Potassium Hydroxide → 9-(1,3-Benzodioxol-5-yl)benzo[g][1,3]benzodioxole-7,8-dicarboxylic acid

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Reaction Steps

Compound 30 (20 mg, 0.05 mmol) was refluxed with 1 M solution of KOH in MeOH (10 mL) for 24 h. Completion of the reaction, followed by the workup as described for the isolation of 31, gave a residue, which was purified by silica gel column chromatography. Elution with CH2Cl2/MeOH (2:1, v/v) as eluent yielded 32 (12 mg, 63%) as a yellow powder. mp 253° C. (decomp.); 1H NMR (DMSO-d6) δ 8.25 (s, 1H, H4), 7.53 (d, 1H, H5, J=8.7 Hz), 7.24 (d, 1H, H6, J=8.7 Hz), 6.72-6.82 (m, 3H, H2′+H5′+H6′), 5.99 (AB, 2H, 3′,4′-OCH2O—, Δδ=18.9 Hz), 5.81 (AB, 2H, 7,8-OCH2O—, Δδ=6.0 Hz); MS (FAB, positive) m/z 381 [M+H]+.

Provenance & Evidence