Cesium fluoride → Methyl 2-amino-5-methyl-4-(trifluoromethyl)benzoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Add cesium fluoride (184.3 g, 1.21 mol), methyl boronic acid (63.7 g, 1.05 mol, 3 mol equiv.) and bis(diphenylphosphinoferrocene)palladium(II) chloride (27.83 g, 35.1 mmol) to a solution of methyl 2-amino-5-iodo-4-trifluoromethylbenzoate (121 g, 351 mmol) in anhydrous 1,4-dioxane (2.5 L) at room temperature under an atmosphere of nitrogen and heat the mixture at 80° C. for 3 h. Allow the mixture to cool to room temperature then partition between ethyl acetate (2.5 L) and water (2.5 L) and filter through a pad of Celite® to remove the fine black suspension. Extract the aqueous phase with ethyl acetate (2×100 mL) and wash the combined organic extracts with brine (1 L). Dry over anhydrous magnesium sulfate, filter and remove the solvent under reduced pressure at 45° C. to give a red oil. Purify the residue by column chromatography on silica gel, eluting with isohexane/ethyl acetate (9:1), to give the title compound as a pale yellow crystalline solid (75.25 g, 92%). 1H NMR (300 MHz, CDCl3) δ 7.73 (s, 1H), 6.93 (s, 1H), 5.70 (s, 2H), 3.90 (s, 3H), 2.33 (s, 3H).

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