Wikipedia
Diethyl sulfate
Diethyl sulfate is a highly toxic and likely carcinogenic chemical compound with formula (CH)SO. It occurs as a colorless, oily liquid with a faint peppermint odor and is corrosive.
Diethyl sulfate is used as an alkylating agent to prepare ethyl derivatives of phenols, amines, and thiols. It is used to manufacture dyes and textiles.