Sulfuric Acid → Praziquanamine

Participants

Reaction Steps

2-(2,2-Dimethoxy-ethylamino)-N-phenethyl-acetamide hydrochloride (8.77 g, 29.0 mmol) was added to the ice-cooled sulfuric acid (8.8 ml) and the mixture was stirred for 3.5 hours at room temperature. Ice-water was added to the solution after cooling by ice and the resulting solution was extracted with dichloromethane after adjusted to pH 12 with 20% aqueous sodium hydroxide. The organic layer was washed with brine and dried with magnesium sulfate, and then the solvents were removed under reduced pressure. Recrystallization of the residue with hexane-ethyl acetate afforded 1,2,3,6,7,11b-hexahydro-pyrazino[2,1-a]isoquinolin-4-one (4.38 g, 75%).

Provenance & Evidence