Reaction SMILES: [CH2:1]([N:3]1[C:7]2=[N:8][C:9]([CH2:48][CH3:49])=[C:10]([CH2:19][NH:20][C:21]([C:23]3[CH:28]=[C:27]([CH3:29])[CH:26]=[C:25]([C:30]([NH:32][CH2:33][C:34]4[CH:35]=[C:36]([C:40]5[CH:45]=[CH:44][CH:43]=[C:42]([CH:46]=O)[CH:41]=5)[CH:37]=[CH:38][CH:39]=4)=[O:31])[CH:24]=3)=[O:22])[C:11]([NH:12][CH:13]3[CH2:18][CH2:17][O:16][CH2:15][CH2:14]3)=[C:6]2[CH:5]=[N:4]1)[CH3:2].[CH3:50][C@H:51]1[CH2:56][NH:55][CH2:54][CH2:53][N:52]1C(OC(C)(C)C)=O.C(O)(=O)C.C(O[BH-](OC(=O)C)OC(=O)C)(=O)C>CS(C)=O>[CH2:1]([N:3]1[C:7]2=[N:8][C:9]([CH2:48][CH3:49])=[C:10]([CH2:19][NH:20][C:21]([C:23]3[CH:28]=[C:27]([CH3:29])[CH:26]=[C:25]([C:30]([NH:32][CH2:33][C:34]4[CH:35]=[C:36]([C:40]5[CH:45]=[CH:44][CH:43]=[C:42]([CH2:46][N:55]6[CH2:54][CH2:53][NH:52][C@@H:51]([CH3:50])[CH2:56]6)[CH:41]=5)[CH:37]=[CH:38][CH:39]=4)=[O:31])[CH:24]=3)=[O:22])[C:11]([NH:12][CH:13]3[CH2:14][CH2:15][O:16][CH2:17][CH2:18]3)=[C:6]2[CH:5]=[N:4]1)[CH3:2]
Reactant: CCc1nc2c(cnn2CC)c(NC2CCOCC2)c1CNC(=O)c1cc(C)cc(C(=O)NCc2cccc(-c3cccc(C=O)c3)c2)c1
Reactant: C[C@H]1CNCCN1C(=O)OC(C)(C)C
Agent: CC(=O)O[BH-](OC(C)=O)OC(C)=O
Solvent: CC(=O)O
Solvent: CS(C)=O
Product: CCc1nc2c(cnn2CC)c(NC2CCOCC2)c1CNC(=O)c1cc(C)cc(C(=O)NCc2cccc(-c3cccc(CN4CCN[C@@H](C)C4)c3)c2)c1
Temperature: 25 °C
Reaction time: 8 h
Yield: 67.3 %

Procedure:
N-{[1,6-Diethyl-4-(tetrahydro-2H-pyran-4-ylamino)-1H-pyrazolo[3,4-b]pyridin-5-yl]methyl}-N′-[(3′-formyl-3-biphenylyl)methyl]-5-methyl-1,3-benzenedicarboxamide (30 mg, 0.046 mmol), 1,1-dimethylethyl (2S)-2-methyl-1-piperazinecarboxylate (91 mg, 0.46 mmol, 10 eq) and acetic acid (2.61 μL, 0.046 mmol, 1 eq) were dissolved in DMSO (1.5 mL). The mixture was stirred in a VX-2500 Multi-Tube Vortexer overnight at room temperature. MP-triacetoxyborohydride (137 mg, 0.319 mmol, 7 eq) was then added and the mixture was stirred again in the VX-2500 Multi-Tube Vortexer overnight at room temperature. The reaction mixture was filtered through a polypropylene cartridge (10 mL tube) on Bohdan Miniblock (Artisian Scientific, Chanpaign, Ill., USA; http://www.artisan-scientific.com/51413.htm) in a reaction tube and concentrated in a Glas-Col evaporator. Methanol (2 mL), then hydrochloric acid (5 μL), were added for the deprotection of 1,1-dimethylethyl (2S)-4-[(3′-{[({3-[({[1,6-diethyl-4-(tetrahydro-2H-pyran-4-ylamino)-1H-pyrazolo[3,4-b]pyridin-5-yl]methyl}amino)carbonyl]-5-methylphenyl}carbonyl)amino]methyl}-3-biphenylyl)methyl]-2-methyl-1-piperazinecarboxylate. The vial containing the reaction mixture was closed and stirred in a Glas-Col evaporator for overnight at 60° C. The reaction mixture was then concentrated and purified using a Gilson HPLC with a water-acetonitrile-with-0.1% TFA buffer. The desired product fractions were combined, filtered through amine cartridge (500 mg) on a Bohdan Miniblock and concentrated in a Glas-Col evaporator, giving 22.99 mg (61.2%) of the title compound. LC-MS m/z 743.4 (M+H)+, 1.27 min (ret time); 1H NMR (500 MHz, DMSO-d6) δ 0.86 (d, J=6.35 Hz, 3 H), 1.24 (t, J=7.32 Hz, 3 H), 1.33 (t, J=7.08 Hz, 3 H), 1.52-1.58 (m, 2 H), 1.83-1.97 (m, 2 H), 2.40 (s, 3 H), 2.59-2.65 (m, 4 H), 2.70-2.76 (m, 1 H), 2.96 (q, J=7.49 Hz, 2 H), 3.16 (d, J=5.37 Hz, 3 H), 3.54 (t, J=10.50 Hz, 2 H), 3.83-3.89 (m, 2 H), 4.09 (q, J=5.37 Hz, 2 H), 4.32 (q, J=7.16 Hz, 2 H), 4.54 (d, J=5.86 Hz, 4 H), 7.05 (d, J=7.81 Hz, 1 H), 7.26 (d, J=7.32 Hz, 1 H), 7.31 (d, J=7.81 Hz, 1 H), 7.40 (ddd, J=12.09, 7.69, 7.57 Hz, 2 H), 7.47-7.53 (m, 3 H), 7.58 (s, 1 H), 7.80 (s, 1 H), 7.85 (s, 1 H), 8.00 (s, 1 H), 8.14 (s, 1 H), 8.97 (t, J=5.86 Hz, 1 H), 9.11 (t, J=5.86 Hz, 1 H).