To a solution of triphenylphosphine (9.00 g, 34.3 mmol) in THF (100 mL), DEAD (5.44 mL, 34.3 mmol) was added at 0° C. After stirring for 15 min, 2-(quinolin-2-yl)ethanol from Example a1 (2.97 g, 17.17 mmol) was added. After another 15 min, 8-chlorophthalazin-1(2H)-one (3.1 g, 17.17 mmol) was added. The mixture was stirred overnight at room temperature; LC-MS indicated complete conversion to the product. 1 N HCl was added (pH=4). The mixture was extracted with EtOAc (3×50 mL), the EtOAc layers were discarded. The aqueous layer was neutralized by aq.NaHCO3 and extracted with ethyl acetate (3×500 mL). The combined organic layers were washed with brine, dried over Na2SO4, filtered, and concentrated under reduced pressure. The crude product was suspended in EtOAc. The solid was filtered through a Büchner funnel. The purity of the title product was 95%.
