15N NMR and FTIR studies of 2,4-dinitroanilnes and their salts

Twenty-two 2,4-dinitroanilines were synthesised and their pK(a) values were determined. The 2,4-dinitroanilines and their protonated forms were studied by N-15 NMR spectroscopy. The relations between the N-15 NMR chemical shifts and the pK(a) values of the 2,4-dinitroanilines and their salts were found to be linear. The deprotonation reaction of N-methyl-2,4-dinitroanilines and N-methyl-2,4,6-trinitroaniline by MTBD was successful only for the latter and yielded protonated MTBD molecule and the anion in which the electrons are strongly delocalised. The kinetic parameters of the 2,4-dinitroanilines in reactions with hydroxide ions in mixed solvent DMSO:water (95:5, v/v) were determinated and discussed. (C) 2000 Elsevier Science B.V. All rights reserved.