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    Adsorption of indole and 2-methylindole on ligand-exchange matrix
    (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2004) Erciyes, N; Gurten, AA; Abdullah, MI; Ayar, A
    The adsorption of indole and its 2-methyl derivative from aqueous solutions onto cobalt(II)-carboxylated diaminoethane sporopollenin (CDAE-sporopollenin) was studied using a fixed-bed column at 25 +/- 0.1 degreesC. Minicolumn adsorption studies showed that the breakthrough and the total adsorption capacities of CDAE-sporopollenin in the concentration range we have studied increased with increasing external ligand concentration. The characteristics of the adsorption process were investigated using Scatchard plot analysis, where the equilibrium binding data for indole on ligand exchanger gave rise to a linear plot. However, for 2-methylindole, divergence from the Scatchard plot was evident, consistent with the participation of secondary equilibrium effects in the adsorption process. The adsorption behaviors of ligands on CDAE-sporopollenin were expressed by both the Langmuir and Freundlich isotherms. The adsorption isotherm data for these ligands on the resin can be satisfactorily fitted to the Freundlich isotherm within the concentration range studied. However, in the case of 2-methylindole, the experimental data did not fit the Langmuir model, especially when a high ligand concentration range is used; this is probably due to the nonspecific interactions between the ligand exchange matrix and the methyl group present. Ligand adsorption constants and correlation coefficients for the ligands were calculated from the Langmuir and Freundlich isotherms. (C) 2004 Elsevier Inc. All rights reserved.
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    Electrophilic substitution in indoles, part 20' Hammett correlations of the coupling of aryldiazonium tetrafluoroborates with indole and its 1-, 2-and 3-methyl derivatives
    (Pergamon-Elsevier Science Ltd, 2003) Aldemir, S; Kahyaoglu, H; Abdullah, MI
    Hammett plots for the coupling of a range of substituted aryldiazonium tetrafluoroborate salts in dry acetonitrile with indole and its 1-, 2- and 3-methyl derivatives gave linear relationships, with rho values ca. of +2.60, +2.54, +2.40 and +3.60 respectively.
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    First synthesis of 2-[alkylamino(diethoxyphosphoryl)methyl] acrylic ethyl esters
    (Pergamon-Elsevier Science Ltd, 2003) Kraiem, H; Abdullah, MI; Amri, H
    The ethyl alpha-bromomethyl-beta-(diethoxyphosphoryl)acrylic acid ester 9 has been prepared by addition of bromine to allylphosphonate 7 then dehydrobromination with DBU in acetonitrile. Reaction of allylic bromide 9 with primary amines in a bimolecular S(N)2'-type mechanism in methanol at low temperature, gives rise to the 2-[alkylamino(diethoxyphosphoryl)methyl]acrylic acid ethyl esters 6. (C) 2002 Elsevier Science Ltd. All rights reserved.