Prepd from phenol or its salts by the use of the ethylating agent ethyl chloride: Wohl, Ber. 39, 1953 (1906); ethyl bromide: White et al., J. Am. Chem. Soc. 46, 965 (1924); ethyl p-toluenesulfonate: Finzi, Ann. Chim. Appl. 15, 41 (1925); diethyl sulfate or triethyl phosphate: Noller, Dutton, J. Am. Chem. Soc. 55, 424 (1933). Toxicity data: Binet, Rev. Med. Suisse Romande 15, 561 (1895).