[pgk]

Please, note that the working up of the old Chugaev-Tserevitinov method for “active hydrogen” determination with methylmagnesium iodide, is as follows:
After the methylmagnesium iodide preparation in methoxybenzene (anisole), unreacted methyl iodide is removed by distillation and the so prepared methylmagnesium iodide is decanted from the precipitated, unreacted magnesium.
This technique leads to lose of significant amount of the so prepared methylmagnesium iodide, which may be tolerated for analytical purposes (for samples of known mass); but it is unacceptable in synthetic chemistry.