反应详情

A stirring solution of 240 mg (1.03 mmol) of 3-Methyl-1 tert-butoxycarbonyl-pyrazolo[3,4-b]pyridine, prepared as in Part B, in 10 mL of CCl4 is heated to reflux, and then a mixture of 220 mg (1.23 mmol, 1.2 equiv) of N-bromosuccinimide and 25 mg (0.10 mmol, 0.1 equiv) of benzoyl peroxide is added all at once as a solid. The resulting solution is heated at reflux for 3.5 h, then cooled to RT. The reaction mixture is filtered through a pad of Celite to remove the precipitated succinimide, and the solvent is removed in vacuo. Purification of the crude material by silica gel flash column chromatography using hexane/EtOAc 3/1 as eluent afforded 170 mg of the title compound as a white solid: 1H NMR (CDCl3, 400 MHz) δ8.75 (dd, 1H, J=1.4, 4.6), 8.21 (dd, 1H, J=1.4, 8.0), 7.32 (dd, 1H, J=4.6, 8.0), 4.74 (s, 2H), 1.70 (s, 9H).

1. temperatureto reflux
2. additionis added all at once as a solid
3. temperatureThe resulting solution is heated
4. temperatureat reflux for 3.5 h
5. filtrationThe reaction mixture is filtered through a pad of Celite
6. customto remove the precipitated succinimide
7. customthe solvent is removed in vacuo
8. customPurification of the crude material by silica gel flash column chromatography