Hydrochloric Acid → 1,2,3-Trichloro-5-(trifluoromethyl)benzene

Participants

Reaction Conditions

Reaction Steps

2,6-Dichloro-4-trifluoromethylaniline (3.3 kg, prepared as in Example 15) in concentrated hydrochloric acid (25 liters) was stirred for 1 hour and then cooled to -6° C. A solution of sodium nitrite (1.41 kg) in water (3 liters) was added over a period of 4 hours keeping the temperature between -5° and -12°. The mixture was then stirred between -5° and 0° until all solid had dissolved (3.5 hours). The mixture was then added in 2 liter portions over a period of 35 minutes to a solution of cuprous chloride (1.5 kg) in concentrated hydrochloric acid with stirring. The dark solution was left to stand for 30 minutes, filtered, and extracted with dichloromethane (1×15 liters, then 2×10 liters). The extracts were washed with water (2×25 liters) dried (MgSO4) and evaporated under reduced pressure to give 3,4,5-trichlorobenzotrifluoride (2.2 kg) with a boiling range of 98°-100°/40 Torr.

Provenance & Evidence