Ethanol → 6-[(1E)-3-amino-3-oxoprop-1-enyl]-8-chloro-2-(trifluoromethyl)-2H-chromene-3-carboxylic acid

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Reaction Conditions

Reaction Steps

The product of step 1 was dissolved in 3 mL of THF and treated with a solution of 0.13 g (2.55 mmol) lithium hydroxide hydrate in 3 mL of water. The mixture was treated with 3 mL of ethanol and heated to 80° C. for two hrs. The volatiles were removed, the residue was acidified at 0° C. to pH=1.0 with dilute hydrochloric acid. The product was extracted with ethyl acetate, washed with brine and dried over anhydrous magnesium sulfate. Concentration of the organic fraction afforded 0.169 g (48.6%) of an off-white solid: 1H NMR(DMSO/300 MHz) 7.87(s, 1H), 7.70(d, J=2.1 HZ, 1H), 7.55(d, J=2.1 Hz, 1H), 7.48(d, J=15.9 Hz, 1H), 6.63(d, J=15.9, 1H), 5.96(q, J=6.6 Hz, 1H). MS (ESI+) 348.0 (M+1, 100). MS(ES−) 346.0(M−1, 100). HRMS (ES−) m/z calcd for (M−H; C14H8ClF3NO4): 346.0088, found 346.0078.

Provenance & Evidence