Chromatogram (205 and 254 nm) on C18 (Alltima, Grace Discovery) under gradient conditions (0 to 100% ACN, 0.01% TFA, 10 min). The product elutes as a single peak eluting at 4.43 min with trace amounts of an uncharacterised peak eluting at 5.45 min thought to be a stable conformer rather than a byproduct, pending further investigation.