Application
4-(Trifluoromethyl)nicotinic acid is a trifluoromethyl-containing aromatic compound with unique biological activity, which can be used as a precursor material for the preparation of other pesticides or medicines. 4-(Trifluoromethyl)nicotinic acid is a key intermediate of flonicamid, a highly effective insecticide.
Preparation
synthesis of 4-(Trifluoromethyl)nicotinic acid: add 5g (0.0192mol) Methyl 2,6-dichloro-4-(trifluoromethyl)nicotinate in turn to a 100mL three-necked flask, 0.3g of 10% Pd/C (water content 63.45%) ), 5.25g (0.0389mol) CH3COONa 3H2O and 20mL ethanol, after stirring and dissolving, nitrogen was replaced 3 times to discharge air, after hydrogen replacement 2 times, the reaction was stirred at room temperature for 8h under a hydrogen atmosphere until no hydrogen was absorbed to complete the reaction, and suction filtration was recovered. Palladium carbon, washed the filter cake 3 times with ethanol, the filtrate was rotary evaporated to remove the solvent, added 20 mL of water to the obtained solid, fully shaken to dissolve it, added hydrochloric acid to adjust pH=2～3, extracted 3 times with ethyl acetate, The organic phases were combined and washed three times with saturated brine, dried over anhydrous sodium sulfate, and rotary-evaporated to obtain 3.3 g of a pale yellow solid with a yield of 90.4%.
