Methanol → Methyl 2-amino-5-(trifluoromethyl)benzoate

Participants

Reaction Conditions

Reaction Steps

2-Iodo-4-(trifluoromethyl)aniline (8.0 g, 27.9 mmol), methanol (5 mL) and triethylamine (10 mL) were dissolved in dimethylformamide (50 ml) and, under a carbon monoxide atmosphere, tetrakis(triphenylphosphine)palladium (1.6 g, 1.4 mmol) was added and the mixture was stirred at 50° C. for 5 days. The solvent was evaporated and work-up according to a conventional method gave a crude product of methyl 2-amino-5-(trifluoromethyl)benzoate. The obtained crude product was dissolved in tetrahydrofuran (20 ml), lithium aluminum hydride (1.0 g, 26.3 mmol) was added under cooling, and the mixture was stirred for 2 hrs. Water (1 ml), 30% aqueous sodium hydroxide solution (1 ml) and water (3 mL) were sequentially added, the precipitate was filtered off, and the filtrate was concentrated to give a crude product of [2-amino-5-(trifluoromethyl)phenyl]methanol. Sodium nitrite (59 mg, 0.86 mmol) was dissolved in conc. sulfuric acid (0.77 mL) and, after cooling, a solution of a crude product (0.15 g, 0.78 mmol) of [2-amino-5-(trifluoromethyl)phenyl]methanol in acetic acid (1.72 ml). After stiring for 30 min. 10% aqueous potassium iodide solution (4.64 mL) was added. After stirring with heating at 70° C. for 30 min, the mixture was worked-up according to a conventional method, and the obtained crude product was purified by silica gel column chromatography (5% to 7.5% ethyl acetate/hexane) to give the title compound (96 mg, 0.32 mmol, 40%).

Provenance & Evidence