In a dry four-neck 250 mL round-bottom flask equipped with a mechanical stirrer, a thermometer, and an argon inlet were introduced at 20 °C triethylamine (21.3 g, 210 mmol), tert-butyl methyl ether (75 mL), and ethanol (9.67 g, 210 mmol). Phosphorus oxychloride (15.3 g, 100 mmol) was added dropwise in 10 min via a syringe; the temperature was maintained below −5 °C. Then, the cooling bath was removed and the white suspension was vigorously stirred during 5 h at 20 °C. The mixture was filtered and the solid was rinsed with 3 × 100 mL of diethyl ether. The solvents were removed under vacuo. The resulting crudez product was distilled under reduced pressure to afford 15.4 g (89% yield) of diethyl chlorophosphate containing 3% of triethylphosphate.

Eb₃ = 51 °C (lit:(3) Eb₁₀ = 85–87 °C).

¹H NMR (CDCl₃, 300 MHz, δ): 1.37 (6H, t, J = 6.0 Hz), 4.16–4.30 (4H, m).

¹³C NMR (CDCl₃, 75 MHz, δ): 15.6 (d, J = 7.5 Hz), 65.7 (d, J = 6.8 Hz).

 

³¹P RMN (CDCl₃, 121 MHz, δ): 4.5.