Sodium hydride → 3-(1-Benzyloxy-7-chloro-isoquinolin-6-yloxy)-cyclobutylamine

To a suspension of 459 mg (11.5 mmol) of sodium hydride (60%) in 16 mL of dimethyl acetamide was added a solution of 333 mg (3.82 mmol) of 3-amino-cyclobutanol (50) in 8 ml of dimethyl acetamide. After stirring for 60 min at room temperature a solution of 1.00 g (3.48 mmol) of 1-benzyloxy-7-chloro-6-fluoro-isoquinoline (11) in 16 ml of dimethyl acetamide was added and stirring was continued first at room temperature, then for 2 h at 50° C. until the reaction went to completion. The reaction was quenched by addition of water and the reaction mixture was extracted three times with a mixture of dichloromethane and 2-propanol (3:1). The combined organic layers were evaporated, water was added and the crude product was subjected to lyophilization to remove remainders of dimethyl acetamide. The obtained crude product was purified by silica gel chromatography to yield 377 mg of the title compound (51) as a mixture of diastereoisomers. Rt=0.85 min (Method H). Detected mass: 355.1 (M+H+).