Condensation of p-Dimethylaminocinnamaldehyde with Aniline and Substituted Anilines in Micellar Media

Abstract

Optimal conditions were found for the reactions of aniline and its hydroxy-, carboxy-, methyl-, and nitro-substituted derivatives with p-dimethylaminocinnamaldehyde in the presence of sodium dodecyl sulfate micelles in the pH range 136. A correlation was revealed between the optimal pH value pK a of aromatic amines. The reaction in the model system aniline3p-dimethylaminocinnamaldehyde3sodium dodecyl sulfate in micelles formed by anionic surfactants is accelerated more than 1000-fold due to increased concentration of the reactive species in sodium dodecyl sulfate micelles.

Sequential injection analysis system with spectrophotometric detection for determination of norfloxacin and ciprofloxacin in pharmaceutical formulations

“…The probable mechanism for this reaction is shown in the Scheme 1, which is to large extent based on reactions suggested in the literature. [27][28][29] These studies also confirmed the effect of SDS micelles in the condensation of p-DAC with aromatic amines [30][31][32] and revealed the dependence of the reaction on temperature. Micelles can increase the molar absorptivity of the chromophore, modify equilibrium constants and reaction yields, shift spectral bands, co-solubilize samples, reagents and products, and catalyze reactions.…”

“…30 In addition, the surfactants can also be useful in softening the experimental conditions required to carry out the reaction, such as: reducing the temperature or acid and reagent concentrations. 30,31 This is of interest for simplification of manual and automated analytical procedures, and will contribute to green chemistry, 32 due to its capability of decreasing the reagent consumption and as a consequence, minimizing effluent generation.…”

Analytical Aspects of Reactions of Primary Aromatic Amines with p-Dimethylaminocinnamic Aldehyde in the Presence of Surfactant Ions and Micelles

“…Because both forms are reactive, the overall rate of aniline condensation with p-dimethylaminocinnamic aldehyde increases, so that the yield of the analytical form increases as well (an increase in the absorbance) [11]. The regularities found can be extended to the condensation of other primary aromatic amines with pdimethylaminocinnamic aldehyde in anionic surfactant micelles.…”

Determination of ambroxol in syrups using diffuse reflectance spectroscopy

“…29 The effect of surfactant micelles in the condensation of aldehydes, such as p-DAC, with amines has been subject of a number of publications. [30][31][32] Preliminary experiments revealed a significant enhancement of magnitude in the sensitivity of the reaction in the presence of SDS and no shift in the absorption maximum takes place. In the sequence, was evaluated the stability of colored product and observed that the reflectance measurement remained stable at least 24 h at room temperature (25 ºC).…”