4-Toluenesulfonyl chloride → 4-chloro-1-tosyl-1H-pyrrolo[2,3-b]pyridine

Participants

Reaction Steps

Add NaOH (3.6 g, 90.2 mmol) as solution in H2O (14 mL) to a solution of 4-chloroazaindole 24 (0.84 g, 5.50 mmol), TsCl (1.154 g, 6.053 mmol) and Bu4NHSO4 (16 μL, 50% in H2O) in toluene (16 mL). After stirring the reaction medium for 2.5 h at room temperature, the two-phase reaction medium is then extracted with EtOAc (2×), dried (MgSO4) and concentrated under vacuum. Flash chromatography gives 25 (1.33 g, 78%) as a white solid: 1H NMR (CDCl3) δ 8.28 (d, 1H, J=5.1 Hz), 8.04 (dd, 2H, J=8.5, 2.0 Hz), 7.75 (d, 2H, J=4.0 Hz), 7.26 (d, 1H, J=8.4 Hz), 7.17 (d, 1H, J=5.1 Hz), 6.67 (d, 1H, J=4.2 Hz), 2.37 (s, 3H), TLC (EtOAc at 40%/heptane) Rf=0.50, m/z obs.=307 (M+1), 308.9.

Provenance & Evidence