NOVELTY - Preparing valsartan comprises: (a) coupling of 1-triphenylmethyl-5-(4'-(bromomethyl)biphenyl-2-yl)tetrazole with L-valine methyl ester hydrochloride; (b) acylating N-((2'-(1-triphenylmethyltetrazol-5-yl)bipheyl-4-yl)methyl)-L-valine methyl ester obtained in step (a) with valeroyl chloride; (c) deprotecting N-((2'-(1-triphenylmethyltetrazol-5-yl)biphenyl-4-yl)methyl)-N-valeryl-L-valine methyl ester obtained in step (b) by organic acid; and (d) treating N-(1-oxopentyl)-N-(2'-(1H-tetrazol-5-yl)(1,1'-biphenyl)-4-yl)methyl-L-valine methyl ester obtained in step (c) with an aqueous inorganic base.    USE - The process is useful for preparing (S)-N-(1-carboxy-2-methyl-prop-1-yl)-N-pentanoyl-N-((2'-(1H-tetrazole-5-yl)-biphenyl)-4-ylmethyl)-amine (valsartan) (claimed), which is useful for treating high blood pressure and cardiac insufficiency.    ADVANTAGE - The improved process safely and simply prepares valsartan with high yield and enantiomeric purity of 99.8% in an economical and an environmental friendly manner.    DETAILED DESCRIPTION - Preparing (S)-N-(1-carboxy-2-methyl-prop-1-yl)-N-pentanoyl-N-((2'-(1H-tetrazole-5-yl)-biphenyl)-4-ylmethyl)-amine (valsartan) comprises: (a) coupling of 1-triphenylmethyl-5-(4'-(bromomethyl)biphenyl-2-yl)tetrazole with L-valine methyl ester hydrochloride in dipolar aprotic organic solvent in presence of an inorganic base and copper halide as a catalyst; (b) crude product of N-((2'-(1-triphenylmethyltetrazol-5-yl)bipheyl-4-yl)methyl)-L-valine methyl ester obtained in step (a) in situ acylated using valeroyl chloride in presence of an inorganic base, cuprous halide and a phase transfer catalyst; (c) deprotection of a trityl group of N-((2'-(1-triphenylmethyltetrazol-5-yl)biphenyl-4-yl)methyl)-N-valeryl-L-valine methyl ester obtained in step (b) by catalytic quantity of organic acid; and (d) treating N-(1-oxopentyl)-N-(2'-(1H-tetrazol-5-yl)(1,1'-biphenyl)-4-yl)methyl-L-valine methyl ester obtained in step (c) with an aqueous inorganic base.