Hydrochloric Acid → 6-(3-Amino-benzoyl)-1,3-dihydro-indol-2-one

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Reaction Steps

[2-Nitro-4-(3-nitro-benzoyl)-phenyl]-malonic acid diethyl ester (2.00 g, 4.65 mmol) was dissolved in EtOH (11.5 mL) after which Sn powder (4.42 g, 37.2 mmol) was added followed by dropwise addition of concentrated HCl(aq) (13 mL). The mixture was allowed to reflux for 3 hours, filtered while hot and then allowed to cool to room temperature. The mixture was diluted with CHCl3 (200 mL) and then extracted once with H2O (200 mL). The aqueous layer was then neutralized with NaHCO3 (pH=7) and then the aqueous layer was extracted with a 95% EtOAc/5% i-prOH solution (3×200 mL). The organic layers were combined and dried over anhydrous Na2SO4. The solution was then concentrated in vacuo affording the 6-(3-Amino-benzoyl)-1,3-dihydro-indol-2-one in 44% yield (0.516 g, 2.05 mmol).

Provenance & Evidence