Sodium Hydroxide → 5-Hydroxydiclofenac

Participants

Reaction Steps

A solution of 1-(2,6-dichlorophenyl)-5-hydroxy-2-indolinone (2.0 g, 6.8 mmol) in 25 mL of 2.5N NaOH is heated at reflux for 2 hours. The cool reaction mixture is diluted with 20 mL of water and washed with ethyl ether. The basic layer is acidified with concentrated HCl and extracted with ethyl acetate (2×25 mL). The organic phase is washed with brine and dried (Na2SO4). Removal of solvent affords the product (2.0 g, 95%) as a brown foam (of suitable purity for use in the next step).

Provenance & Evidence