Hydrochloric Acid → (2'-oxospiro[furo[2,3-f][1,3]benzodioxole-7,3'-indol]-1'(2'H)-yl)acetic acid

Participants

Reaction Conditions

Reaction Steps

To a suspension of ethyl(2′-oxospiro[furo[2,3-f][1,3]benzodioxole-7,3′-indol]-1′(2′H)-yl)acetate (10.5 g, 24.5 mmol) in THF (200 mL) and water (100 mL) was added lithium hydroxide monohydrate (3.98 g, 95.0 mmol) at 0° C. The reaction mixture was stirred at 0° C. for 30 min and at ambient temperature for 17 h. The mixture was neutralized with of 4 M HCl (15.0 mL). The residue obtained upon removing the solvent was acidified by the addition of 4 M HCl (6.2 mL) to pH 3. The solid was filtered, washed with water and hexane, and dried under the reduced pressure to give the title compound (8.48 g, 87%) as a white solid: 1H NMR (300 MHz, CDCl3) δ 7.32-7.06 (m, 4H), 6.79 (d, 1H), 6.49 (s, 1H), 6.23 (s, 1H), 5.84 (m, 2H), 4.92 (m, 1H), 4.69-4.63 (m, 2H), 4.45 (m, 1H); 13C NMR (75 MHz, CDCl3) δ 177.8, 171.8, 155.8, 149.0, 142.4, 141.2, 132.0, 129.0, 124.1, 124.0, 119.2, 108.3, 103.4, 101.5, 93.5, 80.2, 58.2, 41.1; MS (ES−) m/z 338.2 (M−1).

Provenance & Evidence