100 mg (0.36 mmol) 4-(5-Chloro-isoquinolin-6-yloxy)-cyclohexanone (79) were dissolved in 10 ml methanol. After adding 73 mg (0.73 mmol) triethyl amine, 108 mg (1.09 mmol) cyclohexylamine, 218 mg (3.63 mmol) acetic acid and freshly dried molecular sieves, the reaction was stirred at room temperature. After 30 minutes, a solution of 68 mg (1.09 mmol) sodium cyanoborohydride in 2 ml methanol was added and the reaction was kept at room temperature until complete conversion was achieved. For working up, the reaction mixture was filtered and the filtrate was brought to alkaline pH by adding solid NaHCO3. After evaporation of the solvent, the residue was taken up in H2O and extracted three times with dichloromethane. The combined organic layers were dried over MgSO4 and evaporated. Final purification by preparative HPLC gave 69 mg of the desired product as trifluoroacetate, which was dissolved in 2 N HCl and lyophilized, to yield 45 mg of the corresponding HCl-salt. Rt=1.08/1.15 min (Method #1). Detected mass: 359.3/361.3 (M+H+).
