(3-Bromophenyl)-(2-methylquinolin-4-yl)amine (71). 71 is prepared from 70 by the procedure of Example 1 Step 3. Step 2. 3′-(2-Methylquinolin-4-ylamino)biphenyl-3-carbaldehyde (73). To a suspension of 71 (294 mg, 0.94 mmol) in toluene (9.6 mL) under N2 were sequentially added saturated NaHCO3 (aq. 3.8 mL), a solution of 72 (199 mg, 1.33 mmol) in EtOH (6.7 mL), and PdCl2(Ph3P)3 (32 mg, 0.046 mmol). The reaction was heated at 80° C. for 21 hours before it was allowed to cool to room temperature. The reaction mixture was extracted with ethyl acetate (40 mL) and washed with water (15 mL), brine (15 mL). The ethyl acetate extracts were dried over anhydrous magnesium sulfate and concentrated. The residue was chromatographed on silica gel (dichloromethane to 20:1 dichloromethane/methanol) to give 73 as a yellow solid (219 mg, 68.9%). Step 3.3′-(3,4-Dihydro-1H-isoquinolin-2-ylmethyl)biphenyl-3-yl]-(2-methylquinolin-4-yl)amine. To a solution of 73 (102 mg, 0.301 mmol) in dichloroethane (3.0 mL) under N2 was added 40 (0.04 mL, 0.315 mmol). The reaction was stirred for 24 minutes before the sequential addition of NaBH(OAc)3 (94 mg, 0.444 mmol) and AcOH (0.02 mL, 0.349 mmol). The reaction was stirred for 19 hours and then extracted with ethyl acetate (2×30 mL). The ethyl acetate extracts were washed with 2 N NaOH (aq. 15 mL), brine (15 mL), dried (MgSO4), and concentrated. The residue was chromatographed on silica gel (dichloromethane to 30:1 to 20:1dichloromethane/methanol) to give the desired product as a yellow solid (75 mg, 55%).
