Reaction SMILES: [CH2:1]([NH:3][C:4]([NH:6][C:7]1[CH:12]=[CH:11][C:10]([C:13]2[N:14]=[C:15]([N:26]3[CH2:31][CH2:30][O:29][CH2:28][C@@H:27]3[CH3:32])[C:16]3[CH2:22][CH2:21][N:20]([CH2:23][CH3:24])[C@@H:19]([CH3:25])[C:17]=3[N:18]=2)=[CH:9][CH:8]=1)=[O:5])[CH3:2].C(NC(NC1C=CC(C2N=C(N3CCOC[C@@H]3C)C3CCNC(C)C=3N=2)=CC=1)=O)C.CN(C)C=O.C(=O)C.C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+].C(O)(=O)C>[OH-].[Na+]>[CH2:1]([NH:3][C:4]([NH:6][C:7]1[CH:8]=[CH:9][C:10]([C:13]2[N:14]=[C:15]([N:26]3[CH2:31][CH2:30][O:29][CH2:28][C@@H:27]3[CH3:32])[C:16]3[CH2:22][CH2:21][N:20]([CH2:23][CH3:24])[C@H:19]([CH3:25])[C:17]=3[N:18]=2)=[CH:11][CH:12]=1)=[O:5])[CH3:2]
Reactant: CCNC(=O)Nc1ccc(-c2nc3c(c(N4CCOC[C@@H]4C)n2)CCN(CC)[C@H]3C)cc1
Agent: CC(=O)O[BH-](OC(C)=O)OC(C)=O
Agent: CC=O
Agent: CCNC(=O)Nc1ccc(-c2nc3c(c(N4CCOC[C@@H]4C)n2)CCNC3C)cc1
Solvent: CN(C)C=O
Solvent: CC(=O)O
Product: CCNC(=O)Nc1ccc(-c2nc3c(c(N4CCOC[C@@H]4C)n2)CCN(CC)[C@@H]3C)cc1
Temperature: 25 °C
Reaction time: 8 h

Procedure:
and 1-ethyl-3-(4-((S)-7-ethyl-8-methyl-4-((S)-3-methylmorpholino)-5,6,7,8-tetrahydropyrido[3,4-d]pyrimidin-2-yl)phenyl)urea (ws2): (1-Ethyl-3-(4-(8-methyl-4-((S)-3-methylmorpholino)-5,6,7,8-tetrahydropyrido[3,4-d]pyrimidin-2-yl)phenyl)urea (0.172 g, 0.419 mmol) in dry N,N-Dimethylformamide (2.00 mL, 25.8 mmol) at 0° C. was added Acetaldehyde (0.0236 mL, 0.420 mmol). The reaction mixture was stirred at 0° C. for 5 minutes the added Sodium triacetoxyborohydride (0.182 g, 0.859 mmol) followed by Acetic acid (0.0476 mL, 0.838 mmol). The reaction mixture was allowed to warm slowly to room temperature and stirred overnight. The reaction mixture was diluted with 1 M NaOH, extracted three times with 10% MeOH in dichloromethane, dried over Magnesium sulfate, filtered, and concentrated. The reaction mixture was redissovled in dry N,N-Dimethylformamide (2.00 mL, 25.8 mmol) cooled at 0° C., then added Acetaldehyde (0.0236 mL, 0.420 mmol). The reaction mixture was stirred at 0° C. for 5 minutes then added Sodium triacetoxyborohydride (0.181 g, 0.854 mmol) followed by Acetic acid (0.0476 mL, 0.837 mmol). The reaction mixture was stirred for 3 days. The reaction mixture was diluted with 1M NaOH, extracted three times with 10% MeOH in dichloromethane, dried over Magnesium sulfate, filtered, concentrated, purified by HPLC, and the diastereomers were separated by SFC. R Diastereomer (ws1): 1H NMR (400 MHz, DMSO) δ 8.66 (s, 1H), 8.17 (d, J=8.7, 2H), 7.47 (d, J=8.8, 2H), 6.19 (t, J=5.6, 1H), 4.12 (d, J=6.7, 1H), 3.87 (d, J=11.1, 1H), 3.73 (dd, J=11.3, 2.7, 1H), 3.64-3.49 (m, 4H), 3.47-3.38 (m, 2H), 3.16-3.09 (m, 2H), 3.01-2.93 (m, 1H), 2.80 (dq, J=14.5, 7.3, 1H), 2.67 (t, J=7.4, 1H), 2.60-2.53 (m, 1H), 2.41-2.31 (m, 1H), 1.42 (d, J=6.6, 3H), 1.18 (d, J=6.6, 3H), 1.14 (t, J=7.2, 3H), 1.06 (t, 3H). LC/MS-m/z+439.3 (M+H)+; and S-Diastereomer (ws2): 1H NMR (400 MHz, DMSO) δ 8.65 (s, 1H), 8.17 (d, J=8.7, 2H), 7.47 (d, J=8.8, 2H), 6.19 (t, J=5.5, 1H), 4.08 (d, J=6.7, 1H), 3.86 (d, J=11.3, 1H), 3.71-3.55 (m, 5H), 3.39 (d, J=11.4, 1H), 3.16-3.08 (m, 2H), 2.90 (dd, J=11.6, 4.7, 1H), 2.74 (dq, J=14.3, 7.2, 1H), 2.69-2.53 (m, 3H), 2.47-2.40 (m, 1H), 1.38 (d, J=6.6, 3H), 1.29 (d, J=6.6, 3H), 1.13 (t, J=7.2, 3H), 1.07 (t, 3H).