Add 3-(4-nitro-phenyl)-propionaldehyde (0.390 g, 2.18 mmol to 7-bromo-isoquinoline-5-sulfonic acid (2-amino-ethyl)-amide, [0.75 g (87% purity), 1.98 mmol) in 110 ml (6:5) CH2Cl2/MeOH. Stir the mixture for 18 h, then placed in an icebath. Add NaBH4 (0.150 g, 3.96 mmol) and stir for 1 h at 0° C. and 2 h at room temperature. Concentrate the reaction mixture, dissolve the residue in CH2Cl2/MeOH and load onto a silica gel column. Elute with 100% CH2Cl2, then a gradient of 0-10% (2M NH3 in MeOH) in CH2Cl2 to give 0.677 g of 7-bromo-isoquinoline-5-sulfonic acid {2-[3-(4-nitro-phenyl)-propylamino]-ethyl}-amide, as a yellow gum in 68% yield. ES Positive Ion MS [M+H]+ ions observed: m/z 493 (79 Br) and m/z 495 (81Br).
