Hydrochloric Acid → 3-hydroxy-3-(5-hydroxy-3-methyl-1,2-benzisoxazol-6-yl)-1-(4-methoxybenzyl)-1,3-dihydro-2H-indol-2-one

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 3-methyl-1,2-benzisoxazol-5-ol (Lindemann, et al Justus Liebigs Annalen der Chemie 1927, 456:308) (3.10 g, 20.8 mmol) in 1,2-dichloroethane (200 mL) was added isopropylmagnesium chloride (10.4 mL, 2.0 M solution in tetrahydrofuran, 20.8 mmol) at 0° C. The mixture was stirred at 0° C. for 1 h and then at ambient temperature for 2 h. 1-(4-methoxybenzyl)-1H-indole-2,3-dione (5.3 g, 19.8 mmol) was added and the reaction mixture was stirred at reflux for 120 h. The mixture was cooled to 0° C. and 5% w/v hydrochloric acid was added. The organic phase was separated, washed with water and brine, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo. The residue was subjected to column chromatography eluted with ethyl acetate/hexanes (1/1) to afford 3-hydroxy-3-(5-hydroxy-3-methyl-1,2-benzisoxazol-6-yl)-1-(4-methoxybenzyl)-1,3-dihydro-2H-indol-2-one (0.87 g, 10%): 1H NMR (300 MHz, DMSO-d6) δ 9.68 (s, 1H), 8.01 (s, 1H), 7.37-6.76 (m, 10H), 4.83 (ABq, 2H), 3.70 (s, 3H), 2.46 (s, 3H); MS (ES+) m/z 415.0 (M−1).

Provenance & Evidence