A mixture of 1-ethyl-4-chloro-6-acetamido-1H-pyrazolo[3,4-b]quinoline (0.2 g, 0.7 mmol), cyclohexanemethylamirie (0.5 ml, 3.5 mmol) and DMSO (3 ml) is heated at 110° C. for 6 hours. The reaction mixture is poured into water (50 ml), extracted with CH2Cl2 (4×25 ml), and the organic layers are combined and evaporated. The residue is slurried in ether, and a yellow solid is collected by filtration and recrystallized from ethanol/ethyl acetate to afford 200 mg of 1-ethyl-6-acetamido-N-(cyclohexylmethyl)-1H-pyrazolo[3,4-b]quinolin-4-amine, m.p. 277°-278° C.
