[CH3:1][O:2][C:3]1[C:11]([O:12][CH3:13])=[CH:10][C:9]2[C:5](=[CH:6][N:7]([CH2:14][O:15][CH2:16][CH2:17][Si:18]([CH3:21])([CH3:20])[CH3:19])[N:8]=2)[CH:4]=1.[Li]CCCC.[C:27](Cl)(=[O:29])[CH3:28].[NH4+].[Cl-]>C1COCC1>[CH3:1][O:2][C:3]1[C:11]([O:12][CH3:13])=[CH:10][C:9]2[C:5](=[C:6]([C:27](=[O:29])[CH3:28])[N:7]([CH2:14][O:15][CH2:16][CH2:17][Si:18]([CH3:19])([CH3:21])[CH3:20])[N:8]=2)[CH:4]=1The title compound was prepared in a similar manner as described by G. Luo et al., J. Org. Chem. 2006, 71, 5392-5395: To a solution of 5,6-dimethoxy-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-indazole (200 mg, 0.65 mmol) in THF (5 mL) at −78° C. was added dropwise a 2.5 M solution of n-BuLi in hexanes (0.29 mL, 0.71 mmol). The reaction mixture was stirred at −78° C. for 20 min. Acetyl chloride (0.07 mL, 0.97 mmol) was then added dropwise, and the mixture was stirred at RT for 16 h. Saturated aqueous NH4Cl solution was added to the reaction mixture, followed by stirring for 30 min. The aqueous phase was extracted twice with EtOAc and the combined organics were washed with brine, dried (Phase separator) and evaporated to give the crude title compound which was used directly in the next step without further purification.
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