18-Crown-6 → HCID 86667083, compound

Participants

Reaction Steps

To a stirred solution of tert-butyl 2-bromo-9-methyl-5,7,8,9-tetrahydro-6H-pyrido[3′,4′:4,5]pyrrolo[2,3-b]pyridine-6-carboxylate (732 mg, 2.0 mmol) in CH2Cl2 (20 mL) at room temperature was added 18-crown-6 (53 mg, 0.20 mmol) followed by addition of KMnO4 (474 mg, 3.0 mmol) in small portions over 20 min. The reaction mixture was stirred at room temperature for 17 h, quenched with saturated sodium metabisulfite solution (20 ml) and extracted with CH2Cl2 (3×20 mL). The combined extracts were dried over sodium sulfate, filtered, and concentrated. Flash chromatography (40 g ISCO column, 100:0 to 65:35 hexanes/EtOAc gradient) gave the title compound (134 mg, 18%) as an orange solid: 1H NMR (500 MHz, DMSO-d6) δ 8.30 (d, J=8.1 Hz, 1H), 7.36 (d, J=8.1 Hz, 1H), 4.22 (t, J=6.4 Hz, 2H), 3.80 (s, 3H), 3.05 (t, J=6.4 Hz, 2H), 1.59 (s, 9H); ESI MS m/z 380 [M+H]+.

Provenance & Evidence