4-N-acyl-delta 5-2-oxopiperazines, a process for its preparation and combinatorial libraries thereof

摘要

A novel solution phase and solid phase synthesis of 4-N-acyl-Delta⁵-2-oxopiperazine (I) is described via a Ugi four-component condensation of an acid, an ketone or aldehyde, a protected alpha-aminoaldehyde or alpha-aminoketone and an isocyanide followed by an N-acyliminium ion cyclization facilitated by an acid, which also cleaves the product from the polymer when the reaction is conducted in the solid phase.