Potassium Carbonate → 2-Fluoro-4-((trimethylsilyl)ethynyl)aniline

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Reaction Steps

The product of Step B, 3,4-difluoro-2-[[2-fluoro-4-(trimethylsilylethynyl)phenyl]amino]benzoic acid (3.99 g, 11.0 mmol), was dissolved in MeOH (200 mL), to which was added K2CO3 (3.03 g, 22.0 mmol). This mixture was stirred at room temperature for 15 hours, then the reaction solvent removed under reduced pressure. The resulting residue was dissolved in water (50 mL), to which was added 1 M HCl until the pH=4. The resulting pale brown precipitate was collected by filtration and dried to afford the desired product (3.17 g, 99%); m.p. (EtOAc/hexanes) 160-162° C. 1H NMR [400 MHz, (CD3)2SO] δ 13.70 (br s, 1 H), 9.24 (br s, 1 H), 7.82 (ddd, J=9.2, 6.1, 2.1 Hz, 1 H), 7.38 (dd, J=12.0, 1.9, 1 H), 7.21 (ddd, J=8.4, 1.9, 0.8 Hz, 1 H), 7.16 (td, J=9.5, 7.3 Hz, 1 H), 6.96 (ddd, J=8.9, 8.4, 5.4 Hz, 1 H), 4.15 (s, 1 H). Anal. Calcd for C15H8F3NO2: C, 62.4; H, 3.1; N, 4.7. Found: C, 62.4; H, 3.2; N, 4.6. Step D: Preparation of 2-[(4-ethyl-2-fluorophenyl)amino]-3,4-difluorobenzoic acid

Provenance & Evidence