Optimization of the synthesis of methyl iodide using sponge iron

The optimization of the conventional synthesis of an important industrial p roduct-methyl iodide-by using iron sponge, iodine, and methanol as precurso rs is presented. The experiments were carried out under different condition s of molar ratio of the reagents, reaction and distillation temperatures, s tirring rate, and rate of addition of methanol. It is shown that the highes t yield of the product is reached at the molar ratios of methanol/iron of 1 .0 and iodine/iron higher of 1.5. The optimal temperature range for this sy nthesis is located between 53 and 109 degreesC for which the highest yields were obtained in coincidence with the temperature range at which the forma tion of FeI2 is also optimal. A relationship between the syntheses of FeI2 and the syntheses of CH3I was elaborated and it was found that the conditio ns favorable for the syntheses of FeI2 are also necessarily favorable for t he syntheses of CH3I.