L-Aspartic Acid → Ninhydrin

Participants

Reaction Steps

This methodology uses Nα -Boc-amino acids together with OFm side-chain protection for Asp and Glu. Asp and Glu were introduced with Boc-Asp(OFm)-OH and Boc-Glu(OFm)-OH. After coupling the last amino acid, the OFm protecting groups were selectively removed by treating the peptide resin in 50% piperidine in DMF (Dimethylformamide) for 1 h. The peptide resin was washed with DMF (3×40 mL), DCM (dicholoromethane) (3×40 mL), suspended in 15 mL of DMF, and mixed with a 6-fold excess of BOP reagent in the presence of an 8-fold excess of diisopropylamine (DIEA) for 5 h. The coupling was repeated until the resin gave the negative ninhydrin test.

Provenance & Evidence