7.1 g of 2-(2-chloroacetamidopropyl)-4-phenyl-1(2H)-isoquinolone, 3.7 g of phthalimide and 3.7 g of potassium carbonate were added to 50 ml of dimethylformamide, and the mixture was stirred at 80° C. for 5 hours. The resulting reaction mixture was poured into water and the precipitated crystals were collected by filtration, washed with water and dried in air. The resulting crystals and 2 g of hydrazine hydrate were added to 100 ml of ethanol and the mixture was heated at reflux for 3 hours. After allowing the mixture to cool, 5 ml of concentrated hydrochloric acid was added to the resulting reaction mixture and the mixture was stirred for 5 hours. The solvent was then distilled off, and water was added to the residue, followed by thoroughly stirring. The mixture was filtered and the filtrate was rendered neutral with a 10% aqueous solution of sodium hydroxide. The precipitated was extracted with dichloromethane, and the extract was washed with water and dried. The solvent was distilled off and the resulting crystals were recrystallized from a mixture of ethyl acetate and petroleum ether to obtain 2.3 g (34% yield) of 2-(2-aminoacetamidopropyl)-4-phenyl-1(2H)-isoquinolone having a melting point of 141° C. as colorless needles.
