Hydrochloric Acid → 3-(hydroxymethylidene)-1H-indol-2-one

Participants

Reaction Steps

To a slurry of oxindole (1.33 g, 10.0 mmol) and ethyl formate (2.42 mL, 30.0 mmol) was added 4.85 mL of 21 wt. % NaOEt in EtOH. The thick solution was stirred for 30 min at room temperature and then heated at reflux for 30 min. The solution was acidified to pH=3 with 10% aqueous HCl and 5 mL H2O was added. The solid which formed was filtered and rinsed with H2O to give the title compound (1.34 g, 83%) as a pale yellow solid.

Provenance & Evidence