NOVELTY - Preparing 2-(4-bromomethyl-phenyl)-propionic acid comprises preparing 2-chloro-1-p-tolylpropanone, p-tolyl-propionic acid, and 2-(4-(bromomethyl) phenyl)propanoic acid, where the method specifically comprises e.g. adding anhydrous aluminum trichloride and anhydrous toluene in acylation reaction kettle, dripping 2-chloro-propionyl chloride, hydrolyzing, stratifying and condensing to obtain 2-chloro-1-p-tolylpropanone, adding neopentyl glycol and tosylic acid in a condensation reaction kettle, adding 2-p-tolyl-propionate zinc, hydrolyzing, static layering and distilling.    USE - The method is useful for preparing 2-(4-bromomethyl-phenyl)-propionic acid (claimed).    ADVANTAGE - The method has simple production process, and reduces production cost and pollution. The product has high purity and high yield more than 98%, and act as intermediate in the synthesis of loxoprofen sodium, which clinically indicates that it is known as arylpropionic acid with analgesic, antiinflammatory, and anti-rheumatic effects.    DETAILED DESCRIPTION - Preparing 2-(4-bromomethyl-phenyl)-propionic acid, comprises preparing 2-chloro-1-p-tolylpropanone, p-tolyl-propionic acid, and 2-(4-(bromomethyl) phenyl)propanoic acid, where the method specifically comprises:    (i) preparing 2-chloro-1-p-tolylpropanone by: adding anhydrous aluminum trichloride and anhydrous toluene in a molar ratio of 1-20:1-30 into a dry acylation reaction kettle, cooling to 5 degrees C, stirring, slowly dripping 2-chloro-propionyl chloride according to the molar ratio, where the dripping time is 2-3 hours, stirring at 0-5 degrees C for 8 hours and reacting, adding ice water under stirring condition with a reactant and placing into an hydrolysis kettle, where the hydrolyzing temperature is controlled at 1-5 degrees C, discharging after continuously stirred for 30 minutes, then stratifying to obtain the lower layer aluminum chloride aqueous solution and organic layer, which is washed with sodium chloride aqueous solution, and entering the remaining liquid into a condensation reaction kettle;    (ii) preparing p-tolyl-propionic acid by adding neopentyl glycol and tosylic acid in a molar ratio of 1-51:1-3 into a condensation reaction kettle, then raising the temperature, stirring, refluxing and dehydrating for 32-36 hours, removing the water in the measuring tank, inspecting dehydration until no water drop is present, where the temperature in the kettle is 70 degrees C, adding 2-p-tolyl-propionate zinc, continuously raising the temperature for rearrangement reaction, after completing rearrangement, adding into a hydrolysis kettle, adding 30% 1-10 parts sodium hydroxide and 1-30 parts water for hydrolysis reaction, hydrolyzing and adding the lower layer aqueous phase into an acidifying kettle, adding upper layer of organic phase into the solvent recovery kettle for recycling toluene and byproduct chloro-pentanol, adding 30% 1-5 parts hydrochloric acid into an acidifying kettle, fully stirring, static layering to obtain the lower layer aqueous solution, subjecting the waste water for further concentrated treatment, adding organic phase into an acid distillation kettle and vacuum extracting and distilling, and    (iii) preparing 2-(4-(bromomethyl) phenyl)propanoic acid by: adding p-tolyl-propionic acid into bromination reaction kettle, adding 1-5 pts. wt. chloroform and 0.1-0.5 pts. wt. initiator azo-bis-iso-butyrynitrile, illuminating under 40-60 degrees C tungsten lamp, stirring and slowly dropping 0.05-0.1 parts bromine, after finishing dripping, continuously thermal insulating and reacting for 2 hours, after bromination reaction, adding chloroform into a distillation kettle and partially distilling off chloroform, transferring into the crystallizing kettle, crystallizing, cooling to 0 degrees C for 8-10 hours, adding into a centrifugal machine and drying to obtain 2-(4-(bromomethyl) phenyl)propanoic acid solid crude product, placing it in a refining kettle, adding 0.1-0.3 pts. wt. ethyl acetate, 0.1-0.5 pts. wt. petroleum ether, refining for 2 times, centrifuging and drying to obtain finished product.