Abstract: Propinic acid containing trifluoromethyl group was synthesized from 2-bromo-3,3,3-trifluoropropene, which was obtained via two steps:addition of 3,3,3-trifluoropropene and bromine followed by an elimination reaction. Then the reaction of magnesium, 2-bromotrifluoropropene, different initiators and carbon dioxide in tetrahydrofuran produced 1-bromo-2-trifluoromethylpropionic, 0.8 g of the product was obtained by extrated with 10% sodium carbonate solution. The purity of the product was 99.6% and the yield was 3.6%. Its structure was characterized by MS, IR, 1H NMR and 13C NMR. The main byproducts were 1,1-difluoropropadiene, 2,3-bis(trifluoromethyl)-1,3-butadiene and their [2+2] and [2+4] cycloaddition products. The suitable synthesis conditions of the reactions were determined as follows:THF was used as reaction solvent, dibromoethane as the initiator, reaction temperature for preparing the Grignard reagent was 30 ℃, the Grignard reaction temperature was 0 ℃.

Key words: bromotrifluoropropene, tetrohydrofuran, Grignard reagent, carboxylic acid, cycloaddition