Dibutoxymethane

UsesFormaldehyde dibutyl acetal is a halogen-free and less toxic solvent that can be used to solubilize commercial low-density polyethylene (LDPE) samples to analyze molecular weight distribution using gel permeation chromatography (GPC). It can also be used as a reactant to prepare butoxymethyltriphenylphosphonium iodide, which is used for carbon homologation and also as a useful key intermediate in organic synthesis.

General DescriptionFormaldehyde dibutyl acetal is an acetal used in the manufacture of synthetic resins, antiseptics, deodorants, and fungicides. It is also used as a fuel additive to increase the octane number of gasoline or the n-cetane number of diesel fuels and reduce smoke and particulate emissions.

PreparationA flask containing 15 gm (0.5 mole) of paraformaldehyde, 74 gm (1.0 mole) of η-butyl alcohol, and 2.0 gm of anhydrous ferric chloride is refluxed for 10 hr. The lower layer of 3-4 ml of material is discarded and then 50 ml of 10% aqueous sodium carbonate solution is added to remove the ferric chloride as ferric hydroxide. The product is shaken with a mixture of 40 ml of 20% hydrogen peroxide and 5 ml of 10% sodium carbonate solution at 45°C in order to remove any remaining aldehyde. The product is also washed with water, dried, and distilled from excess sodium metal to afford 62 gm (78%).