反应详情

50 g of 3-fluoro-4-methyl-benzoic acid are initially introduced into 100 ml of concentrated sulphuric acid, and a mixture consisting of 26 g of 98% strength nitric acid and 40 g of concentrated sulphuric acid is added dropwise at 20°-25°, while cooling with ice. The mixture is subsequently stirred at room temperature for 1 hour. The batch is then poured onto ice-water and the crystals are filtered off with suction and washed thoroughly with water. After drying and recrystallization from toluene, 48 g (74.3% of theory) of 2-nitro-4-methyl-5-fluorobenzoic acid of melting point m.p.: 163°-5° C. are obtained.

1. additionis added dropwise at 20°-25°
2. temperaturewhile cooling with ice
3. additionThe batch is then poured onto ice-water
4. filtrationthe crystals are filtered off with suction
5. washwashed thoroughly with water
6. customAfter drying
7. customrecrystallization from toluene, 48 g (74.3% of theory) of 2-nitro-4-methyl-5-fluorobenzoic acid
8. customare obtained