Methyl 5-nitro-2-(trifluoromethoxy)benzoate → Methyl 5-amino-2-(trifluoromethoxy)benzoate

Participants

Reaction Conditions

Reaction Steps

5-Nitro-2-trifluoromethoxybenzoic acid methyl ester (5.69 g, 21.5 mmol) was dissolved in ethanol 99.9% (80 mL) and added stannous(II)chloride dihydrate (24.2 g, 107 mmol). The suspension was stirred at 75° C. for 2 hours and then concentrated in vacuo. The residue was added ethyl acetate (100 mL) and water (50 mL) and pH was adjusted to pH 8 with 4 N sodium hydroxide (50 mL). The liquid was decanted from the fine precipitation, which occurred, and the precipitation was washed with ethyl acetate and decanted twice. The combined organic phases were washed with water saturated sodium chloride (1:1) solution (2×100 mL), dried (magnesium sulphate) and concentrated in vacuo. The residue was purified by column chromatography (120 g silica) using ethyl acetate:heptane (1:1) as eluent to give 3.8 g of 5-amino-2-trifluoromethoxybenzoic acid methyl ester.

Provenance & Evidence