Triethylamine → Benzyl 4-(2-amino-4-fluoro-5-nitrophenyl)-2,2-dimethylbut-3-ynoate

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-bromo-5-fluoro-4-nitroaniline (23.0 g, 0.1 mol) in Et3N (250 mL) was added benzoic 2,2-dimethylbut-3-ynoic anhydride (59.0 g, 0.29 mol), CuI (1.85 g) and Pd(PPh3)2Cl2 (2.3 g) at room temperature. The mixture was stirred at 80° C. overnight. After cooling to room temperature, the reaction was quenched with water and the aqueous layer was extracted with ethyl acetate (100 mL×3). The combined organic layer was dried over anhydrous Na2SO4, the solvent was evaporated in vacuo. The residue was purified by chromatography on silica gel (10% ethyl acetate in petroleum ether) to give benzyl 4-(2-amino-4-fluoro-5-nitrophenyl)-2,2-dimethylbut-3-ynoate (20.0 g, 56%). 1H NMR (400 MHz, CDCl3) 8.05 (d, J=8.4 Hz, 1 H), 7.39-7.38 (m, 5 H), 6.33 (d, J=13.2 Hz, 1 H), 5.20 (s, 2 H), 4.89 (br s, 2 H), 1.61 (s, 6 H).

Provenance & Evidence