Imidazole → 5-[[(1,1-Dimethylethyl)dimethylsilyl]oxy]-1H-indazole

Beteiligte Stoffe

Reaktionsschritte

A solution of 1H-indazol-5-ol (25 g, 186.38 mmol, 1.00 equiv), imidazole (31.7 g, 466.18 mmol, 2.50 equiv) and tert-butyl(chloro)dimethylsilane (33.8 g, 224.25 mmol, 1.20 equiv) in N,N-dimethylformamide (100 mL) was stirred at room temperature for 2 h. The reaction was quenched by the addition of water/ice (200 mL). The precipitate was collected by filtration and dried in a vacuum oven to give 45 g (97%) of 5-(tert-butyldimethylsilyloxy)-1H-indazole as a brown solid. 1H NMR (300 MHz, CDCl3): δ 8.00 (s, 1H), 7.40 (d, J=9.0 Hz, 1H), 7.15 (d, J=9.0 Hz, 1H), 7.02 (dd, J=9.0 Hz, 2.4 Hz, 1H), 1.03 (s, 9H), 0.24 (s, 6H) ppm. LCMS (method D, ESI): RT=1.66 min, m/z=249.0 [M+H]+.

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