Process for obtaining valine derivatives useful for obtaining a pharmaceutically active compound

The invention provides a method for obtaining the intermediate (II), useful for manufacturing Valsartan and a drug directed to a treatment of arterial hypertension or heart failure. The process comprises a) Imination of the aldehyde group of a compound (VII) by L-Valine (IV) salts with organic or inorganic bases and a polar solvent or water, where X means halogen or an -OSO2R group, where R is CF3, tolyl, methyl or F; to give an imine-type compound (VIII), where B+ is the protonated form of an organic base or an alkaline cation; b) Reduction of the imine group of the compound (VIII) followed by acidification, to give the compound (VI); and c) N-Acylation of the compound (VI) with valeryl chloride to give the compound (II). Steps a) and b) can be performed in a "one pot" reaction.