Triethylamine → Ethyl 3-(4-(5-fluoro-2,2-dimethyl-2,3-dihydrobenzofuran-7-carboxamido)phenyl)-2-methylpropanoate

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Reaction Steps

5-fluoro-2,2-dimethyl-2,3-dihydrobenzofuran-7-carboxylic acid (803) (Compound was prepared in a similar manner as that described for the synthesis of (735) (101.3 mg, 0.482 mmol) was dissolved in dichloromethane (4 mL) and ethyl 3-(4-aminophenyl)-2-methylpropanoate (646) (100 mg, 0.482 mmol), triethyl amine (0.4 mL, 2.89 mmol), and 1-propanephosphonic acid cyclic anhydride (0.34 mL, 0.58 mmol, 50% in ethyl acetate) were added and stirred overnight at room temperature. The reaction was purified in vacuo and purified by flash column chromatography on silica gel with hexanes and EtOAc to give ethyl 3-(4-(5-fluoro-2,2-dimethyl-2,3-dihydrobenzofuran-7-carboxamido)phenyl)-2-methylpropanoate. The ester was dissolved in tetrahydrofuran (1.0 mL), methanol (1.0 mL) and water (3 mL). Lithium hydroxide was added and the reaction was stirred at room temperature for 4 h. The mixture was acidified with 1M HCl and diluted with EtOAc (3 mL). The organic layer was washed with brine (3 mL), dried over sodium sulfate and filtered. The filtrate was concentrated in vacuo to yield 3-(4-(5-fluoro-2,2-dimethyl-2,3-dihydrobenzofuran-7-carboxamido)phenyl)-2-methylpropanoic acid (97). 1H NMR (400 MHz, CDCl3) δ 9.53 (br, 1H), 7.66 (dd, J=9.9, 2.6 Hz, 1H), 7.57 (d, J=8.4 Hz, 2H), 7.19 (d, J=8.4 Hz, 2H), 7.02 (dd, J=9.9, 2.6 Hz, 1H), 3.13-3.00 (m, 3H), 2.72 (m, 2H), 1.60 (s, 6H), 1.19 (d, J=8.0 Hz, 3H).

Provenance & Evidence