Racemic Resolution of Praziquantel and Praziquanamine

 

Hazard and Risk Assessment:


Procedure:
MNR11-16 (6.65 g, 17.85 mmol) was dissolved in a mixture of EtOH (35 mL) and 1M HCl (180 mL) and heated to reflux for 14 h. The reaction was then allowed to cool and the EtOH was removed under reduced pressure. The mixture was then basified with NaOH to pH 12 and extracted with EtOAc (3 x 150 mL). The organic fractions were combined, dried over magnesium sulphate, filtered and concentrated under reduced pressure to give an orange solid (1.895 g, 40%).

Why so low recovery?? I thought removing the EtOH would increase the recovery.