DERIVATIVES OF PYRAZOLOPYRIMIDINONE FOR IMPOTENCY TREATMENT AND METHOD FOR THEIR PREPARING Russian patent published in 2003 - IPC

FIELD: organic chemistry. SUBSTANCE: invention relates to new derivatives of pyrazolopyrimidinone of the general formula (1) or their pharmaceutically acceptable salts that can be used in treatment of impotency and to method for their preparing. In compound of the formula (1) R₁ represents (C₁-C₆)-alkyl group; R₂ represents (C₂-C₆)-alkyl group; R₃ represents (C₁-C₆)- alkyl group; R₄ represents linear or branched (C₁-C₁₀)-alkyl group, (C₃-C₆)-cycloalkyl group, phenyl possibly substituted with halogen atom, pyridinyl, substituted (C₁-C₆)-alkyl wherein substituent is taken among group including benzene, pyridine or pyrrolidine possibly substituted with (C₁-C₆)-alkyl group. Method for preparing pyrazolopyrimidinones of the formula (1) involves the following stages: interaction of chlorosulfonated compound of the formula (2) and primary amine of the formula (3) at suitable temperature and in suitable solvent to yield sulfonamide of the formula (4) (stage 1), direct interaction of sulfonamide (4) prepared on stage 1 in the presence of condensing agent, or after conversion of carboxyl group in indicated sulfonamide (4) to anhydride or chloroanhydride with pyrazolamine of the formula (5) to yield amide of the formula (6) (stage 2), cyclization of amide (6) prepared on stage 2 to yield the end compound of the formula (1) in the presence of the corresponding base and solvent (stage 3) wherein R₁,R₂,R₃,R₄ have values indicated in definition of the formula (1). EFFECT: improved preparing method, valuable medicinal properties of compounds. 8 cl, 2 dwg, 7 tbl, 70 ex