Synthese von trinatrium-phosphono/14C/formiat

Trisodiumphosphono/14C/formate (TPF) has been prepared in high chemical and radiochemical purity by carboxylation of sodium‐di‐n‐butylphosphite with 14CO2, subsequent alkylation with dimethyl‐sulfate to di‐n‐butylphosphonomethyl/14C/formate and dealkylation of the latter with aid of trimethylbromosilane and alkaline hydrolysis. Whereas in trisodiumphosphono/14C/formate the radioactive carbon has been observed to be stable in its position, the 14C in sodium‐di‐n‐butyl‐phosphono/14C/formate may be quantitatively exchanged with CO2.