Method (a) involving the action of dialkyl chlorophosphate [(RO), POCI] on dialkyl phosphoric acid [(R'O) zPO (OH)] in the presence of a tertiary organic base such as pyridine or triethylamine is similar to the procedure described previously for the preparation of tetraethyl pyrophosphate. 2 This method produces readily, and in good yield, the whole series of unsymmetrical tetraalkyl pyrophosphates. In those cases in which small ...
