n,n-Diethylformamide

N,N-Diethylformamide (DEF, CAS 617-84-5) is a tertiary amide solvent with no assigned E-code, also referenced under the synonyms Formyldiethylamine and NSC 6242. It belongs to the formamide family and is fully miscible with most organic solvents and water.

In pharmaceutical synthesis, DEF functions as a polar aprotic reaction medium that stabilises reactive intermediates and improves yields in condensation and cyclisation steps. In polymer processing and printing ink formulation, it acts as a high-boiling carrier solvent, controlling viscosity and resin dissolution rates during compounding and coating operations.

DEF is supplied under REACH registration and is available in standard industrial grades. Typical packaging includes drums and IBC containers sized for B2B procurement volumes. Buyers should confirm purity specifications and SDS documentation directly with the supplier to ensure compliance with applicable workplace and transport regulations.