Lithium Hydroxide → 2-Hydroxy-4-methyl-7-(trifluoromethyl)quinoline-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A 2M aq. LiOH sol. (125 ml) was added to a solution of 15.0 g (50.1 mmol) ethyl 4-methyl-2-oxo-7-(trifluoromethyl)-1H-quinoline-3-carboxylate in a MeOH/THF mixture (175 ml each) and the RS was subsequently heated at 60° C. for 16 h. The mixture was then concentrated in vacuo. The residue was taken up with water and adjusted to pH 2 with a 2M hydrochloric acid, followed by extraction with EtOAc. The organic layer was separated, washed with brine, dried over MgSO4 and concentrated in vacuo. As residue 12.0 g (44.2 mmol, 88%) 4-methyl-2-oxo-7-(trifluoromethyl)-1H-quinoline-3-carboxylic acid was obtained, which was used in the next step without further purification.

Provenance & Evidence