To a solution of 3-(3-(3,4-dihydroisoquinolin-2(1H)-yl)-2-hydroxypropoxy)benzaldehyde (200 mg, 0.64 mmol) in DCM (15 mL) was added 1H-pyrazol-3-amine (80 mg, 0.96 mmol). The solution was heated at 60° C. for 0.5 h. NaBH(OAc)3 (204 mg, 0.96 mmol) was then added into the reaction mixture which was heated at 60° C. for another 1 h. The reaction mixture was quenched by adding 1 N HCl aqueous solution and diluted with DCM and washed with NaHCO3 aqueous solution. The separated organic layer was concentrated and the crude product was purified by preparative HPLC purification. (26 mg, yield 11%). MS (ESI+) e/z: 379.1 [M+1]. 1H NMR (MeOD, 400 MHz), δ ppm: 7.33-7.18 (m, 7H), 7.00-6.96 (m, 2H), 6.84-6.80 (m, 1H), 4.48-4.44 (m, 3H), 4.28 (s, 1H), 4.06-3.98 (m, 2H), 3.59-3.56 (m, 2H), 3.42-3.39 (m, 2H), 3.20-3.15 (m, 2H).
