Synthesis Of Fluorine-containing Aromatic Carboxylic Acid

Because of the properties of fluorine, fluorinated aromatic compounds have four characteristics:analog effects, fat-soluble penetration effect, electronic effect and the obstruction effect. fluorinated aromatic compounds are mainly used as pharmaceuticals, pesticides and other biological active substances, and also can be used as dye intermediates, liquid crystal, etc. The synthesis of four Fluorine-containing aromatic carboxylic acids was studied in this paper.p-Fluoromandelic acid was synthesised from p-fluorobenzaldehyde and chloroform in the presence of sodium hydroxide solution. p-Fluorophenylacetic acid was obtained via reduction of p-Fluoromandelic acid.3-(4-fluorophenyl) acrylic acid was synthesised by the Perkin reaction from p-fluorobenzaldehyde and acetic .anhydride in the presence of alkaline catalyst,3-(4-fluorophenyl) propionic acid was obtained via reduction of 3-(4-fluorophenyl) acrylic acid. Catalytic Hydrogenation reduction and hydrazine hydrate reduction were studied in 3-(4-fluorophenyl)acrylic acid's reduction.o-Fluorophenylacetic acid was synthesised from o-nitrochlorobenzene and cyanoacetate. Because of low yield of nucleophilic substitution, this method has, no practical value. The synthesis of.2,3-difluorophenylacetic acid was studied by two methods. The first method is from single-Ethyl potassium oxalate and o-fluoroaniline. The second method is from chloroacetyl chloride and o-fluoroaniline.