Reaction SMILES: [CH:1]1([C:4]([N:6]2[CH2:11][CH2:10][N:9]([C:12]([C:14]3[CH:15]=[C:16]([CH:20]4[C:25]5=[N:26][NH:27][C:28](=[O:33])[C:29]6[CH:30]=[CH:31][CH:32]=[C:23]([C:24]=65)[NH:22][CH:21]4[C:34]4[CH:41]=[CH:40][C:37]([CH:38]=[O:39])=[CH:36][CH:35]=4)[CH:17]=[CH:18][CH:19]=3)=[O:13])[CH2:8][CH2:7]2)=[O:5])[CH2:3][CH2:2]1.[CH3:42][NH:43][CH3:44].[BH4-].[Na+].[CH3:47][OH:48]>>[CH:1]1([C:47]([N:43]2[CH2:44][CH2:10][N:9]([C:12]([C:14]3[CH:15]=[C:16]([CH:20]4[C:25]5=[N:26][NH:27][C:28](=[O:33])[C:29]6[CH:30]=[CH:31][CH:32]=[C:23]([C:24]=65)[NH:22][CH:21]4[C:34]4[CH:41]=[CH:40][C:37]([CH2:4][N:6]([CH3:11])[CH3:7])=[CH:36][CH:35]=4)[CH:17]=[CH:18][CH:19]=3)=[O:13])[CH2:8][CH2:42]2)=[O:48])[CH2:3][CH2:2]1.[CH:1]1([C:4]([N:6]2[CH2:11][CH2:10][N:9]([C:12]([C:14]3[CH:15]=[C:16]([CH:20]4[C:25]5=[N:26][NH:27][C:28](=[O:33])[C:29]6[CH:30]=[CH:31][CH:32]=[C:23]([C:24]=65)[NH:22][CH:21]4[C:34]4[CH:35]=[CH:36][C:37]([CH2:38][OH:39])=[CH:40][CH:41]=4)[CH:17]=[CH:18][CH:19]=3)=[O:13])[CH2:8][CH2:7]2)=[O:5])[CH2:3][CH2:2]1
Reactant: CO
Reactant: O=Cc1ccc(C2Nc3cccc4c(=O)[nH]nc(c34)C2c2cccc(C(=O)N3CCN(C(=O)C4CC4)CC3)c2)cc1
Reactant: CNC
Agent: [BH4-]
Agent: [Na+]
Product: CN(C)Cc1ccc(C2Nc3cccc4c(=O)[nH]nc(c34)C2c2cccc(C(=O)N3CCN(C(=O)C4CC4)CC3)c2)cc1
Product: O=C(c1cccc(C2c3n[nH]c(=O)c4cccc(c34)NC2c2ccc(CO)cc2)c1)N1CCN(C(=O)C2CC2)CC1
Temperature: 25 °C
Reaction time: 0.67 h
Yield: 19 %
Yield: 9 %

Procedure:
A mixture of 4-(9-(3-(4-(cyclopropanecarbonyl)piperazine-1-carbonyl)phenyl)-3-oxo-3,7,8,9-tetrahydro-2H-pyrido[4,3,2-de]phthalazin-8-yl)benzaldehyde (20 mg, 0.04 mmol) and 33% dimethylamine aq solution (10 mg, 0.07 mmol) in methanol (10 mL) was stirred at room temperature for 40 min. Then the mixture was cooled to 0° C. Sodium borohydride (2 mg, 0.06 mmol) was added. After the addition, the mixture was stirred at this temperature for 2 hr. Methanol was removed under reduced pressure. The residue was washed with ethyl acetate/methanol (10/1) and filtered. The filtrate was concentrated to give the crude product. The crude product was purified by prep-HPLC to give the compound 9-(3-(4-(cyclopropanecarbonyl)piperazine-1-carbonyl)phenyl)-8-(4-((dimethylamino)methyl)phenyl)-8,9-dihydro-2H-pyrido[4,3,2-de]phthalazin-3(7H)-one (4 mg, yield 19%) and 9-(3-(4-(cyclopropanecarbonyl)piperazine-1-carbonyl)phenyl)-8-(4-(hydroxymethyl)phenyl)-8,9-dihydro-2H-pyrido[4,3,2-de]phthalazin-3(7H)-one (2 mg, yield 9%) as light yellow solids. 9-(3-(4-(cyclopropanecarbonyl)piperazine-1-carbonyl)phenyl)-8-(4-((dimethylamino)methyl)phenyl)-8,9-dihydro-2H-pyrido[4,3,2-de]phthalazin-3(7H)-one: 1H-NMR (400 MHz, CD3OD) δ (ppm): 0.83-0.91 (m, 4H), 1.94-2.03 (m, 1H), 2.81 (s, 6H), 3.18-3.23 (m, 1H), 3.35-3.79 (m, 7H), 4.26 (s, 2H), 4.40 (d, J=7.6 Hz, 1H), 4.82 (d, J=7.2 Hz, 1H), 7.22-7.29 (m, 4H), 7.31-7.33 (m, 1H), 7.37-7.45 (m, 4H), 7.58-7.60 (d, J=8.0 Hz, 1H), 7.64-7.68 (t, J=8.0 Hz, 1H); LC-MS (ESI) m/z: 577 (M+1)+. 9-(3-(4-(cyclopropanecarbonyl)piperazine-1-carbonyl)phenyl)-8-(4-(hydroxymethyl)phenyl)-8,9-dihydro-2H-pyrido[4,3,2-de]phthalazin-3(7H)-one: 1H-NMR (400 MHz, CD3OD) δ (ppm): 0.83-0.91 (m, 4H), 1.94-2.01 (m, 1H), 3.11-3.14 (m, 1H), 3.35-3.79 (m, 7H), 4.37-4.40 (d, J=10.0 Hz, 1H), 4.55 (s, 2H), 4.38 (d, J=7.6 Hz, 1H), 4.73-4.76 (d, J=9.6 Hz, 1H), 7.12 (s, 1H), 7.20-7.30 (m, 7H), 7.34-7.38 (t, J=8.0 Hz, 1H), 7.56-7.58 (d, J=7.6 Hz, 1H), 7.62-7.66 (t, J=8.0 Hz, 1H); LC-MS (ESI) m/z: 550 (M+1)+.