Material: 6 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 10 (1997), S. 233-241 
    ISSN: 0894-3230
    Keywords: surface effects ; radical anions ; benzoyl radical ; coupling of radicals ; surface catalysis ; electron transfer ; reactions in the double laye ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Benzaldehyde in THF reacts with lithium metal to give the expected reduction product, benzyl alcohol, plus benzoin and benzyl as minor products. The kinetics of the overall reaction as well as the partial rate coefficients of the several steps have been determined under various reaction conditions. It was found that adsorption on the surface and electron transfer from the lithium to benzaldehyde are the slow steps. The experimental results show interesting surface effects, and evidence for significant radical intermediates, which were characterized by their epr spectra and trapping experiments, results useful to gain insight into the mechanisms of these and other related reactions. © 1997 John Wiley & Sons, Ltd.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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