This thesis describes a new microwave-assisted method for the synthesis of poly-deuterated anilines and pyridines. The microwave mediated deuteration of aniline derivatives both with and without a platinum catalyst has been studied. Selectivity and yields are compared, showing the well established electronic selectivity of deuteration in the absence of a platinum catalyst, and a selectivity governed by steric factors for the platinum catalysed exchange. Differences in percentage yield can be explained for each method but vary greatly with changes in substrate. The ability for platinum catalysed exchange to deuterate aliphatic positions has also been observed and a tentative mechanism is proposed for the exchange of protons on substituents. Following investigation into the two different catalysts, the yield for the microwave assisted procedure is good, and high levels of deuterium incorporation are observed with only a single cycl