Synthesis and purification of methyl‐13C fluoride

A 20 mmole quantity of methyl-13C fluoride at a 13C-enrichment level of 90% was prepared by a two-step synthesis starting with methanol-13C. The overall yield was 60% of methanol used. A series of gas-chromatographic treatments using Ascarite, silica gel, and Chromosorb-102 columns yielded a highly purified methyl fluoride in which the major impurities were less than 10 parts per million of carbon dioxide and 10 parts per million of methyl chloride.