(R)-1-chloro-4-(2-methylpiperazin-1-yl)phthalazine (JK-2, 752 mg, 2.86 mmol) was dissolved in DMF (8 mL) and N,N-diisopropylethylamine (1.5 mL). Cyclohexanecarbonyl chloride (0.498 mL, 3.72 mmol) was added and the mixture stirred at rt for 16 hours. The reaction was taken up in ethyl acetate (80 mL) and washed with aqueous K2CO3 (10%), water, and saturated sodium chloride. The organics were dried (MgSO4) and evaporated to give a yellow oil. Chromatography over silica gel with a gradient of hexanes/0-75% ethyl acetate gave an off-white foam. MS (M+H)+=373.1.
