Collect. Czech. Chem. Commun. 1989, 54, 1311-1317

Kinetics of esterification of monoisopropylphenols with phosphoryl trichloride

Miroslav Maguraa, Ján Vojtkob and Ján Ilavskýb

a Chemko, 072 22 Strážske
b Department of Organic Technology, Slovak Technical University, 812 37 Bratislava


The kinetics of liquid-phase isothermal esterification of POCl3 with 2-isopropylphenol and 4-isopropylphenol have been studied within the temperature intervals of 110 to 130 and 90 to 110 °C, respectively. The rate constants and activation energies of the individual steps of this three-step reaction have been calculated from the values measured. The reaction rates of the two isomers markedly differ: at 110 °C 4-isopropylphenol reacts faster by the factors of about 7 and 20 for k1 and k3, respectively. This finding can be utilized in preparation of mixed triaryl phosphates, since the alkylation mixture after reaction of phenol with propene contains an excess of 2-isopropylphenol over 4-isopropylphenol.