Ethanol → 6-chloro-5-ethoxy-2-(trifluoromethyl)-2H-chromene-3-carboxylic acid

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Reaction Conditions

Reaction Steps

To the solution of ethyl 6-chloro-5-ethoxy-2-(trifluoromethyl)-2H-chromene-3-carboxylate (300mg, 0.93 mmol) in 3 mL of THF was added a solution of lithium hydroxide hydrate (156 mg, 3.7 mmol) in 4 mL of water, followed by addition of 3 mL of ethanol. The resulting solution was heated to 80° C. for four hrs. After removing the solvent, the residue was acidified at 0° C. with ice-cold dilute hydrochloric acid. The product was extracted with EtOAc. After removing the solvents, the residue was purified on reverse phase HPLC. The product was obtained as white solid (120 mg). LC-MS (ES+) 323.2(M+1, 100). 1H NMR (CDCl3/400 MHz) 8.11(s, 1H), 7.32(d, J=8.8 Hz, 1H), 6.73(d, J=8.4 Hz, 1H), 5.65(q, J=6.8 Hz, 1H), 4.12(m, 2H), 1.44(t, J=7.2 Hz, 3H). 19F NMR(CDCl3/400 MHz) −78.81(d, J=6.8 Hz). 13C NMR(CDCl3/400 MHz) 169.5, 153.5, 152.8, 134.9, 134.3, 123.4(q, J=285.8 Hz), 121.3, 115.8, 115.5, 112.8, 71.6, 70.2(q, J=33.4 Hz), 15.5. HRMS (EI+) m/z calc. For (C13H10ClF3O4) 322.0220 (M+), found:322.0223.

Provenance & Evidence