In 2023 Veranova carried out work identifying and exemplifying a chiral resolution of an API intermediate via diastereomeric salt formation.
Problem
The route for synthesis involved a multi-step process, with the final step being purification of an unwanted diastereomer using expensive and time consuming supercritical fluid chromatography (SFC). The aim was to eliminate the need for this separation by introducing a resolution through chiral salt formation into the process.
Scope of work carried out at Veranova
- Analysis of synthetic pathway to identify the optimal step to carry out the chiral salt formation
- Screening of a wide array of chiral acids under different conditions to promote salt formation
- Identification of two hits, successfully forming chiral salts with good selectivity in the solid and liquid phases
- Selection of preferred candidate based on solid form properties, maximum yields and resolution efficiency
- Demonstration of salt formation with resolution of the desired enantiomer followed by liberation of the chirally pure free form
Outcome
The client was presented with an alternative process to expensive SFC purification during the synthesis of their API. The work was completed to tight timelines giving the option for development to be incorporated into their upcoming GMP batch.