Potassium Hydroxide → 3-Methyl-6-(methylthio)-2-[3-(trifluoromethyl)phenyl]-4-quinolinecarboxylic acid

Participants

Reaction Steps

Potassium hydroxide (3.31 g, 59.0 mmol) in water (10 mL) was added slowly to a suspension of 5-(methylthio)-1H-indole-2,3-dione (1.9 g, 9.83 mmol) in ethanol (25 mL). 1-[3-(Trifluoromethyl)phenyl]-1-propanone (1.99 g, 9.83 mmol) was added and the mixture was heated to reflux for 1 h. The solvent was removed under reduced pressure, the residue was dissolved in water, and the aqueous mixture was washed with ether (3 times). The aqueous phase was chilled and was acidified to pH 3 with concentrated HCl. The solid material was collected by filtration, washed with water, and air dried to afford 3-methyl-6-(methylthio)-2-[3-(trifluoromethyl)phenyl]-4-quinolinecarboxylic acid (2.5 g, 67% yield). MS (m/z) 378.0 (M+H+).

Provenance & Evidence