反应详情

温度

0 °C

Acetic anhydride (37.7 g) was added to 3-(2-chloro-α,α,α-trifluoro-4-tolyloxy)-benzoic acid (86% strength, 45 g) in n-butyl acetate (85.8 g) at 35° C. Sulphuric acid (98%, 12.2 g) was added slowly and the mixture cooled to 0° C. Nitric acid (90%, 10.4 g) was then added slowly over about 3 hours such that the temperature was maintained at -5 to 0° C. On completion of the nitric acid addition the reaction was quenched with water (60 g) at 0° C. The mixture was warmed to 50-60° C. and the aqueous layer removed. The solvent layer was washed with water (2×100 g) at 60° C. and the aqueous layer removed. The solvent and acetic acid were removed by distillation to give 2-nitro-5-(2-chloro-α,α,α-trifluoro-4-tolyloxy) benzoic acid (85%), 2'-nitro isomer (7.5 to 8.5 pph), total dinitro's (~0.5 pph).

1. temperaturewas maintained at -5 to 0° C
2. customwas quenched with water (60 g) at 0° C
3. temperatureThe mixture was warmed to 50-60° C.
4. customthe aqueous layer removed
5. washThe solvent layer was washed with water (2×100 g) at 60° C.
6. customthe aqueous layer removed
7. customThe solvent and acetic acid were removed by distillation