反应详情

A solid mixture of 0.52 g of 3-amino-2,4,5-trifluorobenzoic acid (Example 2) and 0.33 g of sodium nitrite is added in portions to a solution of 3 g of cupric chloride in 9 ml of water and 0.5 g of a 36% aqueous solution of hydrochloric acid. The resulting mixture is allowed to stir at 15°-25° C. for 1.5 hours and then additional water (25 ml) is added. Stirring is continued another hour at 25° C. and then 20 ml of diethyl ether is added. The layers are separated and the aqueous layer extracted with 20 ml of diethyl ether. The combined organic extracts are extracted with 5 ml of a 36% aqueous solution of hydrochloric acid and then concentrated on the rotary evaporator to give 0.45 g of 3-chloro-2,4,5-trifluorobenzoic acid as a tan solid; gas chromatography (GC) (98.8%); high performance liquid chromatography (HPLC) (84.8%); (a portion of the 3-chloro- 2,4,5-trifluorobenzoic acid was recrystallized from heptanes; mp 109°-111° C.).

1. stirringStirring
2. waitis continued another hour at 25° C.
3. customThe layers are separated
4. extractionthe aqueous layer extracted with 20 ml of diethyl ether
5. extractionThe combined organic extracts are extracted with 5 ml of a 36% aqueous solution of hydrochloric acid
6. concentrationconcentrated on the rotary evaporator