Ethyl 3-(1-chlorophthalazin-6-yl)-4-methylbenzoate (1.4 g) in acetonitrile (10 mL) was treated with isopropylamine (8 mL, 89 mmol). The mixture was stirred at 140° C. (sealed tube) for 15 h. The mixture was dissolved in 100 mL dichloromethane and was washed with water (20 mL), brine (20 mL), then dried over anhydrous Na2SO4, concentrated in vacuo, and purified by column chromatography eluting with 50% ethyl acetate/DCM to give ethyl 3-(1-(isopropylamino)phthalazin-6-yl)-4-methylbenzoate as a white solid.
