Structure–reactivity correlation for the kinetics of the formation reaction of 4-(substituted phenyl)-1,4-dihydropyridines

• Published in: Journal of the Serbian Chemical Society Vol. 78; no. 12; p. 1963
• Main Authors: Urošević, Jovica V, Drmanić, Saša Ž, Nikolić, Jasmina B, Juranić, Ivan O, Jovanović, Bratislav Ž
• Format: Journal Article
• Language: English
• Published: Belgrade Journal of the Serbian Chemical Society 01.01.2013
• Subjects: Chemical synthesis; Constants; Correlation; Reaction kinetics; Reactivity; Regression analysis; Spectrophotometry
• DOI: 10.2298/JSC131120139U
• ISSN: 0352-5139

Quantitative structure–reactivity correlations for the kinetics of the Hantzsch synthesis of 4-(substituted phenyl)-1,4-dihydropyridines in the reaction between ethyl m- and p-substituted 2-benzylideneacetoacetate and the enAMine (ethyl 3-AMinocrotonate) was studied. The reaction kinetics was followed spectrophotometrically. It was found that the reaction correspond to second-order kinetics. Quantitative structure–reactivity correlations of log k were obtained with the corresponding substituent constants (s, s+, sI and ) using the HAMmett and extended HAMmett equation (dual substituent parAMeter, DSP, equation). They showed linear relationships with positive values of reaction constants (r). The obtained data were processed by linear regression analysis. It was confirmed that Michael addition of the enAMine to benzylidene represented the slow step of the reaction with a high positive charge at the benzylidene molecule. MO calculations were performed and they were in agreement with the conclusions derived from the structure–reactivity correlations.