Prepd by heating β-naphthol with potassium ethyl sulfate, or with alcohol and H2SO4: Yokoyama et al., Yakugaku Zasshi 78, 123 (1958); C.A. 52, 10986c (1958); from β-naphthol + p-toluenesulfonyl chloride + ethyl alcohol: Drakowzal, Klamann, Monatsh. Chem. 82, 588 (1951); from β-naphthol + H2SO4 + ethyl acetate: S. Patai, M. Bentov, J. Am. Chem. Soc. 74, 6118 (1952); from β-naphthol + triethylphosphate + p-toluenesulfonic acid: A. Bell, US 2683748 (1954 to Eastman Kodak). Thermochemical properties: M. Colomina et al., J. Chem. Thermodyn. 8, 869 (1976).