1,4-Butane sultone:Preparation,Toxicity

1,4-butanesultone is a viscous, clear, colorless and odorless liquid which reacts in boiling water and alcohols (to 4-alkoxybutanesulfonic acid) and dissolves in many organic solvents. At temperatures below the melting point, the compound crystallizes giving "large, magnificent plates".

Preparation

A lab scale synthesis of 1,4-butanesultone starts from 4,4'-dichlorodibutyl ether (accessible from tetrahydrofuran treated with phosphorus oxychloride and concentrated sulfuric acid),which reacts with sodium sulfite forming the corresponding 4,4'-butanedisulfonic disodium salt. 

By passing it through an acidic ion exchanger, the disodium salt is converted into the disulphonic acid which forms two molecules of 1,4-butanesultone at elevated temperature and reduced pressure under elimination of water. The yields obtained range from 72 to 80%.

Toxicity

Compared to the homologous γ-sultone 1,3-propanesultone, 1,4-butanesultone is significantly less reactive as alkylating agent, but classified as mutagenic and carcinogenic.

Storage

Store at room temperature