Ethanol → 6-chloro-7-(4-ethynyl-2-methylphenoxy)-2-(trifluoromethyl)-2H-chromene-3-carboxylic acid

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Reaction Conditions

Reaction Steps

The product of step 1 (230 mg, 0.53 mmol) was dissolved in 3 ml of tetrahydrofuran. To the resulting solution was added a solution of lithium hydroxide (111 mg, 2.6 mmol) in 3 mL of water, followed by addition of 3 mL of ethanol. The resulting solution was heated to 80° C. for one hr, LC-MS indicated that the reaction was complete. The volatiles were removed. The residue was diluted with water, and acidified at 0° C. with dilute hydrochloric acid to pH=1.0. The product was extracted with ethyl acetate, and dried over anhydrous magnesium sulfate. After removing the volatiles, the crude product was purified by reverse phase HPLC. The product was obtained 70 mg (28.8%) of a light yellow solid: 1H NMR (CDCl3/300 MHz) 7.82 (s, 1H), 7.48(s, 1H), 7.42-7.40(m, 2H), 6.93(d, J=8.1 Hz, 1H), 6.36(s, 1H), 5.66(q, J=6.9 Hz, 1H), 3.11(s, 1H), 2.23(s, 3H). MS (ESI+) 409.0(M+1, 100). MS(ES−) 407.0(M−H, 100). HRMS (ES−) m/z calcd for (M−H; C20H11ClF3O4): 407.0292, found: 407.0317

Provenance & Evidence