Context: obtaining precipitates in the CombiUgi project

Ugi reactions in methanol where the solution is supersaturated with Ugi product may give false negatives for precipitation. For example, a Ugi product rapidly crystallized at the 17th hour (RESULT0003) after addition of all reagents, while appearing as a clear solution at the 15th hour (RESULT0002). It is therefore recommended that the vials be submitted to vortexing (15 s) prior to taking a picture.