Triethylamine → 2-(Difluoromethyl)-5-[[(2-methyl-1-oxopropyl)amino]methyl]benzoic acid

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Reaction Steps

Add isobutyryl chloride (0.571 mL, 5.42 mmol, 1.05 equiv) to a mixture of methyl 5-(aminomethyl)-2-(difluoromethyl)benzoate hydrochloride (1.30 g, 5.17 mmol, 1.0 equiv) and triethylamine (1.51 mL, 10.85 mmol, 2.1 equiv) in DCM (50 mL) at room temperature and stir the mixture for one hour. Dilute the mixture with DCM; wash with water; then with a saturated sodium chloride aqueous solution. Separate the organic layer; dry over sodium sulfate; filter; and concentrate the filtrate under reduced pressure. Dissolve the resulting crude material in 1,4-dioxane (10 mL), and add sodium hydroxide (5 N, 2 mL, 10 mmol, 1.93 equiv). Stir the resulting suspension at 40° C. overnight. Concentrate the mixture under reduced pressure, and treat the resulting residue with 1 N aqueous hydrochloric acid until the pH reaches 3. Extract the resulting suspension with EtOAc (2×30 mL). Wash the combined organic layers with a saturated sodium chloride aqueous solution (50 mL); dry over sodium sulfate; filter; and concentrate the filtrate under reduced pressure to give the title compound as a white solid (1.32 g, 94% yield). ES/MS (m/z) 272 (M+1).

Provenance & Evidence