Preparation of deuterated methyl iodide through trimethylsulfoxonium iodide intermediate

Since deuterium (D) is different from its most abundant isotope hydrogen (H), the additional neutron makes a notable difference in the properties of deuterated compounds. While drug molecules easily transform to metabolites by metabolic enzymes that the body can excrete, deuterium introducing to drugs appears to strengthen the resistance of drugs toward metabolism. The higher the stability, the longer the drug can work, which may result in lower dosage, therefore less side effects [1].As a potential source of deuteromethyl group, methyl iodide-d3 is very valuable compound in deuterium chemistry, which is used as an intermediate in the manufacture of some pharmaceuticals, in methylation processes and in the field of microscopy [2].To synthesis of methyl iodide-d3 we prepared trimethylsulfoxonium iodide from dimethylsulfoxide and methyl iodide [3]. The isotope exchange of this salt was accomplished with the deuterium oxide and a catalytic amount of base. The obtained deuterated salt, upon pyrolysis, is converted back to the deuterated starting materials