Potassium Trimethylsilanolate-Mediated Conversion of Dialkyl Phosphonates to Their Anhydrous Potassium Monoalkyl Phosphonates Under Mild, Non-Aqueous Conditions
Thorough Examination of a Wittig−Horner Reaction Using Reaction Calorimetry (RC-1), LabMax, and ReactIR
作者:Michael Grabarnick、Sharona Zamir
DOI:10.1021/op020075i
日期:2003.5.1
The kinetics and thermodynamics of a Wittig-Horner reaction was investigated, together with side reactions such as the hydrolysis of benzyl phosphonate. It was found that the water content in the reaction mass has a crucial effect on the rates both of the unwanted hydrolysis of the phosphonate and of the main reaction. The reaction was found to be fourth-order. That means that the reaction is very fast at the start but tails off towards the end. On the basis of the kinetic and thermodynamic parameters, a simulation of the whole process was made, including the expected concentrations of the product under the required conditions (temperature, reactor characteristics, etc.). The experimental values of the concentrations were obtained from spectra collected via a rapid reaction mode in the ReactIR (a spectrum was collected every similar to3 s). Exact agreement between experimental and theoretical values confirms the correctness of the mathematical model and enables right planning of the industrial process.
Potassium Trimethylsilanolate-Mediated Conversion of Dialkyl Phosphonates to Their Anhydrous Potassium Monoalkyl Phosphonates Under Mild, Non-Aqueous Conditions
Anhydrous potassium monoalkyl phosphonates have been prepared from the corresponding dialkyl phosphonates and potassium trimethylsilanolate under non-aqueous conditions in good to excellent yields. Simple workup procedure has been developed to afford high purity products.