The acylation of primary and secondary amines by 5-phenyltetrazol-2-ylacetyl chloride leads to the corresponding tetrazolylacetamides irrespective of the nature of the substituent in the structure of the amine. ... Keywords: 5-phenyltetrazol-2-ylacetamide, 5-phenyltetrazol-2-ylacetyl chloride, acylation. ... Tetrazolylacetic acids and their derivatives are regarded as potential biologically active compounds. A special position is occupied by the amides of tetrazolylacetic acids, ...