Preparation activated magnesium

A variant of the Wurtz reaction is the preparation of tetrabutyltin from activated magnesium chips, butyl chloride, and stannic chloride in a hydrocarbon mixture. Only a small amount of tetrahydrofuran is required for the reaction to proceed in high yield (86). 

The Grignard reagents prepared from the activated magnesium appear to react normally with electrophiles. Thus reactions with proton donors, ketones, and carbon dioxide afford hydrocarbons, alcohols, and carboxylic acids, respectively. The reductive coupling of ketones to pinacols had also been accomplished with the activated magnesium. ... 

There is no clear evidence to identify the active material for SO2 removal in a MgAl20 stoichiometric system. Figure 13 shows results for a 50-50 mole% magnesia-alumina material prepared from magnesium hydroxide and alumina sol and calcined at various temperatures. An attempt was made to correlate SO2 removal with compound formation, as measured by X-ray diffraction, and surface area. As indicated in the figure, SO2 removal ability decreased with Increasing calcination temperature as did surface area. X-ray diffraction analysis showed spinel formation increases as... 

Salt of Salicylic Acid. A large number of salts of salicylic acid have been prepared and evaluated for therapeutic or other commercial use. Sodium salicylate has analgesic, antiinflammatory, and antipyretic activities. Magnesium salicylate, an analgesic and antiinflammatory agent, appears to have exceptional ability to relieve backaches. It is also used for the symptomatic relief of arthritis. Bismuth subsalicylate is taken orally in combination with other ingredients for protective, antacid action as well as antidiaiiheal and antiseptic effects. 

Anthracene-activated magnesium. An activated form of Mg powder is obtained by equilibration with the anthracene adduct. The method involves sonication of a mixture of Mg with anthracene (0.02 equiv.) and CH,I in I HF at 20° for 14 hours. This activated magnesium is particularly convenient for preparation of allylic Grignard reagents (11, 308)."... 

Many di-Grignard reagents can be prepared routinely from the corresponding halo compounds, provided the halogens are sufficiently separated, for example, (42), X(CH2)4X, or m- and /t-dihalo aromatics. Precautions such as dilution, low temperature, and active magnesium (particularly Mg anthracene) may be important for a good yield, particularly where the halide is easily displaced, for example benzylic. 

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