Catalytic Effect of Tertiary Amines on the Etherification of Phenethyl Alcohol with Dimethyl Sulfate

Abstract

Methylation reaction of phenethyl alcohol with dimethyl sulfate was studied in order to pursue the optimum reaction conditions for the synthesis of methyl phenethyl ether.
When a mixture of phenethyl alcohol, 50% aqueous solution of sodium hydrox ide dimethyl sulfate, benzene and a catalytic amount of tributylamine (TBA) was stirred at 40°C for 3 h, methyl phenethyl ether was obtained in 92% yield. The yield of methyl phenethyl ether increased as the amount of TBA was increased. Not only tertiary amines such as tributyland trioctylamine but also guar ternary ammonium chlorides such as tetrabutylammonium and trioctylmethylammonium chloride served as the most effective catalysts for this etherification.
In addition, four kinds of aromatic alcohols were also alkylated with dimethy l and diethyl sulfate to give methyl and ethyl ethers in a similar procedure.