Dichlorophosphonic acid-[1]naphthyl ester

Dichlorophosphoric acid-1-naphthyl ester was prepared as follows: from 1-naphthol (3.00 g, 20.81 mmol), phosphoryl chloride (1.94 mL, 20.81 mmol), triethylamine (2.9 mL, 20.81 mmol) and anhydrous diethyl ether (70 mL). After 1 hour at -78 C, the reaction was brought to room temperature and stirred for 3 hours. The crude product was obtained as an oil. The desired substance is then purified.