4-Toluenesulfonyl chloride → 3-Bromo-1-(4-methylbenzene-1-sulfonyl)-1H-pyrrolo[2,3-b]pyridine

Participants

Reaction Steps

3 g (0.015 mol) of 2 in 20 mL of anhydrous THF was cooled to −78° C. and n-BuLi 2.5 M in hexanes (6.7 mL, 0.167 mol) was added dropwise. After 15 minutes of stirring, tosyl chloride in 5 mL of THF was added dropwise. The cooling bath was removed and the reaction mixture stirred at rt for 1 h. Extracted with ether and the organic phase washed with brine, dried with magnesium sulfate and concentrated in vacuo to give a white solid that was passed through a pad of silica (70% EtOAc; 30% Hexanes) to give 4.65 g (84%) of 3. 1H NMR CDCl3 8.4 (s, 1H), 8.1 (d, 2H), 7.8 (s, 2H), 7.2 (m, 3H), 2.3 (s, 3H).

Provenance & Evidence