Hydrochloric Acid → 5-Amino-2-methoxybenzotrifluoride

A suspension of 4-methoxy-3-trifluoromethyl-nitrobenzene (2.2 g) and iron powder (1.68 g) in ethanol (35 mL) and water (15 mL) is treated with a solution of concentrated hydrochloric acid (0.42 mL) in ethanol (6 mL) and water (3 mL) and the mixture is heated to reflux for approximately 1 hour. The mixture is then cooled, filtered, and concentrated under reduced pressure. The resulting oil is dissolved in ethyl acetate and extracted three times with 5% aqueous hydrochloric acid. The pooled acidic extracts are then cooled in an ice bath and basified with solid potassium carbonate, then extracted with ethyl acetate. These organic extracts are washed with saturated aqueous sodium chloride, dried over anhydrous sodium sulfate, concentrated under reduced pressure, then passed through a short column of silica gel (ethyl acetate is used as the eluant) to provide the desired compound as an amber oil.

1. temperaturethe mixture is heated
2. temperatureto reflux for approximately 1 hour
3. temperatureThe mixture is then cooled
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. dissolutionThe resulting oil is dissolved in ethyl acetate
7. extractionextracted three times with 5% aqueous hydrochloric acid
8. temperatureThe pooled acidic extracts are then cooled in an ice bath
9. extractionextracted with ethyl acetate
10. washThese organic extracts are washed with saturated aqueous sodium chloride
11. dry with materialdried over anhydrous sodium sulfate
12. concentrationconcentrated under reduced pressure

ORD record

ord-be6bc60645db44cea02910e8b409e4e0

Source dataset

uspto-grants-2002_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06462055B2