phosphorus trichloride 97%
isopropyl alcohol

In a two-necked 125 mL round flask equipped with an addition funnel and a reflux condenser fitted with a bubbler, the dry isopropyl alcohol (0.70 mmol) was added. Through the addition funnel, freshly distilled PCl₃ (0.23 mmol) was added dropwise with magnetic stirring so the temperature was kept around 0°C. After all the chloride was added, the mixture was kept under stirring at reflux for 2 h. The mixture was then kept under vacuum to remove residual HCl and finally the diisopropyl phosphonate was obtained a colorless liquid (36.6 g, 94%).

If the HCl were not completely removed, the diisopropyl phosphonate was liable to decompose.
The water can be removed from isopropyl alcohol by refluxing with CaO (200g/L) for several hours, then distilling.
The diisopropyl phosphonate can be purified by distillation obtained was 59°C - 0.2mmHg.
This particular reaction protocol can be applied to different alcohol.

¹H NMR (300 MHz, CDCl₃) 1.31, 1.32 (12H, 2d, CH₃, J_HCCH = 5.9); 4.73 (2H, dhep, CH, J_HCCH = 6.2, J_POCH = 8.5); 6.84 (1H, d, J_PH = 688.28 Hz,) 

¹³C NMR (75.42 MHz, CDCl₃) 23.19 (d, CH₃, J_CCOP = 4.8); 23.37 (d, CH₃, J_CCOP = 4.3); 70.10 (d, CH, J_COP = 5.7) 

³¹P NMR (121.42 MHz, CDCl₃) 6.90

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Lin, W. O.; Souza, M. C.; DaCosta, J. B. N.; Quím. Nova, 1995, 18 (5), 431.
Fakhraian, H.; Mirzae, A.; Organic Process Research & Development 2004, 8, 401. doi:10.1021/op049958v
Rodrigues, J. M.; Sant'Anna, C. M. R.; Rumjanek, V. M.; DaCosta, J. B. N.; Phosphorus, Sulfur, and Silicon 2010, 185, 40. doi:10.1080/10426500903444366