Non natural amino acids as potential antimicrobial agents: Synthesis of an analogue of anticapsin and diketopiperazine scaffolds

An attempt to synthesise a non natural amino acid, analogue of anticapsin is described. This amino acid is interesting for its potential as antimicrobial agent. In order to synthesise the compound, the 1,4-disubstituted piperazine-2,5-diones (DKP) core has to be coupled to an appropriate side chain. The DKP is generated through a one pot synthesis starting from a suitable amine, chloroacetyl chloride and an aqueous base. The cyclisation in situ was here optimised and is obtained by employing the phase transfer catalyst, benzyltriethylammonium chloride (TEBA). The side chain is generated through different steps starting from a methyl- or benzyl-amine, methyl propiolate and acryloyl chloride.