11.5 g Ethyl 4-aminomethylphenylacetate hydrochloride (m.p. 172° C.; prepared by the catalytic hydrogenation of ethyl 4-cyanophenylacetate) are suspended in 200 ml toluene. After the addition of 13.9 ml triethylamine, there is added dropwise, while cooling, a solution of 12.4 g 2-butoxy-5-chlorobenzoyl chloride in 10 ml toluene. The reaction mixture is subsequently heated under reflux for 2 hours, while stirring. After cooling, the toluene phase is treated successively with dilute hydrochloric acid, aqueous sodium bicarbonate solution and water and then evaporated. The evaporation residue is heated on a steambath with 2 N aqueous sodium hydroxide solution and the solution then filtered. The filtrate is acidified with dilute hydrochloric acid. The precipitated 4-(2-butoxy-5-chlorobenzamidomethyl)-phenylacetic acid is reprecipitated via its sodium salt and recrystallized from ethanol. The yield is 3.9 g (20% of theory); m.p. 198° C.
