Diethyl sulfate (DES) is an organosulfur compound with the formula (C<sub>2</sub>H<sub>5</sub>)<sub>2</sub>SO<sub>4</sub>. It occurs as a colorless, oily liquid with a faint peppermint odor. It is a toxic, combustible, and likely carcinogenic chemical compound. and ammonium salts, and ethyl thioethers. In preparing ethyl esters of fatty acids, both equivalents of the ethyl electrophile are transferred, unlike the usual alkylation of phenoxides:
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The resulting ethyl sulfate is then heated with sodium sulfate, leading to a redistribution reaction:
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Safety
Like other strong alkylating agents and especially dimethyl sulfate, diethyl sulfate is toxic It is classified as a Group 2A (probably carcinogenic to humans) carcinogen by the IARC. Experimentation with animals has suggested this compound is likely carcinogenic to humans as it was implicated in the development of laryngeal cancer. Evidence of the effects of this chemical compound on reproductive or developmental health is also lacking.
Neutralization
Dialkyl sulfates can be rendered nontoxic by treatment with aqueous ammonia.