Comparison of three methods for the methylation of aliphatic and aromatic compounds.

We find product isolation yield and evaporation to be the main concerns in the accurate determination of isotopic composition. 1 H/2 H exchange reactions are too slow to cause measurable isotope fractionation over the typical duration and reaction conditions used in methylation. Thus, we are able to recommend continued use of acidic catalysts in such methylation reactions for both aliphatic and aromatic compounds.