Hydrogen Bromide → 3-Hydroxy-9H-dipyrido[2,3-b;4',3'-d]pyrrole-6-carbonitrile

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Reaction Conditions

Reaction Steps

A solution of 3-hydroxy-9-(2-trimethylsilanylethoxymethyl)-dipyrido[2,3-b;4′,3′-d]pyrrole-6-carbonitrile (90.9 mg, 0.267 mmol) in 1,4-dioxane (500 μL) was treated with 48% aqueous hydrobromic acid (500 μL) and heated at 75° C. for 10 min. The cooled reaction mixture was basified to pH 12 with 6N aqueous sodium hydroxide solution and then adjusted to pH 7-9 with dropwise addition of 1N hydrochloric acid. The solid was collected via centrifugation, the aqueous supernate discarded, and the solid dissolved in 1-2 mL of DMSO and purified by preparative HPLC (0-30% MeCN in water (0.1% formic acid) over 30 min, 35 mL/min) to afford the title compound as an off-white solid (19 mg, 33%). 1H NMR (DMSO-D6, 400 MHz): 12.51 (s, 1H), 9.94 (s, 1H), 8.94 (s, 1H), 8.87 (s, 1H), 8.32 (d, J=2.7 Hz, 1H), 8.08 (d, J=2.7 Hz, 1H). LCMS (Method E): RT=2.90 min, M+H+=211.

Provenance & Evidence