反应详情

To a solution of 1,3-benzodioxol-5-ol (4.86 g, 22.0 mmol) in anhydrous tetrahydrofuran (100 mL) was added dropwise a solution of isopropyl magnesium chloride (49.6 mmol, 24.8 mL, 2.0 M solution in tetrahydrofuran) at 0° C. for 10 min. The reaction mixture was stirred for 30 min upon which time 4-chloroisatin (4.00 g, 22.0 mmol) was added in one portion. The reaction mixture was stirred at ambient temperature for 2 h and quenched by the addition of 10% aqueous hydrochloric acid (25.0 mL) and the mixture was concentrated in vacuo to dryness. The residue was diluted with ethyl acetate (100 mL), washed with saturated ammonium chloride (3×30 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo to dryness. The residue was triturated with hot diethyl ether to afford 4-chloro-3-hydroxy-3-(6-hydroxy-1,3-benzodioxol-5-yl)-1,3-dihydro-2H-indol-2-one (6.70 g, 95%) as a beige solid: mp 250-253° C.; 1H NMR (300 MHz, DMSO-d6) δ 10.30, (s, 1H), 9.04 (s, 1H), 7.20 (s, 1H), 7.12 (t, J=8.0 Hz, 1H), 6.74 (d, J=8.2 Hz, 1H), 6.70 (d, J=7.7 Hz, 1H), 6.45 (s, 1H), 6.17 (s, 1H), 5.88 (d, J=6.7 Hz, 2H); 13C NMR (75 MHz, DMSO-d6) δ 178.1, 148.6, 147.0, 145.6, 139.6, 130.6, 130.1, 129.6, 122.3, 118.6, 108.9, 108.4, 101.1, 97.4, 75.8; MS (ES−) m/z 304.2 (M−17), 302.2 (M−17).

1. additionwas added in one portion
2. customquenched by the addition of 10% aqueous hydrochloric acid (25.0 mL)
3. concentrationthe mixture was concentrated in vacuo to dryness
4. additionThe residue was diluted with ethyl acetate (100 mL)
5. washwashed with saturated ammonium chloride (3×30 mL)
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationThe filtrate was concentrated in vacuo to dryness
9. customThe residue was triturated with hot diethyl ether