[Cl:1][C:2]1[CH:3]=[C:4]([C:12]#[N:13])[C:5]2[C:6](I)=[N:7][NH:8][C:9]=2[CH:10]=1.[O:14]1[CH:19]=[CH:18][CH2:17][CH2:16][CH2:15]1.[CH2:20]1COCC1>>[Cl:1][C:2]1[CH:3]=[C:4]([C:12]#[N:13])[C:5]2[C:6]([CH3:20])=[N:7][N:8]([CH:19]3[CH2:18][CH2:17][CH2:16][CH2:15][O:14]3)[C:9]=2[CH:10]=1A mixture of 6-chloro-3-iodo-1H-indazole-4-carbonitrile (2.0 g, 6.59 mmol), dihydropyran (1.09 g, 13.18 mmol), and TsOH monohydrate (127 mg, 0.659 mmol) in THF (40 mL) under nitrogen was heated at 80° C. overnight. The reaction mixture was quenched with water (40 mL) and extracted with EtOAc (50 mL×3). The combined extracts were washed with brine, dried (MgSO4), filtered, and concentrated in vacuo. The residue was purified by SiO2 chromatography eluting with petroleum ether/EtOAc (5:1) to afford 6-chloro-3-methyl-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole-4-carbonitrile as white solid (2 g, 78.4%). MS (ESI): m/z=388 [M+1]+.
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