Sodium Hydroxide → HCID 68599012, compound

Participants

Reaction Conditions

Reaction Steps

A suspended mixture of methyl 2-[(2′-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-1′(2′H)-yl)methyl]-1,3-oxazole-4-carboxylate (0.88 g, 2.1 mmol) and sodium hydroxide (4.00 g, 10.0 mmol) in water (50 mL) and methanol (50 mL) was stirred at 60° C. for 2 h. The reaction mixture was concentrated in vacuo to remove most of methanol and acidified with concentrated hydrochloric acid to pH 1-2. The solid residue was filtered off, washed with water (50 mL) and dried in vacuo to afford 2-[(2′-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-1′(2′H)-yl)methyl]-1,3-oxazole-4-carboxylic acid (0.64 g, 75%) as a colorless solid: 1H NMR (300 MHz, DMSO-d6) δ 8.24 (s, 1H), 7.29-6.95 (m, 4H), 6.55 (s, 1H), 6.37 (s, 1H), 5.08 (ABq, 2H), 4.74 (ABq, 2H), 4.44 (t, J=8.7 Hz, 2H), 3.01-2.80 (m, 2H); MS (ES−) m/z 403.4 (M−1).

Provenance & Evidence