5-Bromoisatin → 6-Bromo-3-methyl-2-[3-(trifluoromethyl)phenyl]-4-quinolinecarboxylic acid

Participants

Reaction Conditions

Reaction Steps

Potassium hydroxide (29.8 g, 531 mmol) in water (49.2 mL) was added to an orange suspension of 5-bromoisatin (20 g, 88 mmol) in ethanol (172 mL). 1-[3-(Trifluoromethyl)phenyl]-1-propanone (19.68 g, 97 mmol) was added and the mixture was heated to 85° C. for 3 h. The solvent was removed under reduced pressure. The residue was diluted with water (400 mL) and stirred overnight. The aqueous mixture was cooled to 0° C. and adjusted to pH˜3 with concentrated HCl. The solid was collected by filtration and dried in a vacuum oven at 70° C. for 3 days to afford 6-bromo-3-methyl-2-[3-(trifluoromethyl)phenyl]-4-quinolinecarboxylic acid (42 g, >99% yield). This material was used without further purification. MS (m/z) 411.8 (M+H+).

Provenance & Evidence