NEURAMINIC ACID DERIVATIVES OR THEIR PHARMACEUTICALLY ACCEPTABLE SALTS, OR THEIR ESTERS AND A PHARMACEUTICAL COMPOSITION EXHIBITING SIALIDASE-INHIBITING ACTIVITY Russian patent published in 1999 - IPC

FIELD: organic chemistry, biochemistry. SUBSTANCE: invention proposes derivatives of neuraminic acid of the formula (I) where R¹ is C_1-4--alkyl or C_1-4--haloalkyl; R² and R³ - hydrogen atom or C_2-25-aliphatic acyl-group; X - hydroxy-, alkoxy-group, halogen or a group of the formula R^aO- where R^a is C_2-25--aliphatic acyl-group; Y means a group of the formula R^bR^cN- or R^bR^cN-O-, where R^b and R^c - hydrogen atom or C_1-4-alkyl; Z - oxygen or sulfur atom, or their pharmaceutically acceptable salts that exhibit strong inhibiting activity with respect to sialidase and therefore they can be used for prophylaxis and treatment of influenza and other viral diseases where virus replication is sensitive to sialidase inhibitors. EFFECT: improved method of synthesis, enhanced effectiveness of compounds. 27 cl, 6 tbl, 38 ex