The structures of three doubly-acyl­ated 4-amino­anti­pyrine com­pounds where the aryl substituent is varied are reported and analysed in terms of their relative conformation, inter­molecular inter­actions and overall packing. The com­pounds were crystallized using the encapsulated nanodroplet crystallization (ENaCt) protocol.

Successful crystallographic structure-based drug-discovery (SBDD) support of early-stage pharmaceutical research programs requires the timely establishment of a robust crystallization system for the target protein. This enables structure determination of early high-throughput screening or fragment-screening hits, in turn maximizing the impact of SBDD on hit optimization. Here, a collection of complementary case studies are presented that demonstrate typical strategies to achieve this goal.