Synthesis of chloroacetic acid and glycine labeled with radioactive carbon in the carboxyl' group.

In order to investigate certain aspects of protein metabolism, it was desired to prepare glycine labeled with radioactive carbon. The method of preparation was chosen with the object of obtaining the highest possible yields, and techniques suitable for handling small amounts of material were used throughout. The reactions employed and the yields obtained were as follows: The synthesis involves three steps; namely, conversion of sodium acetate to acetic acid (yield, 98 per cent), chlorination to monochloroacetic acid with PCls in the presence of phosphorus and iodine (yield, 70 to 90 per cent), and amination with ammonia in the presence of ammonium carbonate (yield, 80 to 90 per cent).