Answer to Question #125828 in Organic Chemistry for Kamli Ramli

Question

Give all methods for the preparation of organosodium reagents.

Answer 1

Transmetallation routes .

In the original work the alkylsodium compound was accessed from the dialkylmercury compound by transmetallation. For example, diethylmercury in the Schorigin reaction or Shorygin reaction:^[3][4][5]

(C₂H₅)₂Hg + 2 Na → 2 C₂H₅Na + Hg

The high solubility of lithium alkoxides in hexane is the basis of a useful synthetic route:^[6]

LiCH₂SiMe₃ + NaO–t–Bu → LiOt–Bu + NaCH₂SiMe₃

Deprotonation routes .

For some acidic organic compounds, the corresponding organosodium compounds arise by deprotonation. Sodium cyclopentadienide is thus prepared by treating sodium metal and cyclopentadiene:^[7]

2 Na + 2 C₅H₆ → 2 NaC₅H₅ + H₂

Sodium acetylides form similarly. Often strong sodium bases are employed in place of the metal. Sodium methylsulfinylmethylide is prepared by treating DMSO with sodium hydride:^[8]

CH₃SOCH₃ + NaH → CH₃SOCH−

2Na⁺ + H₂

Metal-halogen exchange .

Trityl sodium can be prepared by metal-halogen exchange. This method is used in preparing trityl sodium:^[9]

Ph₃CCl + 2 Na → Ph₃CNa + NaCl

Other methods .

Sodium also reacts with polycyclic aromatic hydrocarbons via one-electron reduction. With solutions of naphthalene, it forms the deeply coloured radical sodium naphthalenide, which is used as a soluble reducing agent:

C₁₀H₈ + Na → Na⁺[C₁₀H₈]^{−•}

The related anthracene as well as potassium derivatives are well known.