SYNTHESIS OF ALKYL-PHENYL ETHERS UNDER THE CONDITIONS OF INTERPHASE CATALYSIS

Abstract

The results of studies on the synthesis of alkyl phenyl ethers are presented. The interaction of phenol with alkyl halides under the phase transfer catalysis conditions lead to the alkyl-phenyl ethers which are of great practical interest. They are used in the manufacture of medicines, in the perfume industry, agriculture, ete. Such compounds occupy a special place among antioxidants as antiknock gasoline additives. Anisole is used as a solvent and as an intermediate product in the production of dyes, medicines and fragrances. The regularities and main factors determining the regioalkylation of phenol with alkyl halides have been established. The regioselectivity of the process depends on the structure of the alkyl halide, as well as on the type of catalyst system and the corresponding catalysts, on the ratio of the starting reagents.

The main method for the synthesis of alkyl-phenyl ether is the interaction of phenol with alkyl halides or alkyl sulfates in the presence of bases. Both reaction paths ( O- or C- alkylation) are characterized by very slight differences in the values of free energy. The selectivity of phenolate alkylation to the oxygen atom should be resolved to obtain alkyl phenyl ether.

Dimethylbenzylcetyl ammonium bromide is the best phase transfer catalyst for phenol selective O-alkylation in the PTC “liquid-liquid” system. The formation of O- and C-alkylation products during phenol alkylation was discussed in accordance with the "principle of hard and soft acids and Pearson bases". The investigated reaction of phenol with alkyl halides ensures the selectivity for chemical reactions along with other positive provisions closer to the implementation of the green chemistry task.

The formation of the mentioned compound has been followed by the methods of gas-liquid-chromatography (GLC) and thin-layer- chromatography (TLC).