Tetrahydrofuran ( solvent, K.F ≤ 0.05%, 9 L/Kg, 270 L) (1) is charged into a glass-lined reactor, equipped with a stirrer and a jacket for temperature control.

Triethylamine (reagent, 0.52 L/Kg, 15.6 L, K.F ≤ 0.1%) (2) is then added and a solution of phosphorus oxychloride (reagent, 0.32 L/Kg, 9.6 L) in tetrahydrofuran (solvent, 1 L/Kg, 30 L, K.F ≤ 0,05%) (3) is added while the temperature is kept at -40/-35º C.

Спасибо!