NOVELTY - alpha , alpha -Dimethyl-4-(1-hydroxy-4-(4-(hydroxy-diphenylmethyl)-1-piperidinyl)butyl)phenyl acetate is dissolved in methanol and aqueous sodium hydroxide is added to mixture, and reacted. The obtained residue is dissolved in water. The mixture is filtered, dried and recrystallized, to obtain white crystals. The white crystals are dissolved in ethanol, and heated. Activated carbon is added, bleached and filtered. The filtrate is cooled and filtered. The obtained crude product is dissolved in acetone, heated, filtered and vacuum dried, to obtain fexofenadine hydrochloride.    USE - Synthesis of fexofenadine hydrochloride (claimed).    ADVANTAGE - The method enables economical synthesis of fexofenadine hydrochloride with high yield, without environmental pollution.    DETAILED DESCRIPTION - alpha , alpha -Dimethyl phenylacetic acid is dissolved in ethanol such that the solution has molar concentration of alpha , alpha -dimethyl phenylacetic acid in ethanol of 1.5-2 mol/L. 2-3 wt.% alpha , alpha -Dimethyl phenylacetic acid is added and reacted with phosphotungstate/silica-supported heteropolyacid catalyst for 2-3 hours and catalyst is separated. The ethanol filtrate is evaporated under reduced pressure. The residue is dissolved in dichloromethane, washed with saturated aqueous sodium bicarbonate solution and water, dried with anhydrous magnesium sulfate and filtered. The filtrate is evaporated under reduced pressure to remove solvent, and residues are removed by vacuum distillation at 130-133 degrees C, to form fraction of colorless transparent liquid containing alpha , alpha -dimethylbenzeneacetate. Anhydrous aluminum chloride is dissolved in dichloromethane such that the solution has molar concentration of anhydrous aluminum chloride in dichloromethane of 1-1.5 mol/L. 4-Chlorobutyryl chloride is added to ice-salt bath and cooled to -3 degrees C to -5 degrees C. alpha , alpha -Dimethylbenzene acetate and anhydrous aluminum chloride are added. The molar ratio of 4-chlorobutyryl chloride and alpha , alpha -dimethylbenzene acetate is 1.2-1.6:1:1. The mixture is reacted for 5-8 hours, and the reaction mixture is added to mixture of concentrated hydrochloric acid and ice, and the aqueous layer is extracted for 3 times with dichloromethane. The organic phases are combined, washed with water, 10% aqueous sodium hydroxide solution and saturated brine, dried with anhydrous magnesium sulfate and filtered. The filtrate is distilled to remove solvent. The residue is purified by silica gel column chromatography, to obtain pale yellow oil containing 4-(4-chloro-1-oxobutyl)- alpha , alpha -dimethylphenylacetate. 4-(4-Chloro-1-oxobutyl)- alpha , alpha -dimethylphenylacetate and ethyl acetate are dissolved in 95% ethanol, such that the solution has molar concentration of 4-(4-chloro-1-oxobutyl)- alpha , alpha -dimethylphenylacetate in ethanol of 0.2-0.25 mol/L, to obtain ethyl-4-(4-chloro-1-oxobutyl)- alpha , alpha -dimethylphenylacetate. 6-7 wt.% Sodium boron hydride is added to ethyl-4-(4-chloro-1-oxobutyl)- alpha , alpha -dimethylphenylacetate, reacted at room temperature for 3-4 hours, and dilute hydrochloric having pH of 5-6 is added, and the ethanol is evaporated under reduced pressure. The residue is dissolved in dichloromethane, washed with water and saturated brine, dried with anhydrous magnesium sulfate and filtered. The methylene chloride in filtrate is evaporated, and residue is purified by silica gel column chromatography, to obtain pale yellow oil containing 4-(4-chloro-1-hydroxybutyl)- alpha , alpha -dimethylphenylacetate. The 4-(4-chloro-1-hydroxybutyl)- alpha , alpha -dimethylphenylacetate is dissolved in ethyl acetate or dimethylformamide such that the solution has molar concentration of 4-(4-chloro-1-hydroxybutyl)- alpha , alpha -dimethylphenylacetate in ethyl acetate or dimethylformamide of 0.15-0.25 mol/L. Potassium iodide, potassium carbonate and alpha , alpha -diphenyl-4-piperidinemethanol are added to 4-(4-chloro-1-hydroxybutyl)- alpha , alpha -dimethylphenylacetate, such that the mass ratio of 4-(4-chloro-1-hydroxybutyl)- alpha , alpha -dimethylphenylacetate, potassium iodide, potassium carbonate and alpha , alpha -diphenyl-4-piperidinemethanol is 18-22:15-20:15-20:1, heated at 70-80 degrees C for 24-28 hours and filtered. The dimethylformamide in filtrate is distilled. The residue is dissolved in dichloromethane, washed with water to neutral, dried with anhydrous magnesium and filtered. The solvent in filtrate is distilled and residue is purified by silica gel column chromatography, to obtain white powdery solid containing alpha , alpha -dimethyl-4-(1-hydroxy-4-(4-(hydroxy-diphenylmethyl)-1-piperidinyl)butyl)phenyl acetate. The alpha , alpha -dimethyl-4-(1-hydroxy-4-(4-(hydroxy-diphenylmethyl)-1-piperidinyl)butyl)phenyl acetate is dissolved in methanol and 10% aqueous sodium hydroxide is added to mixture such that the mixture has molar concentration of alpha , alpha -dimethyl-4-(1-hydroxy-4-(4-(hydroxy-diphenylmethyl)-1-piperidinyl)butyl)phenyl acetate of 0.035-0.04 mol/L, and reacted for 3-4 hours. The volume ratio of methanol and 10% aqueous sodium hydroxide is 3-4:1. The methanol in mixture is distilled off under reduced pressure. The residue is dissolved in water, and 10% acetic acid solution is added to adjust pH to 4-5. The mixture is filtered, and the cake is dried and recrystallized from methanol, to obtain white crystals. The white crystals are dissolved in 60% ethanol such that solution has molar concentration of 0.1-0.15 mol/L, and heated at 70-75 degrees C. Concentrated hydrochloric acid is dripped and pH is adjusted to 2.5-3. The predetermined amount of activated carbon is added, bleached for 20-30 minutes and filtered. The filtrate is cooled to 0-2 degrees C and filtered. The filter cake is washed with ethanol and dried, to obtain crude product. The crude product is dissolved in acetone, heated for 3-4 hours, filtered and vacuum dried, to obtain fexofenadine hydrochloride.