Continuous process for manufacturing aqueous solutions of alkaline salts of arylacetic acids and an apparatus for the same

Continuous preparation of an aqueous solution of an alkali metal salt of an arylacetic acid of formula (I) comprises: (a) mixing an arylacetonitrile of formula (II) with an aqueous alkali metal hydroxide solution (MOH) at a molar ratio MOH/(II) of 1.05-1.20; (b) introducing this mixture into a reaction zone at atmospheric pressure or higher and 100-180 degrees C for up to 60 minutes; (c) transferring the mixture to a separation zone; (d) transferring the mixture to a stripping zone; (e) optionally treating the mixture with a neutralising agent in a mixing zone; and (f) recovering the required solution of (I). R = 1-10C aliphatic hydrocarbon, halo, 1-6C alkoxy or phenoxy; M = alkali metal; n = 0-5; x = 1 or 2; and n + x ≤ 6.