[CH3:1][O:2][C:3]1[N:4]=[CH:5][C:6]([N:11]2[CH2:20][CH2:19][C:14]3(OCC[O:15]3)[CH2:13][CH2:12]2)=[N:7][C:8]=1[O:9][CH3:10].[OH-].[Na+].C([O-])([O-])=O.[K+].[K+]>Cl>[CH3:1][O:2][C:3]1[N:4]=[CH:5][C:6]([N:11]2[CH2:20][CH2:19][C:14](=[O:15])[CH2:13][CH2:12]2)=[N:7][C:8]=1[O:9][CH3:10]As shown in step 9-iv of Scheme 9, A suspension of Compound 1030 (2.46 g, 8.745 mmol) in 6N aq. HCl (43 mL) was stirred at room temperature for 2 hours. The crude reaction mixture was neutralizes at ˜4° C. by the slow addition of 6N NaOH followed by the addition of 1N aq. K2CO3). The reaction was extracted with EtOAc (3×) and the combined organics dried (MgSO4), followed by concentration under reduced pressure to give 1-(5,6-dimethoxypyrazin-2-yl)piperidin-4-one as an off white semi solid (Compound 1031, 1.51 g, 73%), which was used in the next step without further purification: 1H NMR (CDCl3, 300 MHz) δ 7.33 (s, 1H), 4.07 (s, 3H), 4.04 (s, 3H), 3.86 (m, 4H), 2.62 (m, 4H) ppm.
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