2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 1H-Pyrrolo[2,3-B]pyridine-5-carboxaldehyde, 1-[(1,1-dimethylethyl)dimethylsilyl]-

Participants

Reaction Steps

To a stirred solution of the alcohol 13 (54 mg, 0.20 mmol) in a mixture of CH2Cl2 (15 mL) and 0.2 M pH 7 phosphate buffer (0.15 mL) was added DDQ (53 mg, 0.23 mmol) in three equal portions. When TLC analysis showed complete consumption of the starting material, the mixture was diluted with saturated aqueous NaHCO3 (16 mL) and stirred vigorously for 1 h. The mixture was then extracted with AcOEt (2×). The combined organic solutions were washed with saturated brine (1×), dried (MgSO4) and concentrated. The residue was purified by PTLC with benzene as eluent to afford aldehyde 16 (11 mg, 21%). 1H NMR (400 MHz; CDCl3) δ 0.66 (s, 6H), 0.94 (s, 9H), 6.67 (d, J=3.5 Hz, 1H), 7.34 (d, J=3.5 Hz, 1H), 8.37 (d, J=2.0 Hz, 1H), 8.76 (d, J=2.0 Hz, 1H), 10.11 (s, 1H).

Provenance & Evidence