744219-32-7

Example 104 Preparation of 4-[4-(tert-butoxycarbonyl)piperazin-1-yl]-3-iodo-1H-indazole: tert-butyl 4-(1H-indazol-4-yl)piperazine-1-carboxylate (5.00 g, 16.5 mmol) was dissolved in N,N-dimethylformamide and powdered potassium hydroxide (1.85 g, 33.07 mmol) and iodine (4.61 g (18.2 mmol). The reaction mixture was stirred at room temperature for 16 h and then diluted with ethyl acetate. The reaction was quenched with 15% aqueous sodium metabisulfite. The organic and aqueous phases were separated and the aqueous phase was extracted with ethyl acetate. The organic phase and extract were combined, washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuum to give the crude product. The crude product was purified by column chromatography (silica gel, eluent ratio 10:90 to 15:85 to 20:80 ethyl acetate/hexane) to give the title compound as a yellow solid (2.40 g, 35% yield). The structure of the product was confirmed by 1H NMR and mass spectrometry.

[1] Patent: US2004/167122, 2004, A1. Location in patent: Page/Page column 20
[2] Journal of Medicinal Chemistry, 2010, vol. 53, # 21, p. 7639 - 7646