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

Participants

Reaction Conditions

Reaction Steps

A 2 L round bottomed flask equipped with an overhead stirrer, condenser, thermocouple and heating mantle was charged with [2-Amino-4-(3-amino-benzoyl)-phenyl]-acetic acid ethyl ester (48 g, 160.9 mmol) in of ethanol (960 mL). Concentrated HCl(aq) (67 mL) was added dropwise at 21° C. The reaction was exothermic causing a rise in reaction temperature from 21° C. to 28° C. The reaction was heated at 67° C. for 1.5 h and was determined to be complete by thin layer chromatographic analysis (ethylacetate/Hexanes 8:2). The thin layer chromatography plate was viewed with short wavelength UV and I2 stain. Following ethanol evaporation, H2O (480 mL) and saturated NaHCO3(aq) (500 mL) were added to the crude product, and the resulting mixture was stirred for 15 hours. The solids were filtered and washed with H2O (2×200 mL) and methyl t-butyl ether (300 mL). The product was dried at 40° C. for 24 h to afford 6-(3-Amino-benzoyl)-1,3-dihydro-indol-2-one in 95% yield (38.6 g, 153.0 mmol).

Provenance & Evidence