Sodium, dispersions reaction with liquid ammonia

More important are the compounds formed by acidic hydrocarbons such as cyclopentadiene, indene, and acetylenes. These are obtained by reaction with sodium in liquid ammonia or, more conveniently, sodium dispersed in THF, glyme, diglyme, or dimethylformamide (DMF). 

In contrast to the liquid ammonia reaction trisodiumphosphide, Na3P, is the major product resulting from the reaction of white phosphorus (red phosphorus, proved less satisfactory) with sodium potassium alloy or with sodium dispersions in inert organic media (e.g. toluene) at temperatures varying from 80 to 145 °C The phosphide Na3P reacts readily with methyl halides in glyme solvents to afford methylphosphorus compounds in ca. 60% overall yields under optimum... 

Bipyridyl can be prepared from pyridine, forming first with sodium dispersed in liquid ammonia a transient pyridine radical, which is dimerised in the reaction mixture to 4,4 -tetrahydrobipyridyl. Its oxidation with air yields an end-product of about 90% purity. 

The reduction of either Fe(CO)s or Fe3(CO)i2 with sodium metal in liquid ammonia 21) or of Fe3(CO)i2 with sodium dispersion or amalgam in tetrahydrofuran or other ethereal solvents 51) gives the anion [Fe(CO)4]. The reduction in ethereal solvents is especially valuable in providing a facile means of obtaining [Fe(CO)4] in the absence of hydroxylic solvents or nitrogen bases, both of which interfere with reactions of [Fe(CO)4] with certain reagents, especially acid chlorides. 

Degradation of the polysaccharide during methylation can be minimized by performing the reaction at low temperatures and in an atmosphere of nitrogen. Methylation is facilitated by simultaneous deacetylation and methylation of the polysaccharide acetate dispersed in an inert solvent IJiS), Fully methylated polysaccharides are obtained only after repeated methylations, which are often completed by a final methylation with a mixture of silver oxide and methyl iodide. Resistant hydroxyl groups may be methylated by the alternate addition of sodium metal and methyl iodide to the polysaccharide dispersed in liquid ammonia... 

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