In chemistry, a phosphorochloridate is a class of organophosphorus compounds with the formula (RO)<sub>2</sub>P(O)Cl (R = organic substituent). They are tetrahedral in shape, akin to regular phosphates (OP(OR)<sub>3</sub>). They are usually colorless and sensitive toward hydrolysis. They are oxidized derivatives of phosphorochloridites, which have the formula (RO)<sub>2</sub>PCl. A popular example is diethyl phosphorochloridate.
Phosphochloridites are precursors to phosphate esters:
Other nucleophiles have been employed, such as azide.