Hydrochloric Acid → 7-(isobutylamino)-2-(trifluoromethyl)-2H-chromene-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

The ethyl 7-(isobutylamino)-2-(trifluoromethyl)-2H-chromene-3-carboxylate (0.53 g, 1.54 mmole) was dissolved in a mixture of THF (5.0 mL) and ethanol (5.0 mL). 2.5N sodium hydroxide (1.54 mL) was added and the reaction was heated to 55° C. (oil bath) for 3 hours. The reaction was cooled to room temperature and stirred for 18 hours. The solution was condensed in vacuo to give a yellow oil. The oil was redissolved in water (20 mL), acidified with 2.4 N HCl to pH around 1 and extracted with EtOAc (2×20 mL). The combined extracts were washed with brine (20 mL), dried over MgSO4, filtered and concentrated in vacuo to give a yellow oil which was subject to prep HPLC (reverse phase) and eluted with 50-95% ACN/ water with 0.05% TFA to give a yellow solid (0.1 g, 21%). ESHRMS m/z 314.1023 (M−H, C15H15O3F3N, Calc'd 314.0999). 1H NMR (CDCl3/400 MHz) 7.78 (s, 1H), 7.01 (s, 1H), 6.24 (s, 2H), 5.60 (q, 1H, J=7.0 Hz), 2.97 (m, 2H), 1.91 (m, 1H), 0.98 (m, 6H).

Provenance & Evidence