Synthesis method of 2-ethoxybenzoic acid compound

The invention discloses a synthesis method of a 2-ethoxybenzoic acid compound. The synthesis method comprises the following steps of orderly adding aromatic acylaminopyridine-1-oxide, cuprous chloride and an organic solvent into a reactor, stirring the mixture at a room temperature for 25-35min, adding potassium carbonate into the mixture after complex precipitates are produced, heating the reaction system to a temperature of 125-135 DEG C to cause a reaction lasting for 10-15h, after the reaction, carrying out extraction, drying, condensation and chromatographic separation to obtain an ethoxylated product, and carrying out alkaline hydrolysis and acidification to obtain the 2-ethoxybenzoic acid compound. The synthesis method has the advantages of easy acquisition of raw materials, cheap catalyst, mild reaction system, operation simpleness, high yield and substrate universality. The synthesis method has the yield of 87% and can realize guide base removal under mild conditions.