Sodium Hydroxide → 4-methyl-2-oxo-1-(tetrahydro-2H-pyran-4-yl)-7-(trifluoromethyl)-1,2-dihydroquinoline-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of 330 mg (0.86 mmol) ethyl 4-methyl-2-oxo-1-(tetrahydro-2H-pyran-4-yl)-7-(trifluoromethyl)-1,2-dihydroquinoline-3-carboxylate in ethanol (6 ml) and water (0.6 ml) was added 140 mg (3.45 mmol) NaOH at RT. The reaction mixture was stirred at 80° C. for 16 h. Then the mixture was evaporated to dryness and the residue was diluted with water (5 ml) and acidified with 2N HCl to pH ˜3. The aq. part was extracted with ethyl acetate (3×10 ml). The combined organic layers were washed with water (10 ml), brine (10 ml), dried over anhydrous Na2SO4 and concentrated in vacuum to give 280 mg (0.79 mmol, 91%) 4-methyl-2-oxo-1-(tetrahydro-2H-pyran-4-yl)-7-(trifluoromethyl)-1,2-dihydroquinoline-3-carboxylic acid which is used in the next step without further purification.

Provenance & Evidence