Study of the reaction between dimethyl phenols and formaldehyde in alkaline medium

Abstract

The reaction of several dimethyl phenols with formaldehyde in alkaline medium was investigated. The addition products were separated by means of high pressure liquid chromatography and identified using IR and NMR spectroscopy. 2,3dimethyl phenol yields four, 2,4dirnethyl phenol one, 2,s-dimethyl phenol four, 2,6-dimethyl phenol one, 3,4-dimethyl phenol three, and 3,Sdimethyl phenol five addition products. 3.5-dimethyl phenol was the most reactive, 2,6-dimethyl and 2.4-dimethyl phenols the least reactive species. Rate constants for individual reactions were obtained from the dependence of concentrations on the reaction time. ZUSAM MENFASSUNG:Eine Reihe von Reaktionen zwischen den Dimethylphenolen und Formaldehyd im alkalischen Bereich wurden untersucht. Die Additionsprodukte wurden mittels Hochdruckfliissigkeitschromatographie getrennt und mittels IRund NMR-Spektroskopie identifiziert. 2.3-Dimethylphenol gibt vier, 2.4-Dimethylphenol ein, 2,5-Dimethylphenol vier, 2.6-Dimethylphenol ein, 3,CDimethylphenol drei und 3,5-Dimethylphenol fiinf Additionsprodukte. 3,s-Dimethylphenol ist am reaktivsten, 2,4-und 2,6-Dimethylphenol sind am wenigsten reaktiv. Die Geschwindigkeitskonstanten wurden aus der Abhangigkeit der Konzentration der Reaktionsprodukte von der Reaktionszeit ermittelt.

Predicting the reactivity of phenolic compounds with formaldehyde under basic conditions: Anab initio study

“…There is a large amount of literature on the general reactivity of aromatic compounds, especially correlation of reactivity with Hammett activity coefficients,5 localization energy,6 and frontier molecular orbitals 7. Many experimental kinetic studies have been conducted on the reactivity of phenolic compounds (especially phenol) with formaldehyde,8–20 but few systematic studies have been conducted that compare the reactivity of different phenolic compounds with formaldehyde, especially under the same reaction conditions.…”