http://jeandenoir.free.fr/content/folders/encyclo/matieres/chimie/organique/heteroatomes/organometaliques/alcalins/index.htm (http://jeandenoir.free.fr/content/folders/encyclo/matieres/chimie/organique/heteroatomes/organometaliques/alcalins/index.htm)
Organoalkalis are prepared by action of an organic halide on the metal itself. This is how one prepares butyllithium:
C4H9Br + 2 Li ---> C4H9Li + LiBr
One generally works in ether. The presence of water must be excluded, and other protonic compounds which may be decomposed by organo-alkalis. One may also substitute an acidic hydrogen of a hydrocarbon for the metal of an organo-alkali without acid. It is thus that benzyl sodium is prepared:
C6H5-CH3 + R-Na ---> C6H5-CH2Na + RH
Organosodium and organolithium compounds are used as polymerization catalysts for conjugated dienes.
Looks like if ethyl sodium is refluxed in toluene, ethane goes away, driving things to the right. (Ultimately, you still use two sodiums, for your ethyl sodium was prepared from ethyl bromide using the first reaction.)